Commit Graph

753 Commits

Author SHA1 Message Date
Masahiro Yamada
d4323e8350 modpost: merge fromsec=DATA_SECTIONS entries in sectioncheck table
You can merge these entries.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-28 20:36:52 +09:00
Masahiro Yamada
a9bb3e5d57 modpost: remove is_shndx_special() check from section_rel(a)
This check is unneeded. Without it, sec_name() will returns the null
string "", then section_mismatch() will return immediately.

Anyway, special section indices rarely appear in these loops.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-28 20:35:16 +09:00
Masahiro Yamada
04ed3b4763 modpost: replace r->r_offset, r->r_addend with faddr, taddr
r_offset/r_addend holds the offset address from/to which a symbol is
referenced. It is unclear unless you are familiar with ELF.

Rename them to faddr, taddr, respectively. The prefix 'f' means 'from',
't' means 'to'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-28 20:34:40 +09:00
Masahiro Yamada
a23e7584ec modpost: unify 'sym' and 'to' in default_mismatch_handler()
find_tosym() takes 'sym' and stores the return value to another
variable 'to'. You can use the same variable because we want to
replace the original one when appropriate.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-28 20:34:05 +09:00
Masahiro Yamada
05bb070467 modpost: remove unused argument from secref_whitelist()
secref_whitelist() does not use the argument 'mismatch'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-28 20:32:04 +09:00
Masahiro Yamada
17b53f10ab Revert "modpost: skip ELF local symbols during section mismatch check"
This reverts commit a4d26f1a09.

The variable 'fromsym' never starts with ".L" since commit 87e5b1e8f2
("module: Sync code of is_arm_mapping_symbol()").

In other words, Pattern 6 is now dead code.

Previously, the .LANCHOR1 hid the symbols listed in Pattern 2.

87e5b1e8f2 provided a better solution.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-28 16:24:07 +09:00
Masahiro Yamada
ac263349b9 modpost: rename find_elf_symbol() and find_elf_symbol2()
find_elf_symbol() and find_elf_symbol2() are not good names.

Rename them to find_tosym(), find_fromsym(), respectively.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
9990ca3587 modpost: pass section index to find_elf_symbol2()
find_elf_symbol2() converts the section index to the section name,
then compares the two strings in each iteration. This is slow.

It is faster to compare the section indices (i.e. integers) directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
dbf7cc2e4e modpost: pass 'tosec' down to default_mismatch_handler()
default_mismatch_handler() does not need to compute 'tosec' because
it is calculated by the caller.

Pass it down to default_mismatch_handler() instead of calling
sec_name() twice.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
856567d559 modpost: squash extable_mismatch_handler() into default_mismatch_handler()
Merging these two reduces several lines of code. The extable section
mismatch is already distinguished by EXTABLE_TO_NON_TEXT.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
f4c35484e7 modpost: clean up is_executable_section()
SHF_EXECINSTR is a bit flag (#define SHF_EXECINSTR 0x4).
Compare the masked flag to '!= 0'.

There is no good reason to stop modpost immediately even if a special
section index is given. You will get a section mismatch error anyway.

Also, change the return type to bool.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
fc5fa862c4 modpost: squash report_sec_mismatch() into default_mismatch_handler()
report_sec_mismatch() and default_mismatch_handler() are small enough
to be merged together.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
faee9defd8 modpost: squash report_extable_warnings() into extable_mismatch_handler()
Collect relevant code into one place to clarify all the cases are
covered by 'if () ... else if ... else ...'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
6691e6f5fc modpost: remove get_prettyname()
This is the last user of get_pretty_name() - it is just used to
distinguish whether the symbol is a function or not. It is not
valuable information.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
6c90d36be3 modpost: remove fromsym info in __ex_table section mismatch warning
report_extable_warnings() prints "from" in a pretty form, but we know
it is always located in the __ex_table section, i.e. a collection of
struct exception_table_entry.

It is very likely to fail to get the symbol name and ends up with
meaningless message:

  ... in reference from the (unknown reference) (unknown) to ...

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
d0acc76a49 modpost: remove broken calculation of exception_table_entry size
find_extable_entry_size() is completely broken. It has awesome comments
about how to calculate sizeof(struct exception_table_entry).

It was based on these assumptions:

  - struct exception_table_entry has two fields
  - both of the fields have the same size

Then, we came up with this equation:

  (offset of the second field) * 2 == (size of struct)

It was true for all architectures when commit 52dc0595d5 ("modpost:
handle relocations mismatch in __ex_table.") was applied.

Our mathematics broke when commit 548acf1923 ("x86/mm: Expand the
exception table logic to allow new handling options") introduced the
third field.

Now, the definition of exception_table_entry is highly arch-dependent.

For x86, sizeof(struct exception_table_entry) is apparently 12, but
find_extable_entry_size() sets extable_entry_size to 8.

I could fix it, but I do not see much value in this code.

extable_entry_size is used just for selecting a slightly different
error message.

If the first field ("insn") references to a non-executable section,

    The relocation at %s+0x%lx references
    section "%s" which is not executable, IOW
    it is not possible for the kernel to fault
    at that address.  Something is seriously wrong
    and should be fixed.

If the second field ("fixup") references to a non-executable section,

    The relocation at %s+0x%lx references
    section "%s" which is not executable, IOW
    the kernel will fault if it ever tries to
    jump to it.  Something is seriously wrong
    and should be fixed.

Merge the two error messages rather than adding even more complexity.

Change fatal() to error() to make it continue running and catch more
possible errors.

Fixes: 548acf1923 ("x86/mm: Expand the exception table logic to allow new handling options")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-05-22 10:34:38 +09:00
Masahiro Yamada
64f140417d modpost: error out if addend_*_rel() is not implemented for REL arch
The section mismatch check relies on the relocation entries.

For REL, the addend value is implicit, so we need some code to compute
it. Currently, EM_386, EM_ARM, and EM_MIPS are supported. This commit
makes sure we covered all the cases.

I believe the other architectures use RELA, where the explicit r_addend
field exists.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-05-22 10:34:38 +09:00
Linus Torvalds
b6a7828502 modules-6.4-rc1
The summary of the changes for this pull requests is:
 
  * Song Liu's new struct module_memory replacement
  * Nick Alcock's MODULE_LICENSE() removal for non-modules
  * My cleanups and enhancements to reduce the areas where we vmalloc
    module memory for duplicates, and the respective debug code which
    proves the remaining vmalloc pressure comes from userspace.
 
 Most of the changes have been in linux-next for quite some time except
 the minor fixes I made to check if a module was already loaded
 prior to allocating the final module memory with vmalloc and the
 respective debug code it introduces to help clarify the issue. Although
 the functional change is small it is rather safe as it can only *help*
 reduce vmalloc space for duplicates and is confirmed to fix a bootup
 issue with over 400 CPUs with KASAN enabled. I don't expect stable
 kernels to pick up that fix as the cleanups would have also had to have
 been picked up. Folks on larger CPU systems with modules will want to
 just upgrade if vmalloc space has been an issue on bootup.
 
 Given the size of this request, here's some more elaborate details
 on this pull request.
 
 The functional change change in this pull request is the very first
 patch from Song Liu which replaces the struct module_layout with a new
 struct module memory. The old data structure tried to put together all
 types of supported module memory types in one data structure, the new
 one abstracts the differences in memory types in a module to allow each
 one to provide their own set of details. This paves the way in the
 future so we can deal with them in a cleaner way. If you look at changes
 they also provide a nice cleanup of how we handle these different memory
 areas in a module. This change has been in linux-next since before the
 merge window opened for v6.3 so to provide more than a full kernel cycle
 of testing. It's a good thing as quite a bit of fixes have been found
 for it.
 
 Jason Baron then made dynamic debug a first class citizen module user by
 using module notifier callbacks to allocate / remove module specific
 dynamic debug information.
 
 Nick Alcock has done quite a bit of work cross-tree to remove module
 license tags from things which cannot possibly be module at my request
 so to:
 
   a) help him with his longer term tooling goals which require a
      deterministic evaluation if a piece a symbol code could ever be
      part of a module or not. But quite recently it is has been made
      clear that tooling is not the only one that would benefit.
      Disambiguating symbols also helps efforts such as live patching,
      kprobes and BPF, but for other reasons and R&D on this area
      is active with no clear solution in sight.
 
   b) help us inch closer to the now generally accepted long term goal
      of automating all the MODULE_LICENSE() tags from SPDX license tags
 
 In so far as a) is concerned, although module license tags are a no-op
 for non-modules, tools which would want create a mapping of possible
 modules can only rely on the module license tag after the commit
 8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
 or tristate.conf").  Nick has been working on this *for years* and
 AFAICT I was the only one to suggest two alternatives to this approach
 for tooling. The complexity in one of my suggested approaches lies in
 that we'd need a possible-obj-m and a could-be-module which would check
 if the object being built is part of any kconfig build which could ever
 lead to it being part of a module, and if so define a new define
 -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
 suggested would be to have a tristate in kconfig imply the same new
 -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
 mapping to modules always, and I don't think that's the case today. I am
 not aware of Nick or anyone exploring either of these options. Quite
 recently Josh Poimboeuf has pointed out that live patching, kprobes and
 BPF would benefit from resolving some part of the disambiguation as
 well but for other reasons. The function granularity KASLR (fgkaslr)
 patches were mentioned but Joe Lawrence has clarified this effort has
 been dropped with no clear solution in sight [1].
 
 In the meantime removing module license tags from code which could never
 be modules is welcomed for both objectives mentioned above. Some
 developers have also welcomed these changes as it has helped clarify
 when a module was never possible and they forgot to clean this up,
 and so you'll see quite a bit of Nick's patches in other pull
 requests for this merge window. I just picked up the stragglers after
 rc3. LWN has good coverage on the motivation behind this work [2] and
 the typical cross-tree issues he ran into along the way. The only
 concrete blocker issue he ran into was that we should not remove the
 MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
 they can never be modules. Nick ended up giving up on his efforts due
 to having to do this vetting and backlash he ran into from folks who
 really did *not understand* the core of the issue nor were providing
 any alternative / guidance. I've gone through his changes and dropped
 the patches which dropped the module license tags where an SPDX
 license tag was missing, it only consisted of 11 drivers.  To see
 if a pull request deals with a file which lacks SPDX tags you
 can just use:
 
   ./scripts/spdxcheck.py -f \
 	$(git diff --name-only commid-id | xargs echo)
 
 You'll see a core module file in this pull request for the above,
 but that's not related to his changes. WE just need to add the SPDX
 license tag for the kernel/module/kmod.c file in the future but
 it demonstrates the effectiveness of the script.
 
 Most of Nick's changes were spread out through different trees,
 and I just picked up the slack after rc3 for the last kernel was out.
 Those changes have been in linux-next for over two weeks.
 
 The cleanups, debug code I added and final fix I added for modules
 were motivated by David Hildenbrand's report of boot failing on
 a systems with over 400 CPUs when KASAN was enabled due to running
 out of virtual memory space. Although the functional change only
 consists of 3 lines in the patch "module: avoid allocation if module is
 already present and ready", proving that this was the best we can
 do on the modules side took quite a bit of effort and new debug code.
 
 The initial cleanups I did on the modules side of things has been
 in linux-next since around rc3 of the last kernel, the actual final
 fix for and debug code however have only been in linux-next for about a
 week or so but I think it is worth getting that code in for this merge
 window as it does help fix / prove / evaluate the issues reported
 with larger number of CPUs. Userspace is not yet fixed as it is taking
 a bit of time for folks to understand the crux of the issue and find a
 proper resolution. Worst come to worst, I have a kludge-of-concept [3]
 of how to make kernel_read*() calls for modules unique / converge them,
 but I'm currently inclined to just see if userspace can fix this
 instead.
 
 [0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
 [1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
 [2] https://lwn.net/Articles/927569/
 [3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
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Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull module updates from Luis Chamberlain:
 "The summary of the changes for this pull requests is:

   - Song Liu's new struct module_memory replacement

   - Nick Alcock's MODULE_LICENSE() removal for non-modules

   - My cleanups and enhancements to reduce the areas where we vmalloc
     module memory for duplicates, and the respective debug code which
     proves the remaining vmalloc pressure comes from userspace.

  Most of the changes have been in linux-next for quite some time except
  the minor fixes I made to check if a module was already loaded prior
  to allocating the final module memory with vmalloc and the respective
  debug code it introduces to help clarify the issue. Although the
  functional change is small it is rather safe as it can only *help*
  reduce vmalloc space for duplicates and is confirmed to fix a bootup
  issue with over 400 CPUs with KASAN enabled. I don't expect stable
  kernels to pick up that fix as the cleanups would have also had to
  have been picked up. Folks on larger CPU systems with modules will
  want to just upgrade if vmalloc space has been an issue on bootup.

  Given the size of this request, here's some more elaborate details:

  The functional change change in this pull request is the very first
  patch from Song Liu which replaces the 'struct module_layout' with a
  new 'struct module_memory'. The old data structure tried to put
  together all types of supported module memory types in one data
  structure, the new one abstracts the differences in memory types in a
  module to allow each one to provide their own set of details. This
  paves the way in the future so we can deal with them in a cleaner way.
  If you look at changes they also provide a nice cleanup of how we
  handle these different memory areas in a module. This change has been
  in linux-next since before the merge window opened for v6.3 so to
  provide more than a full kernel cycle of testing. It's a good thing as
  quite a bit of fixes have been found for it.

  Jason Baron then made dynamic debug a first class citizen module user
  by using module notifier callbacks to allocate / remove module
  specific dynamic debug information.

  Nick Alcock has done quite a bit of work cross-tree to remove module
  license tags from things which cannot possibly be module at my request
  so to:

   a) help him with his longer term tooling goals which require a
      deterministic evaluation if a piece a symbol code could ever be
      part of a module or not. But quite recently it is has been made
      clear that tooling is not the only one that would benefit.
      Disambiguating symbols also helps efforts such as live patching,
      kprobes and BPF, but for other reasons and R&D on this area is
      active with no clear solution in sight.

   b) help us inch closer to the now generally accepted long term goal
      of automating all the MODULE_LICENSE() tags from SPDX license tags

  In so far as a) is concerned, although module license tags are a no-op
  for non-modules, tools which would want create a mapping of possible
  modules can only rely on the module license tag after the commit
  8b41fc4454 ("kbuild: create modules.builtin without
  Makefile.modbuiltin or tristate.conf").

  Nick has been working on this *for years* and AFAICT I was the only
  one to suggest two alternatives to this approach for tooling. The
  complexity in one of my suggested approaches lies in that we'd need a
  possible-obj-m and a could-be-module which would check if the object
  being built is part of any kconfig build which could ever lead to it
  being part of a module, and if so define a new define
  -DPOSSIBLE_MODULE [0].

  A more obvious yet theoretical approach I've suggested would be to
  have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
  well but that means getting kconfig symbol names mapping to modules
  always, and I don't think that's the case today. I am not aware of
  Nick or anyone exploring either of these options. Quite recently Josh
  Poimboeuf has pointed out that live patching, kprobes and BPF would
  benefit from resolving some part of the disambiguation as well but for
  other reasons. The function granularity KASLR (fgkaslr) patches were
  mentioned but Joe Lawrence has clarified this effort has been dropped
  with no clear solution in sight [1].

  In the meantime removing module license tags from code which could
  never be modules is welcomed for both objectives mentioned above. Some
  developers have also welcomed these changes as it has helped clarify
  when a module was never possible and they forgot to clean this up, and
  so you'll see quite a bit of Nick's patches in other pull requests for
  this merge window. I just picked up the stragglers after rc3. LWN has
  good coverage on the motivation behind this work [2] and the typical
  cross-tree issues he ran into along the way. The only concrete blocker
  issue he ran into was that we should not remove the MODULE_LICENSE()
  tags from files which have no SPDX tags yet, even if they can never be
  modules. Nick ended up giving up on his efforts due to having to do
  this vetting and backlash he ran into from folks who really did *not
  understand* the core of the issue nor were providing any alternative /
  guidance. I've gone through his changes and dropped the patches which
  dropped the module license tags where an SPDX license tag was missing,
  it only consisted of 11 drivers. To see if a pull request deals with a
  file which lacks SPDX tags you can just use:

    ./scripts/spdxcheck.py -f \
	$(git diff --name-only commid-id | xargs echo)

  You'll see a core module file in this pull request for the above, but
  that's not related to his changes. WE just need to add the SPDX
  license tag for the kernel/module/kmod.c file in the future but it
  demonstrates the effectiveness of the script.

  Most of Nick's changes were spread out through different trees, and I
  just picked up the slack after rc3 for the last kernel was out. Those
  changes have been in linux-next for over two weeks.

  The cleanups, debug code I added and final fix I added for modules
  were motivated by David Hildenbrand's report of boot failing on a
  systems with over 400 CPUs when KASAN was enabled due to running out
  of virtual memory space. Although the functional change only consists
  of 3 lines in the patch "module: avoid allocation if module is already
  present and ready", proving that this was the best we can do on the
  modules side took quite a bit of effort and new debug code.

  The initial cleanups I did on the modules side of things has been in
  linux-next since around rc3 of the last kernel, the actual final fix
  for and debug code however have only been in linux-next for about a
  week or so but I think it is worth getting that code in for this merge
  window as it does help fix / prove / evaluate the issues reported with
  larger number of CPUs. Userspace is not yet fixed as it is taking a
  bit of time for folks to understand the crux of the issue and find a
  proper resolution. Worst come to worst, I have a kludge-of-concept [3]
  of how to make kernel_read*() calls for modules unique / converge
  them, but I'm currently inclined to just see if userspace can fix this
  instead"

Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]

* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
  module: add debugging auto-load duplicate module support
  module: stats: fix invalid_mod_bytes typo
  module: remove use of uninitialized variable len
  module: fix building stats for 32-bit targets
  module: stats: include uapi/linux/module.h
  module: avoid allocation if module is already present and ready
  module: add debug stats to help identify memory pressure
  module: extract patient module check into helper
  modules/kmod: replace implementation with a semaphore
  Change DEFINE_SEMAPHORE() to take a number argument
  module: fix kmemleak annotations for non init ELF sections
  module: Ignore L0 and rename is_arm_mapping_symbol()
  module: Move is_arm_mapping_symbol() to module_symbol.h
  module: Sync code of is_arm_mapping_symbol()
  scripts/gdb: use mem instead of core_layout to get the module address
  interconnect: remove module-related code
  interconnect: remove MODULE_LICENSE in non-modules
  zswap: remove MODULE_LICENSE in non-modules
  zpool: remove MODULE_LICENSE in non-modules
  x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
  ...
2023-04-27 16:36:55 -07:00
Tiezhu Yang
0a3bf86092 module: Ignore L0 and rename is_arm_mapping_symbol()
The L0 symbol is generated when build module on LoongArch, ignore it in
modpost and when looking at module symbols, otherwise we can not see the
expected call trace.

Now is_arm_mapping_symbol() is not only for ARM, in order to reflect the
reality, rename is_arm_mapping_symbol() to is_mapping_symbol().

This is related with commit c17a253870 ("mksysmap: Fix the mismatch of
'L0' symbols in System.map").

(1) Simple test case

  [loongson@linux hello]$ cat hello.c
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/printk.h>

  static void test_func(void)
  {
  	  pr_info("This is a test\n");
	  dump_stack();
  }

  static int __init hello_init(void)
  {
	  pr_warn("Hello, world\n");
	  test_func();

	  return 0;
  }

  static void __exit hello_exit(void)
  {
	  pr_warn("Goodbye\n");
  }

  module_init(hello_init);
  module_exit(hello_exit);
  MODULE_LICENSE("GPL");
  [loongson@linux hello]$ cat Makefile
  obj-m:=hello.o

  ccflags-y += -g -Og

  all:
	  make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
  clean:
	  make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) clean

(2) Test environment

system: LoongArch CLFS 5.5
https://github.com/sunhaiyong1978/CLFS-for-LoongArch/releases/tag/5.0
It needs to update grub to avoid booting error "invalid magic number".

kernel: 6.3-rc1 with loongson3_defconfig + CONFIG_DYNAMIC_FTRACE=y

(3) Test result

Without this patch:

  [root@linux hello]# insmod hello.ko
  [root@linux hello]# dmesg
  ...
  Hello, world
  This is a test
  ...
  Call Trace:
  [<9000000000223728>] show_stack+0x68/0x18c
  [<90000000013374cc>] dump_stack_lvl+0x60/0x88
  [<ffff800002050028>] L0\x01+0x20/0x2c [hello]
  [<ffff800002058028>] L0\x01+0x20/0x30 [hello]
  [<900000000022097c>] do_one_initcall+0x88/0x288
  [<90000000002df890>] do_init_module+0x54/0x200
  [<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114
  [<90000000013382e8>] do_syscall+0x7c/0x94
  [<9000000000221e3c>] handle_syscall+0xbc/0x158

With this patch:

  [root@linux hello]# insmod hello.ko
  [root@linux hello]# dmesg
  ...
  Hello, world
  This is a test
  ...
  Call Trace:
  [<9000000000223728>] show_stack+0x68/0x18c
  [<90000000013374cc>] dump_stack_lvl+0x60/0x88
  [<ffff800002050028>] test_func+0x28/0x34 [hello]
  [<ffff800002058028>] hello_init+0x28/0x38 [hello]
  [<900000000022097c>] do_one_initcall+0x88/0x288
  [<90000000002df890>] do_init_module+0x54/0x200
  [<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114
  [<90000000013382e8>] do_syscall+0x7c/0x94
  [<9000000000221e3c>] handle_syscall+0xbc/0x158

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Youling Tang <tangyouling@loongson.cn> # for LoongArch
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 17:15:50 -07:00
Tiezhu Yang
987d2e0aaa module: Move is_arm_mapping_symbol() to module_symbol.h
In order to avoid duplicated code, move is_arm_mapping_symbol() to
include/linux/module_symbol.h, then remove is_arm_mapping_symbol()
in the other places.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 17:15:49 -07:00
Tiezhu Yang
87e5b1e8f2 module: Sync code of is_arm_mapping_symbol()
After commit 2e3a10a155 ("ARM: avoid ARM binutils leaking ELF local
symbols") and commit d6b732666a ("modpost: fix undefined behavior of
is_arm_mapping_symbol()"), many differences of is_arm_mapping_symbol()
exist in kernel/module/kallsyms.c and scripts/mod/modpost.c, just sync
the code to keep consistent.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 17:15:49 -07:00
Greg Kroah-Hartman
5790d407da Merge 6.3-rc6 into char-misc-next
We need it here to apply other char/misc driver changes to.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-10 08:49:26 +02:00
Nipun Gupta
2959ab2470 cdx: add the cdx bus driver
Introduce AMD CDX bus, which provides a mechanism for scanning
and probing CDX devices. These devices are memory mapped on
system bus for Application Processors(APUs).

CDX devices can be changed dynamically in the Fabric and CDX
bus interacts with CDX controller to rescan the bus and
rediscover the devices.

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20230313132636.31850-2-nipun.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 12:26:32 +02:00
Ben Hutchings
fb27e70f6e modpost: Fix processing of CRCs on 32-bit build machines
modpost now reads CRCs from .*.cmd files, parsing them using strtol().
This is inconsistent with its parsing of Module.symvers and with their
definition as *unsigned* 32-bit values.

strtol() clamps values to [LONG_MIN, LONG_MAX], and when building on a
32-bit system this changes all CRCs >= 0x80000000 to be 0x7fffffff.

Change extract_crcs_for_object() to use strtoul() instead.

Cc: stable@vger.kernel.org
Fixes: f292d875d0 ("modpost: extract symbol versions from *.cmd files")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-03-23 15:28:41 +09:00
Linus Torvalds
6feb57c2fd Kbuild updates for v6.2
- Support zstd-compressed debug info
 
  - Allow W=1 builds to detect objects shared among multiple modules
 
  - Add srcrpm-pkg target to generate a source RPM package
 
  - Make the -s option detection work for future GNU Make versions
 
  - Add -Werror to KBUILD_CPPFLAGS when CONFIG_WERROR=y
 
  - Allow W=1 builds to detect -Wundef warnings in any preprocessed files
 
  - Raise the minimum supported version of binutils to 2.25
 
  - Use $(intcmp ...) to compare integers if GNU Make >= 4.4 is used
 
  - Use $(file ...) to read a file if GNU Make >= 4.2 is used
 
  - Print error if GNU Make older than 3.82 is used
 
  - Allow modpost to detect section mismatches with Clang LTO
 
  - Include vmlinuz.efi into kernel tarballs for arm64 CONFIG_EFI_ZBOOT=y
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Merge tag 'kbuild-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support zstd-compressed debug info

 - Allow W=1 builds to detect objects shared among multiple modules

 - Add srcrpm-pkg target to generate a source RPM package

 - Make the -s option detection work for future GNU Make versions

 - Add -Werror to KBUILD_CPPFLAGS when CONFIG_WERROR=y

 - Allow W=1 builds to detect -Wundef warnings in any preprocessed files

 - Raise the minimum supported version of binutils to 2.25

 - Use $(intcmp ...) to compare integers if GNU Make >= 4.4 is used

 - Use $(file ...) to read a file if GNU Make >= 4.2 is used

 - Print error if GNU Make older than 3.82 is used

 - Allow modpost to detect section mismatches with Clang LTO

 - Include vmlinuz.efi into kernel tarballs for arm64 CONFIG_EFI_ZBOOT=y

* tag 'kbuild-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
  buildtar: fix tarballs with EFI_ZBOOT enabled
  modpost: Include '.text.*' in TEXT_SECTIONS
  padata: Mark padata_work_init() as __ref
  kbuild: ensure Make >= 3.82 is used
  kbuild: refactor the prerequisites of the modpost rule
  kbuild: change module.order to list *.o instead of *.ko
  kbuild: use .NOTINTERMEDIATE for future GNU Make versions
  kconfig: refactor Makefile to reduce process forks
  kbuild: add read-file macro
  kbuild: do not sort after reading modules.order
  kbuild: add test-{ge,gt,le,lt} macros
  Documentation: raise minimum supported version of binutils to 2.25
  kbuild: add -Wundef to KBUILD_CPPFLAGS for W=1 builds
  kbuild: move -Werror from KBUILD_CFLAGS to KBUILD_CPPFLAGS
  kbuild: Port silent mode detection to future gnu make.
  init/version.c: remove #include <generated/utsrelease.h>
  firmware_loader: remove #include <generated/utsrelease.h>
  modpost: Mark uuid_le type to be suitable only for MEI
  kbuild: add ability to make source rpm buildable using koji
  kbuild: warn objects shared among multiple modules
  ...
2022-12-19 12:33:32 -06:00
Nathan Chancellor
19331e84c3 modpost: Include '.text.*' in TEXT_SECTIONS
Commit 6c730bfc89 ("modpost: handle -ffunction-sections") added
".text.*" to the OTHER_TEXT_SECTIONS macro to fix certain section
mismatch warnings. Unfortunately, this makes it impossible for modpost
to warn about section mismatches with LTO, which implies
'-ffunction-sections', as all functions are put in their own
'.text.<func_name>' sections, which may still reference functions in
sections they are not supposed to, such as __init.

Fix this by moving ".text.*" into TEXT_SECTIONS, so that configurations
with '-ffunction-sections' will see warnings about mismatched sections.

Link: https://lore.kernel.org/Y39kI3MOtVI5BAnV@google.com/
Reported-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-and-tested-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-12-14 15:49:34 +09:00
Masahiro Yamada
f65a486821 kbuild: change module.order to list *.o instead of *.ko
scripts/Makefile.build replaces the suffix .o with .ko, then
scripts/Makefile.modpost calls the sed command to change .ko back
to the original .o suffix.

Instead of converting the suffixes back-and-forth, store the .o paths
in modules.order, and replace it with .ko in 'make modules_install'.

This avoids the unneeded sed command.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
2022-12-14 15:42:40 +09:00
Youling Tang
3d36f4298b LoongArch: Switch to relative exception tables
Similar to other architectures such as arm64, x86, riscv and so on, use
offsets relative to the exception table entry values rather than their
absolute addresses for both the exception location and the fixup.

However, LoongArch label difference because it will actually produce two
relocations, a pair of R_LARCH_ADD32 and R_LARCH_SUB32. Take simple code
below for example:

$ cat test_ex_table.S
.section .text
1:
        nop
.section __ex_table,"a"
        .balign 4
        .long (1b - .)
.previous

$ loongarch64-unknown-linux-gnu-gcc -c test_ex_table.S
$ loongarch64-unknown-linux-gnu-readelf -Wr test_ex_table.o

Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries:
    Offset            Info             Type         Symbol's Value   Symbol's Name + Addend
0000000000000000 0000000600000032 R_LARCH_ADD32    0000000000000000  .L1^B1 + 0
0000000000000000 0000000500000037 R_LARCH_SUB32    0000000000000000  L0^A + 0

The modpost will complain the R_LARCH_SUB32 relocation, so we need to
patch modpost.c to skip this relocation for .rela__ex_table section.

Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14 08:36:11 +08:00
Andy Shevchenko
248043299b modpost: Mark uuid_le type to be suitable only for MEI
The uuid_le type is used only in MEI ABI, do not advertise it for others.
While at it, comment out that UUID types are not to be used in a new code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2022-11-27 08:08:16 +09:00
KaiLong Wang
30daacc571 modpost: fix array_size.cocci warning
Fix following coccicheck warning:

scripts/mod/sumversion.c:219:48-49: WARNING: Use ARRAY_SIZE
scripts/mod/sumversion.c:156:48-49: WARNING: Use ARRAY_SIZE

Signed-off-by: KaiLong Wang <wangkailong@jari.cn>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-11-21 10:18:39 +09:00
Geert Uytterhoeven
0d2573a2b7 modpost: Join broken long printed messages
Breaking long printed messages in multiple lines makes it very hard to
look up where they originated from.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-11-21 10:18:39 +09:00
Masahiro Yamada
5b8a9a8fd1 modpost: fix module versioning when a symbol lacks valid CRC
Since commit 7b4537199a ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), module versioning is broken on
some architectures. Loading a module fails with "disagrees about
version of symbol module_layout".

On such architectures (e.g. ARCH=sparc build with sparc64_defconfig),
modpost shows a warning, like follows:

  WARNING: modpost: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.
  Is "_mcount" prototyped in <asm/asm-prototypes.h>?

Previously, it was a harmless warning (CRC check was just skipped),
but now wrong CRCs are used for comparison because invalid CRCs are
just skipped.

  $ sparc64-linux-gnu-nm -n vmlinux
    [snip]
  0000000000c2cea0 r __ksymtab__kstrtol
  0000000000c2ceb8 r __ksymtab__kstrtoul
  0000000000c2ced0 r __ksymtab__local_bh_enable
  0000000000c2cee8 r __ksymtab__mcount
  0000000000c2cf00 r __ksymtab__printk
  0000000000c2cf18 r __ksymtab__raw_read_lock
  0000000000c2cf30 r __ksymtab__raw_read_lock_bh
    [snip]
  0000000000c53b34 D __crc__kstrtol
  0000000000c53b38 D __crc__kstrtoul
  0000000000c53b3c D __crc__local_bh_enable
  0000000000c53b40 D __crc__printk
  0000000000c53b44 D __crc__raw_read_lock
  0000000000c53b48 D __crc__raw_read_lock_bh

Please notice __crc__mcount is missing here.

When the module subsystem looks up a CRC that comes after, it results
in reading out a wrong address. For example, when __crc__printk is
needed, the module subsystem reads 0xc53b44 instead of 0xc53b40.

All CRC entries must be output for correct index accessing. Invalid
CRCs will be unused, but are needed to keep the one-to-one mapping
between __ksymtab_* and __crc_*.

The best is to fix all modpost warnings, but several warnings are still
remaining on less popular architectures.

Fixes: 7b4537199a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS")
Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: matoro <matoro_mailinglist_kernel@matoro.tk>
2022-08-21 02:47:36 +09:00
Linus Torvalds
0af5cb349a Kbuild updates for v5.20
- Remove the support for -O3 (CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3)
 
  - Fix error of rpm-pkg cross-builds
 
  - Support riscv for checkstack tool
 
  - Re-enable -Wformwat warnings for Clang
 
  - Clean up modpost, Makefiles, and misc scripts
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Merge tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Remove the support for -O3 (CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3)

 - Fix error of rpm-pkg cross-builds

 - Support riscv for checkstack tool

 - Re-enable -Wformwat warnings for Clang

 - Clean up modpost, Makefiles, and misc scripts

* tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
  modpost: remove .symbol_white_list field entirely
  modpost: remove unneeded .symbol_white_list initializers
  modpost: add PATTERNS() helper macro
  modpost: shorten warning messages in report_sec_mismatch()
  Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost"
  modpost: use more reliable way to get fromsec in section_rel(a)()
  modpost: add array range check to sec_name()
  modpost: refactor get_secindex()
  kbuild: set EXIT trap before creating temporary directory
  modpost: remove unused Elf_Sword macro
  Makefile.extrawarn: re-enable -Wformat for clang
  kbuild: add dtbs_prepare target
  kconfig: Qt5: tell the user which packages are required
  modpost: use sym_get_data() to get module device_table data
  modpost: drop executable ELF support
  checkstack: add riscv support for scripts/checkstack.pl
  kconfig: shorten the temporary directory name for cc-option
  scripts: headers_install.sh: Update config leak ignore entries
  kbuild: error out if $(INSTALL_MOD_PATH) contains % or :
  kbuild: error out if $(KBUILD_EXTMOD) contains % or :
  ...
2022-08-10 10:40:41 -07:00
Masahiro Yamada
672fb6740c modpost: remove .symbol_white_list field entirely
It is not so useful to have symbol whitelists in arrays. With this
over-engineering, the code is difficult to follow.

Let's do it more directly, and collect the relevant code to one place.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-04 20:32:13 +09:00
Masahiro Yamada
1560cb0e18 modpost: remove unneeded .symbol_white_list initializers
The ->symbol_white_list field is referenced in secref_whitelist(),
only when 'fromsec' is data_sections.

        /* Check for pattern 2 */
        if (match(tosec, init_exit_sections) &&
            match(fromsec, data_sections) &&
            match(fromsym, mismatch->symbol_white_list))
                return 0;

If .fromsec is not data sections, the .symbol_white_list member is
not used by anyone.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-04 20:32:13 +09:00
Masahiro Yamada
7452dd26a5 modpost: add PATTERNS() helper macro
This will be useful to define a NULL-terminated array inside a function
call.

Currently, string arrays passed to match() are defined in separate
places:

    static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
    static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
    static const char *const optim_symbols[] = { "*.constprop.*", NULL };

            ...

            /* Check for pattern 5 */
            if (match(fromsec, text_sections) &&
                match(tosec, init_sections) &&
                match(fromsym, optim_symbols))
                    return 0;

With the new helper macro, you can list the patterns directly in the
function call, like this:

            /* Check for pattern 5 */
            if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
                match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
                match(fromsym, PATTERNS("*.contprop.*")))
                    return 0;

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-04 20:32:13 +09:00
Masahiro Yamada
072dd2c892 modpost: shorten warning messages in report_sec_mismatch()
Each section mismatch results in long warning messages. Too much.

Make each warning fit in one line, and remove a lot of messy code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-04 20:32:13 +09:00
Masahiro Yamada
a25efd6ef1 Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost"
This reverts commit 77ab21adae.

Even after 8 years later, GCC LTO has not been upstreamed. Also, it said
"This is a workaround". If this is needed in the future, it should be
added in a proper way.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
2022-08-04 20:27:17 +09:00
Masahiro Yamada
5419aa2a8d modpost: use more reliable way to get fromsec in section_rel(a)()
The section name of Rel and Rela starts with ".rel" and ".rela"
respectively (but, I do not know whether this is specification or
convention).

For example, ".rela.text" holds relocation entries applied to the
".text" section.

So, the code chops the ".rel" or ".rela" prefix to get the name of
the section to which the relocation applies.

However, I do not like to skip 4 or 5 bytes blindly because it is
potential memory overrun.

The ELF specification provides a more reliable way to do this.

 - The sh_info field holds extra information, whose interpretation
   depends on the section type

 - If the section type is SHT_REL or SHT_RELA, the sh_info field holds
   the section header index of the section to which the relocation
   applies.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-03 22:58:10 +09:00
Masahiro Yamada
125ed24a4a modpost: add array range check to sec_name()
The section index is always positive, so the argument, secindex, should
be unsigned.

Also, inserted the array range check.

If sym->st_shndx is a special section index (between SHN_LORESERVE and
SHN_HIRESERVE), there is no corresponding section header.

For example, if a symbol specifies an absolute value, sym->st_shndx is
SHN_ABS (=0xfff1).

The current users do not cause the out-of-range access of
info->sechddrs[], but it is better to avoid such a pitfall.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-03 22:58:10 +09:00
Masahiro Yamada
36b0f0deed modpost: refactor get_secindex()
SPECIAL() is only used in get_secindex(). Squash it.

Make the code more readable with more comments.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-03 22:56:46 +09:00
Masahiro Yamada
7193cda917 modpost: remove unused Elf_Sword macro
Commit 9ad21c3f3e ("kbuild: try harder to find symbol names in
modpost") added Elf_Sword (in a wrong way), but did not use it at all.

BTW, the current code looks weird.

The fix for the 32-bit part would be:

    Elf64_Sword  -->  Elf32_Sword

(inconsistet prefix, Elf32_ vs Elf64_)

The fix for the 64-bit part would be:

    Elf64_Sxword  -->  Elf64_Sword

(the size is different between Sword and Sxword)

Note:

    Elf32_Sword   ==  Elf64_Sword   ==  int32_t
    Elf32_Sxword  ==  Elf64_Sxword  ==  int64_t

Anyway, let's drop unused code instead of fixing it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-08-03 19:37:59 +09:00
Linus Torvalds
665fe72a7d linux-kselftest-kunit-5.20-rc1
This KUnit update for Linux 5.20-rc1 consists of several fixes and an
 important feature to discourage running KUnit tests on production
 systems. Running tests on a production system could leave the system
 in a bad state. This new feature adds:
 
 - adds a new taint type, TAINT_TEST to signal that a test has been run.
   This should discourage people from running these tests on production
   systems, and to make it easier to tell if tests have been run
   accidentally (by loading the wrong configuration, etc.)
 
 - several documentation and tool enhancements and fixes.
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Merge tag 'linux-kselftest-kunit-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:
 "This consists of several fixes and an important feature to discourage
  running KUnit tests on production systems. Running tests on a
  production system could leave the system in a bad state.

  Summary:

   - Add a new taint type, TAINT_TEST to signal that a test has been
     run.

     This should discourage people from running these tests on
     production systems, and to make it easier to tell if tests have
     been run accidentally (by loading the wrong configuration, etc)

   - Several documentation and tool enhancements and fixes"

* tag 'linux-kselftest-kunit-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
  Documentation: KUnit: Fix example with compilation error
  Documentation: kunit: Add CLI args for kunit_tool
  kcsan: test: Add a .kunitconfig to run KCSAN tests
  kunit: executor: Fix a memory leak on failure in kunit_filter_tests
  clk: explicitly disable CONFIG_UML_PCI_OVER_VIRTIO in .kunitconfig
  mmc: sdhci-of-aspeed: test: Use kunit_test_suite() macro
  nitro_enclaves: test: Use kunit_test_suite() macro
  thunderbolt: test: Use kunit_test_suite() macro
  kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites
  kunit: unify module and builtin suite definitions
  selftest: Taint kernel when test module loaded
  module: panic: Taint the kernel when selftest modules load
  Documentation: kunit: fix example run_kunit func to allow spaces in args
  Documentation: kunit: Cleanup run_wrapper, fix x-ref
  kunit: test.h: fix a kernel-doc markup
  kunit: tool: Enable virtio/PCI by default on UML
  kunit: tool: make --kunitconfig repeatable, blindly concat
  kunit: add coverage_uml.config to enable GCOV on UML
  kunit: tool: refactor internal kconfig handling, allow overriding
  kunit: tool: introduce --qemu_args
  ...
2022-08-02 19:34:45 -07:00
Masahiro Yamada
abe864b8e1 modpost: use sym_get_data() to get module device_table data
Use sym_get_data() to replace the long code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-07-27 21:18:00 +09:00
Masahiro Yamada
5764f6626f modpost: drop executable ELF support
Since commit 269a535ca9 ("modpost: generate vmlinux.symvers and
reuse it for the second modpost"), modpost only parses relocatable
files (ET_REL).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-07-27 21:18:00 +09:00
Masahiro Yamada
028062ec22 Revert "scripts/mod/modpost.c: permit '.cranges' secton for sh64 architecture."
This reverts commit 4d10c223ba.

Commit 37744feebc ("sh: remove sh5 support") removed the sh64 support
entirely.

Note:
.cranges was only used for sh64 ever.
Commit 211dc24b8744 ("Remove sh5 and sh64 support") in binutils-gdb
already removed the relevant code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-07-27 21:17:59 +09:00
David Gow
74829ddf59 module: panic: Taint the kernel when selftest modules load
Taint the kernel with TAINT_TEST whenever a test module loads, by adding
a new "TEST" module property, and setting it for all modules in the
tools/testing directory. This property can also be set manually, for
tests which live outside the tools/testing directory with:
MODULE_INFO(test, "Y");

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-07-11 16:58:00 -06:00
Masahiro Yamada
28438794ab modpost: fix section mismatch check for exported init/exit sections
Since commit f02e8a6596 ("module: Sort exported symbols"),
EXPORT_SYMBOL* is placed in the individual section ___ksymtab(_gpl)+<sym>
(3 leading underscores instead of 2).

Since then, modpost cannot detect the bad combination of EXPORT_SYMBOL
and __init/__exit.

Fix the .fromsec field.

Fixes: f02e8a6596 ("module: Sort exported symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-06-20 08:18:03 +09:00
Linus Torvalds
71e80720db Kbuild updates for v5.19 (2nd)
- Fix build regressions for parisc, csky, nios2, openrisc
 
  - Simplify module builds for CONFIG_LTO_CLANG and CONFIG_X86_KERNEL_IBT
 
  - Remove arch/parisc/nm, which was presumably a workaround for old tools
 
  - Check the odd combination of EXPORT_SYMBOL and 'static' precisely
 
  - Make external module builds robust against "too long argument error"
 
  - Support j, k keys for moving the cursor in nconfig
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Merge tag 'kbuild-v5.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:

 - Fix build regressions for parisc, csky, nios2, openrisc

 - Simplify module builds for CONFIG_LTO_CLANG and CONFIG_X86_KERNEL_IBT

 - Remove arch/parisc/nm, which was presumably a workaround for old
   tools

 - Check the odd combination of EXPORT_SYMBOL and 'static' precisely

 - Make external module builds robust against "too long argument error"

 - Support j, k keys for moving the cursor in nconfig

* tag 'kbuild-v5.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
  kbuild: Allow to select bash in a modified environment
  scripts: kconfig: nconf: make nconfig accept jk keybindings
  modpost: use fnmatch() to simplify match()
  modpost: simplify mod->name allocation
  kbuild: factor out the common objtool arguments
  kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o
  kbuild: clean .tmp_* pattern by make clean
  kbuild: remove redundant cleanups in scripts/link-vmlinux.sh
  kbuild: rebuild multi-object modules when objtool is updated
  kbuild: add cmd_and_savecmd macro
  kbuild: make *.mod rule robust against too long argument error
  kbuild: make built-in.a rule robust against too long argument error
  kbuild: check static EXPORT_SYMBOL* by script instead of modpost
  parisc: remove arch/parisc/nm
  kbuild: do not create *.prelink.o for Clang LTO or IBT
  kbuild: replace $(linked-object) with CONFIG options
  kbuild: do not try to parse *.cmd files for objects provided by compiler
  kbuild: replace $(if A,A,B) with $(or A,B) in scripts/Makefile.modpost
  modpost: squash if...else-if in find_elf_symbol2()
  modpost: reuse ARRAY_SIZE() macro for section_mismatch()
  ...
2022-06-05 09:06:03 -07:00
Masahiro Yamada
a89227d769 modpost: use fnmatch() to simplify match()
Replace the own implementation for wildcard (glob) matching with
a function call to fnmatch().

Also, change the return type to 'bool'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-06-05 06:20:57 +09:00
Masahiro Yamada
8c9ce89c5b modpost: simplify mod->name allocation
mod->name is set to the ELF filename with the suffix ".o" stripped.

The current code calls strdup() and free() to manipulate the string,
but a simpler approach is to pass new_module() with the name length
subtracted by 2.

Also, check if the passed filename ends with ".o" before stripping it.

The current code blindly chops the suffix:

    tmp[strlen(tmp) - 2] = '\0'

It will cause buffer under-run if strlen(tmp) < 2;

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-06-05 06:20:57 +09:00
Linus Torvalds
6f9b5ed8ca Char / Misc / Other smaller driver subsystem updates for 5.19-rc1
Here is the large set of char, misc, and other driver subsystem updates
 for 5.19-rc1.  The merge request for this has been delayed as I wanted
 to get lots of linux-next testing due to some late arrivals of changes
 for the habannalabs driver.
 
 Highlights of this merge are:
 	- habanalabs driver updates for new hardware types and fixes and
 	  other updates
 	- IIO driver tree merge which includes loads of new IIO drivers
 	  and cleanups and additions
 	- PHY driver tree merge with new drivers and small updates to
 	  existing ones
 	- interconnect driver tree merge with fixes and updates
 	- soundwire driver tree merge with some small fixes
 	- coresight driver tree merge with small fixes and updates
 	- mhi bus driver tree merge with lots of updates and new device
 	  support
 	- firmware driver updates
 	- fpga driver updates
 	- lkdtm driver updates (with a merge conflict, more on that
 	  below)
 	- extcon driver tree merge with small updates
 	- lots of other tiny driver updates and fixes and cleanups, full
 	  details in the shortlog.
 
 All of these have been in linux-next for almost 2 weeks with no reported
 problems.
 
 Note, there are 3 merge conflicts when merging this with your tree:
 	- MAINTAINERS, should be easy to resolve
 	- drivers/slimbus/qcom-ctrl.c, should be straightforward
 	  resolution
 	- drivers/misc/lkdtm/stackleak.c, not an easy resolution.  This
 	  has been noted in the linux-next tree for a while, and
 	  resolved there, here's a link to the resolution that Stephen
 	  came up with and that Kees says is correct:
 	  	https://lore.kernel.org/r/20220509185344.3fe1a354@canb.auug.org.au
 
 I will be glad to provide a merge point that contains these resolutions
 if that makes things any easier for you.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc / other smaller driver subsystem updates from Greg KH:
 "Here is the large set of char, misc, and other driver subsystem
  updates for 5.19-rc1. The merge request for this has been delayed as I
  wanted to get lots of linux-next testing due to some late arrivals of
  changes for the habannalabs driver.

  Highlights of this merge are:

   - habanalabs driver updates for new hardware types and fixes and
     other updates

   - IIO driver tree merge which includes loads of new IIO drivers and
     cleanups and additions

   - PHY driver tree merge with new drivers and small updates to
     existing ones

   - interconnect driver tree merge with fixes and updates

   - soundwire driver tree merge with some small fixes

   - coresight driver tree merge with small fixes and updates

   - mhi bus driver tree merge with lots of updates and new device
     support

   - firmware driver updates

   - fpga driver updates

   - lkdtm driver updates (with a merge conflict, more on that below)

   - extcon driver tree merge with small updates

   - lots of other tiny driver updates and fixes and cleanups, full
     details in the shortlog.

  All of these have been in linux-next for almost 2 weeks with no
  reported problems"

* tag 'char-misc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (387 commits)
  habanalabs: use separate structure info for each error collect data
  habanalabs: fix missing handle shift during mmap
  habanalabs: remove hdev from hl_ctx_get args
  habanalabs: do MMU prefetch as deferred work
  habanalabs: order memory manager messages
  habanalabs: return -EFAULT on copy_to_user error
  habanalabs: use NULL for eventfd
  habanalabs: update firmware header
  habanalabs: add support for notification via eventfd
  habanalabs: add topic to memory manager buffer
  habanalabs: handle race in driver fini
  habanalabs: add device memory scrub ability through debugfs
  habanalabs: use unified memory manager for CB flow
  habanalabs: unified memory manager new code for CB flow
  habanalabs/gaudi: set arbitration timeout to a high value
  habanalabs: add put by handle method to memory manager
  habanalabs: hide memory manager page shift
  habanalabs: Add separate poll interval value for protocol
  habanalabs: use get_task_pid() to take PID
  habanalabs: add prefetch flag to the MAP operation
  ...
2022-06-03 11:36:34 -07:00
Masahiro Yamada
31cb50b559 kbuild: check static EXPORT_SYMBOL* by script instead of modpost
The 'static' specifier and EXPORT_SYMBOL() are an odd combination.

Commit 15bfc2348d ("modpost: check for static EXPORT_SYMBOL*
functions") tried to detect it, but this check has false negatives.

Here is the sample code.

  Makefile:

    obj-y += foo1.o foo2.o

  foo1.c:

    #include <linux/export.h>
    static void foo(void) {}
    EXPORT_SYMBOL(foo);

  foo2.c:

    void foo(void) {}

foo1.c exports the static symbol 'foo', but modpost cannot catch it
because it is fooled by foo2.c, which has a global symbol with the
same name.

s->is_static is cleared if a global symbol with the same name is found
somewhere, but EXPORT_SYMBOL() and the global symbol do not necessarily
belong to the same compilation unit.

This check should be done per compilation unit, but I do not know how
to do it in modpost. modpost runs against vmlinux.o or modules, which
merges multiple objects, then forgets their origin.

modpost cannot parse individual objects because they may not be ELF but
LLVM IR when CONFIG_LTO_CLANG=y.

Add a simple bash script to parse the output from ${NM}. This works for
CONFIG_LTO_CLANG=y because llvm-nm can dump symbols of LLVM IR files.

Revert 15bfc2348d.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-06-01 23:07:02 +09:00
Masahiro Yamada
c25e1c5582 kbuild: do not create *.prelink.o for Clang LTO or IBT
When CONFIG_LTO_CLANG=y, additional intermediate *.prelink.o is created
for each module. Also, objtool is postponed until LLVM IR is converted
to ELF.

CONFIG_X86_KERNEL_IBT works in a similar way to postpone objtool until
objects are merged together.

This commit stops generating *.prelink.o, so the build flow will look
similar with/without LTO.

The following figures show how the LTO build currently works, and
how this commit is changing it.

Current build flow
==================

 [1] single-object module

                                      $(LD)
           $(CC)                     +objtool              $(LD)
    foo.c --------------------> foo.o -----> foo.prelink.o -----> foo.ko
                              (LLVM IR)          (ELF)       |    (ELF)
                                                             |
                                                 foo.mod.o --/
                                                 (LLVM IR)

 [2] multi-object module
                                      $(LD)
           $(CC)         $(AR)       +objtool               $(LD)
    foo1.c -----> foo1.o -----> foo.o -----> foo.prelink.o -----> foo.ko
                           |  (archive)          (ELF)       |    (ELF)
    foo2.c -----> foo2.o --/                                 |
                 (LLVM IR)                       foo.mod.o --/
                                                 (LLVM IR)

  One confusion is that foo.o in multi-object module is an archive
  despite of its suffix.

New build flow
==============

 [1] single-object module

  Since there is only one object, there is no need to keep the LLVM IR.
  Use $(CC)+$(LD) to generate an ELF object in one build rule. When LTO
  is disabled, $(LD) is unneeded because $(CC) produces an ELF object.

               $(CC)+$(LD)+objtool              $(LD)
    foo.c ----------------------------> foo.o ---------> foo.ko
                                        (ELF)     |      (ELF)
                                                  |
                                      foo.mod.o --/
                                      (LLVM IR)

 [2] multi-object module

  Previously, $(AR) was used to combine LLVM IR files into an archive,
  but there was no technical reason to do so. Use $(LD) to merge them
  into a single ELF object.

                               $(LD)
             $(CC)            +objtool          $(LD)
    foo1.c ---------> foo1.o ---------> foo.o ---------> foo.ko
                                 |      (ELF)     |      (ELF)
    foo2.c ---------> foo2.o ----/                |
                     (LLVM IR)        foo.mod.o --/
                                      (LLVM IR)

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
2022-05-29 18:39:35 +09:00
Masahiro Yamada
68fef6704e modpost: squash if...else-if in find_elf_symbol2()
if ((addr - sym->st_value) < distance) {
            distance = addr - sym->st_value;
            near = sym;
    } else if ((addr - sym->st_value) == distance) {
            near = sym;
    }

is equivalent to:

    if (addr - sym->st_value <= distance) {
            distance = addr - sym->st_value;
            near = sym;
    }

(The else-if block can overwrite 'distance' with the same value).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-27 16:16:35 +09:00
Masahiro Yamada
c5c468dcc2 modpost: reuse ARRAY_SIZE() macro for section_mismatch()
Move ARRAY_SIZE() from file2alias.c to modpost.h to reuse it in
section_mismatch().

Also, move the variable 'check' inside the for-loop.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-27 16:15:40 +09:00
Masahiro Yamada
76954527fe modpost: remove the unused argument of check_sec_ref()
check_sec_ref() does not use the first parameter 'mod'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-27 16:10:10 +09:00
Masahiro Yamada
d6b732666a modpost: fix undefined behavior of is_arm_mapping_symbol()
The return value of is_arm_mapping_symbol() is unpredictable when "$"
is passed in.

strchr(3) says:
  The strchr() and strrchr() functions return a pointer to the matched
  character or NULL if the character is not found. The terminating null
  byte is considered part of the string, so that if c is specified as
  '\0', these functions return a pointer to the terminator.

When str[1] is '\0', strchr("axtd", str[1]) is not NULL, and str[2] is
referenced (i.e. buffer overrun).

Test code
---------

  char str1[] = "abc";
  char str2[] = "ab";

  strcpy(str1, "$");
  strcpy(str2, "$");

  printf("test1: %d\n", is_arm_mapping_symbol(str1));
  printf("test2: %d\n", is_arm_mapping_symbol(str2));

Result
------

  test1: 0
  test2: 1

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-27 16:07:44 +09:00
Alexander Lobakin
b5beffa20d modpost: fix removing numeric suffixes
With the `-z unique-symbol` linker flag or any similar mechanism,
it is possible to trigger the following:

ERROR: modpost: "param_set_uint.0" [vmlinux] is a static EXPORT_SYMBOL

The reason is that for now the condition from remove_dot():

if (m && (s[n + m] == '.' || s[n + m] == 0))

which was designed to test if it's a dot or a '\0' after the suffix
is never satisfied.
This is due to that `s[n + m]` always points to the last digit of a
numeric suffix, not on the symbol next to it (from a custom debug
print added to modpost):

param_set_uint.0, s[n + m] is '0', s[n + m + 1] is '\0'

So it's off-by-one and was like that since 2014.

Fix this for the sake of any potential upcoming features, but don't
bother stable-backporting, as it's well hidden -- apart from that
LD flag, it can be triggered only with GCC LTO which never landed
upstream.

Fixes: fcd38ed0ff ("scripts: modpost: fix compilation warning")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-27 16:05:01 +09:00
Masahiro Yamada
7b4537199a kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.

Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.

It is time to get rid of this complexity.

Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.

Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.

Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.

No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.

Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-24 16:33:20 +09:00
Masahiro Yamada
f292d875d0 modpost: extract symbol versions from *.cmd files
Currently, CONFIG_MODVERSIONS needs extra link to embed the symbol
versions into ELF objects. Then, modpost extracts the version CRCs
from them.

The following figures show how it currently works, and how I am trying
to change it.

Current implementation
======================
                                                           |----------|
                 embed CRC      -------------------------->| final    |
       $(CC)       $(LD)       /  |---------|              | link for |
       -----> *.o -------> *.o -->| modpost |              | vmlinux  |
      /              /            |         |-- *.mod.c -->| or       |
     / genksyms     /             |---------|              | module   |
  *.c ------> *.symversions                                |----------|

Genksyms outputs the calculated CRCs in the form of linker script
(*.symversions), which is used by $(LD) to update the object.

If CONFIG_LTO_CLANG=y, the build process is much more complex. Embedding
the CRCs is postponed until the LLVM bitcode is converted into ELF,
creating another intermediate *.prelink.o.

However, this complexity is unneeded. There is no reason why we must
embed version CRCs in objects so early.

There is final link stage for vmlinux (scripts/link-vmlinux.sh) and
modules (scripts/Makefile.modfinal). We can link CRCs at the very last
moment.

New implementation
==================
                                                           |----------|
                   --------------------------------------->| final    |
       $(CC)      /    |---------|                         | link for |
       -----> *.o ---->|         |                         | vmlinux  |
      /                | modpost |--- .vmlinux.export.c -->| or       |
     / genksyms        |         |--- *.mod.c ------------>| module   |
  *.c ------> *.cmd -->|---------|                         |----------|

Pass the symbol versions to modpost as separate text data, which are
available in *.cmd files.

This commit changes modpost to extract CRCs from *.cmd files instead of
from ELF objects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-24 00:53:06 +09:00
Masahiro Yamada
69c4cc99bb modpost: add sym_find_with_module() helper
find_symbol() returns the first symbol found in the hash table. This
table is global, so it may return a symbol from an unexpected module.

There is a case where we want to search for a symbol with a given name
in a specified module.

Add sym_find_with_module(), which receives the module pointer as the
second argument. It is equivalent to find_module() if NULL is passed
as the module pointer.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-24 00:52:12 +09:00
Masahiro Yamada
2a66c3124a modpost: change the license of EXPORT_SYMBOL to bool type
There were more EXPORT_SYMBOL types in the past. The following commits
removed unused ones.

 - f1c3d73e97 ("module: remove EXPORT_SYMBOL_GPL_FUTURE")
 - 367948220f ("module: remove EXPORT_UNUSED_SYMBOL*")

There are 3 remaining in enum export, but export_unknown does not make
any sense because we never expect such a situation like "we do not know
how it was exported".

If the symbol name starts with "__ksymtab_", but the section name
does not start with "___ksymtab+" or "___ksymtab_gpl+", it is not an
exported symbol.

It occurs when a variable starting with "__ksymtab_" is directly defined:

   int __ksymtab_foo;

Presumably, there is no practical issue for using such a weird variable
name (but there is no good reason for doing so, either).

Anyway, that is not an exported symbol. Setting export_unknown is not
the right thing to do. Do not call sym_add_exported() in this case.

With pointless export_unknown removed, the export type finally becomes
boolean (either EXPORT_SYMBOL or EXPORT_SYMBOL_GPL).

I renamed the field name to is_gpl_only. EXPORT_SYMBOL_GPL sets it true.
Only GPL-compatible modules can use it.

I removed the orphan comment, "How a symbol is exported", which is
unrelated to sec_mismatch_count. It is about enum export.
See commit bd5cbcedf4 ("kbuild: export-type enhancement to modpost.c")

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:39 +09:00
Masahiro Yamada
ce79c406a2 modpost: remove left-over cross_compile declaration
This is a remnant of commit 6543becf26 ("mod/file2alias: make
modalias generation safe for cross compiling").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-11 21:46:39 +09:00
Masahiro Yamada
a44abaca0e modpost: move *.mod.c generation to write_mod_c_files()
A later commit will add more code to this list_for_each_entry loop.

Before that, move the loop body into a separate helper function.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:38 +09:00
Masahiro Yamada
7fedac9698 modpost: merge add_{intree_flag,retpoline,staging_flag} to add_header
add_intree_flag(), add_retpoline(), and add_staging_flag() are small
enough to be merged into add_header().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:38 +09:00
Masahiro Yamada
f18379a302 modpost: split new_symbol() to symbol allocation and hash table addition
new_symbol() does two things; allocate a new symbol and register it
to the hash table.

Using a separate function for each is easier to understand.

Replace new_symbol() with hash_add_symbol(). Remove the second parameter
of alloc_symbol().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
e76cc48d8e modpost: make sym_add_exported() always allocate a new symbol
Currently, sym_add_exported() does not allocate a symbol if the same
name symbol already exists in the hash table.

This does not reflect the real use cases. You can let an external
module override the in-tree one. In this case, the external module
will export the same name symbols as the in-tree one. However,
modpost simply ignores those symbols, then Module.symvers for the
external module loses its symbols.

sym_add_exported() should allocate a new symbol.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
b842271108 modpost: make multiple export error
This is currently a warning, but I think modpost should stop building
in this case.

If the same symbol is exported multiple times and we let it keep going,
the sanity check becomes difficult.

Only the legitimate case is that an external module overrides the
corresponding in-tree module to provide a different implementation
with the same interface.

Also, there exists an upstream example that exploits this feature.

  $ make M=tools/testing/nvdimm

... builds tools/testing/nvdimm/libnvdimm.ko. This is a mocked module
that overrides the symbols from drivers/nvdimm/libnvdimm.ko.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
f841536e8c modpost: dump Module.symvers in the same order of modules.order
modpost dumps the exported symbols into Module.symvers, but currently
in random order because it iterates in the hash table.

Add a linked list of exported symbols in struct module, so we can
iterate on symbols per module.

This commit makes Module.symvers much more readable; the outer loop in
write_dump() iterates over the modules in the order of modules.order,
and the inner loop dumps symbols in each module.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
ab489d6002 modpost: traverse the namespace_list in order
Use the doubly linked list to traverse the list in the added order.
This makes the code more consistent.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
4484054816 modpost: use doubly linked list for dump_lists
This looks easier to understand (just because this is a pattern in
the kernel code). No functional change is intended.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
8a69152be9 modpost: traverse unresolved symbols in order
Currently, modpost manages unresolved in a singly linked list; it adds
a new node to the head, and traverses the list from new to old.

Use a doubly linked list to keep the order in the symbol table in the
ELF file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
e882e89bcf modpost: add sym_add_unresolved() helper
Add a small helper, sym_add_unresolved() to ease the further
refactoring.

Remove the 'weak' argument from alloc_symbol() because it is sensible
only for unresolved symbols.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
325eba05e8 modpost: traverse modules in order
Currently, modpost manages modules in a singly linked list; it adds
a new node to the head, and traverses the list from new to old.

It works, but the error messages are shown in the reverse order.

If you have a Makefile like this:

  obj-m += foo.o bar.o

then, modpost shows error messages in bar.o, foo.o, in this order.

Use a doubly linked list to keep the order in modules.order; use
list_add_tail() for the node addition and list_for_each_entry() for
the list traverse.

Now that the kernel's list macros have been imported to modpost, I will
use them actively going forward.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
97aa4aef53 modpost: import include/linux/list.h
Import include/linux/list.h to use convenient list macros in modpost.

I dropped kernel-space code such as {WRITE,READ}_ONCE etc. and unneeded
macros.

I also imported container_of() from include/linux/container_of.h and
type definitions from include/linux/types.h.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
5066743e4c modpost: change mod->gpl_compatible to bool type
Currently, mod->gpl_compatible is tristate; it is set to -1 by default,
then to 1 or 0 when MODULE_LICENSE() is found.

Maybe, -1 was chosen to represent the 'unknown' license, but it is not
useful.

The current code:

    if (!mod->gpl_compatible)
            check_for_gpl_usage(exp->export, basename, exp->name);

... only cares whether gpl_compatible is zero or not.

Change it to a bool type with the initial value 'true', which has no
functional change.

The default value should be 'true' instead of 'false'.

Since commit 1d6cd39293 ("modpost: turn missing MODULE_LICENSE() into
error"), unknown module license is an error.

The error message, "missing MODULE_LICENSE()" is enough to explain the
issue. It is not sensible to show another message, "GPL-incompatible
module ... uses GPL-only symbol".

Add comments to explain this.

While I was here, I renamed gpl_compatible to is_gpl_compatible for
clarification, and also slightly refactored the code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
58e01fcae1 modpost: use bool type where appropriate
Use 'bool' to clarify that the valid value is true or false.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
70ddb48db4 modpost: move struct namespace_list to modpost.c
There is no good reason to define struct namespace_list in modpost.h

struct module has pointers to struct namespace_list, but that does
not require the definition of struct namespace_list.

Move it to modpost.c.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
4cae77ac58 modpost: retrieve the module dependency and CRCs in check_exports()
Do not repeat the similar code.

It is simpler to do this in check_exports() instead of add_versions().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
23beb44a0e modpost: add a separate error for exported symbols without definition
It took me a while to understand the intent of "exp->module == mod".

This code goes back to 2003. [1]

The commit is not in this git repository, and might be worth a little
explanation.

You can add EXPORT_SYMBOL() without having its definition in the same
file (but you need to put a declaration).

This is typical when EXPORT_SYMBOL() is added in a C file, but the
actual implementation is in a separate assembly file.

One example is arch/arm/kernel/armksyms.c

In the old days, EXPORT_SYMBOL() was only available in C files (but
this limitation does not exist any more). If you forget to add the
definition, this error occurs.

Add a separate, clearer message for this case. It should be an error
even if KBUILD_MODPOST_WARN is given.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=2763b6bcb96e6a38a2fe31108fe5759ec5bcc80a

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
594ade3eef modpost: remove stale comment about sym_add_exported()
The description,

  it may have already been added without a
  CRC, in this case just update the CRC

... is no longer valid.

In the old days, this function was used to update the CRC as well.

Commit 040fcc819a ("kbuild: improved modversioning support for
external modules") started to use a separate function (sym_update_crc)
for updating the CRC.

The first part, "Add an exported symbol" is correct, but it is too
obvious from the function name. Drop this comment entirely.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
c155a47d83 modpost: do not write out any file when error occurred
If an error occurs, modpost will fail anyway. Do not write out
any content (, which might be invalid).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
15a28c7c72 modpost: use snprintf() instead of sprintf() for safety
Use snprintf() to avoid the potential buffer overflow, and also
check the return value to detect the too long path.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
22f26f2177 kbuild: get rid of duplication in *.mod files
It is allowed to add the same objects multiple times to obj-y / obj-m:

  obj-y += foo.o foo.o foo.o
  obj-m += bar.o bar.o bar.o

It is also allowed to add the same objects multiple times to a composite
module:

  obj-m += foo.o
  foo-y := foo1.o foo2.o foo2.o foo1.o

This flexibility is useful because the same object might be selected by
different CONFIG options, like this:

  obj-m               += foo.o
  foo-y               := foo1.o
  foo-$(CONFIG_FOO_X) += foo2.o
  foo-$(CONFIG_FOO_Y) += foo2.o

The duplicated objects are omitted at link time. It works naturally in
Makefiles because GNU Make removes duplication in $^ without changing
the order.

It is working well, almost...

A small flaw I notice is, *.mod contains duplication in such a case.

This is probably not a big deal. As far as I know, the only small
problem is scripts/mod/sumversion.c parses the same file multiple
times.

I am fixing this because I plan to reuse *.mod for other purposes,
where the duplication can be problematic.

The code change is quite simple. We already use awk to drop duplicated
lines in modules.order (see cmd_modules_order in the same file).
I copied the code, but changed RS to use spaces as record separators.

I also changed the file format to list one object per line.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
9413e76405 kbuild: split the second line of *.mod into *.usyms
The *.mod files have two lines; the first line lists the member objects
of the module, and the second line, if CONFIG_TRIM_UNUSED_KSYMS=y, lists
the undefined symbols.

Currently, we generate *.mod after constructing composite modules,
otherwise, we cannot compute the second line. No prerequisite is
required to print the first line.

They are orthogonal. Splitting them into separate commands will ease
further cleanups.

This commit splits the list of undefined symbols out to *.usyms files.

Previously, the list of undefined symbols ended up with a very long
line, but now it has one symbol per line.

Use sed like we did before commit 7d32358be8 ("kbuild: avoid split
lines in .mod files").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
79f646e865 modpost: remove annoying namespace_from_kstrtabns()
There are two call sites for sym_update_namespace().

When the symbol has no namespace, s->namespace is set to NULL,
but the conversion from "" to NULL is done in two different places.

[1] read_symbols()

  This gets the namespace from __kstrtabns_<symbol>. If the symbol has
  no namespace, sym_get_data(info, sym) returns the empty string "".
  namespace_from_kstrtabns() converts it to NULL before it is passed to
  sym_update_namespace().

[2] read_dump()

  This gets the namespace from the dump file, *.symvers. If the symbol
  has no namespace, the 'namespace' is the empty string "", which is
  directly passed into sym_update_namespace(). The conversion from
  "" to NULL is done in sym_update_namespace().

namespace_from_kstrtabns() exists only for creating this inconsistency.

Remove namespace_from_kstrtabns() so that sym_update_namespace() is
consistently passed with "" instead of NULL.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:58 +09:00
Masahiro Yamada
b5f1a52a59 modpost: remove redundant initializes for static variables
These are initialized with zeros without explicit initializers.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:58 +09:00
Masahiro Yamada
535b3e05f4 modpost: move export_from_secname() call to more relevant place
The assigned 'export' is only used when

    if (strstarts(symname, "__ksymtab_"))

is met. The else-part of the assignment is the dead code.

Move the export_from_secname() call to where it is used.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:58 +09:00
Masahiro Yamada
7ce3e410e0 modpost: remove useless export_from_sec()
With commit 1743694eb2 ("modpost: stop symbol preloading for
modversion CRC") applied, now export_from_sec() is useless.

handle_symbol() is called for every symbol in the ELF.

When 'symname' does not start with "__ksymtab", export_from_sec() is
called, and the returned value is stored in 'export'.

It is used in the last part of handle_symbol():

    if (strstarts(symname, "__ksymtab_")) {
            name = symname + strlen("__ksymtab_");
            sym_add_exported(name, mod, export);
    }

'export' is used only when 'symname' starts with "__ksymtab_".

So, the value returned by export_from_sec() is never used.

Remove useless export_from_sec(). This makes further cleanups possible.

I put the temporary code:

    export = export_unknown;

Otherwise, I would get the compiler warning:

    warning: 'export' may be used uninitialized in this function [-Wmaybe-uninitialized]

This is apparently false positive because

    if (strstarts(symname, "__ksymtab_")

... is a stronger condition than:

    if (strstarts(symname, "__ksymtab")

Anyway, this part will be cleaned up by the next commit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:30 +09:00
Manivannan Sadhasivam
c268c0a8a3 bus: mhi: ep: Add uevent support for module autoloading
Add uevent support to MHI endpoint bus so that the client drivers can be
autoloaded by udev when the MHI endpoint devices gets created. The client
drivers are expected to provide MODULE_DEVICE_TABLE with the MHI id_table
struct so that the alias can be exported.

The MHI endpoint reused the mhi_device_id structure of the MHI bus.

Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220405135754.6622-19-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26 13:17:42 +02:00
Masahiro Yamada
bf5c0c2231 modpost: restore the warning message for missing symbol versions
This log message was accidentally chopped off.

I was wondering why this happened, but checking the ML log, Mark
precisely followed my suggestion [1].

I just used "..." because I was too lazy to type the sentence fully.
Sorry for the confusion.

[1]: https://lore.kernel.org/all/CAK7LNAR6bXXk9-ZzZYpTqzFqdYbQsZHmiWspu27rtsFxvfRuVA@mail.gmail.com/

Fixes: 4a6795933a ("kbuild: modpost: Explicitly warn about unprototyped symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-04-03 03:11:51 +09:00
Linus Torvalds
7001052160 Add support for Intel CET-IBT, available since Tigerlake (11th gen), which is a
coarse grained, hardware based, forward edge Control-Flow-Integrity mechanism
 where any indirect CALL/JMP must target an ENDBR instruction or suffer #CP.
 
 Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation is
 limited to 2 instructions (and typically fewer) on branch targets not starting
 with ENDBR. CET-IBT also limits speculation of the next sequential instruction
 after the indirect CALL/JMP [1].
 
 CET-IBT is fundamentally incompatible with retpolines, but provides, as
 described above, speculation limits itself.
 
 [1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html
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Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
2022-03-27 10:17:23 -07:00
Linus Torvalds
50560ce6a0 Kbuild -std=gnu11 updates for v5.18
Linus pointed out the benefits of C99 some years ago, especially variable
 declarations in loops [1]. At that time, we were not ready for the
 migration due to old compilers.
 
 Recently, Jakob Koschel reported a bug in list_for_each_entry(), which
 leaks the invalid pointer out of the loop [2]. In the discussion, we
 agreed that the time had come. Now that GCC 5.1 is the minimum compiler
 version, there is nothing to prevent us from going to -std=gnu99, or even
 straight to -std=gnu11.
 
 Discussions for a better list iterator implementation are ongoing, but
 this patch set must land first.
 
 [1] https://lore.kernel.org/all/CAHk-=wgr12JkKmRd21qh-se-_Gs69kbPgR9x4C+Es-yJV2GLkA@mail.gmail.com/
 [2] https://lore.kernel.org/lkml/86C4CE7D-6D93-456B-AA82-F8ADEACA40B7@gmail.com/
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Merge tag 'kbuild-gnu11-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild update for C11 language base from Masahiro Yamada:
 "Kbuild -std=gnu11 updates for v5.18

  Linus pointed out the benefits of C99 some years ago, especially
  variable declarations in loops [1]. At that time, we were not ready
  for the migration due to old compilers.

  Recently, Jakob Koschel reported a bug in list_for_each_entry(), which
  leaks the invalid pointer out of the loop [2]. In the discussion, we
  agreed that the time had come. Now that GCC 5.1 is the minimum
  compiler version, there is nothing to prevent us from going to
  -std=gnu99, or even straight to -std=gnu11.

  Discussions for a better list iterator implementation are ongoing, but
  this patch set must land first"

[1] https://lore.kernel.org/all/CAHk-=wgr12JkKmRd21qh-se-_Gs69kbPgR9x4C+Es-yJV2GLkA@mail.gmail.com/
[2] https://lore.kernel.org/lkml/86C4CE7D-6D93-456B-AA82-F8ADEACA40B7@gmail.com/

* tag 'kbuild-gnu11-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Kbuild: use -std=gnu11 for KBUILD_USERCFLAGS
  Kbuild: move to -std=gnu11
  Kbuild: use -Wdeclaration-after-statement
  Kbuild: add -Wno-shift-negative-value where -Wextra is used
2022-03-25 11:48:01 -07:00
Peter Zijlstra
d31ed5d767 kbuild: Fixup the IBT kbuild changes
Masahiro-san deemed my kbuild changes to support whole module objtool
runs too terrible to live and gracefully provided an alternative.

Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/CAK7LNAQ2mYMnOKMQheVi+6byUFE3KEkjm1zcndNUfe0tORGvug@mail.gmail.com
2022-03-22 21:12:04 +01:00
Mark Rutland
4d94f910e7 Kbuild: use -Wdeclaration-after-statement
The kernel is moving from using `-std=gnu89` to `-std=gnu11`, permitting
the use of additional C11 features such as for-loop initial declarations.

One contentious aspect of C99 is that it permits mixed declarations and
code, and for now at least, it seems preferable to enforce that
declarations must come first.

These warnings were already enabled in the kernel itself, but not
for KBUILD_USERCFLAGS or the compat VDSO on arch/arm64, which uses
a separate set of CFLAGS.

This patch fixes an existing violation in modpost.c, which is not
reported because of the missing flag in KBUILD_USERCFLAGS:

| scripts/mod/modpost.c: In function ‘match’:
| scripts/mod/modpost.c:837:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
|   837 |   const char *endp = p + strlen(p) - 1;
|       |   ^~~~~

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[arnd: don't add a duplicate flag to the default set, update changelog]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 (x86-64)
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-03-13 17:31:10 +09:00
Vasily Gorbik
1d2ad08480 s390/nospec: add an option to use thunk-extern
Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler
options expoline thunks are put into individual COMDAT group sections. s390
is the only architecture which has group sections and it has implications
for kpatch and objtool tools support.

Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern
is an alternative, which comes with a need to generate all required
expoline thunks manually. Unfortunately modules area is too far away from
the kernel image, and expolines from the kernel image cannon be used.
But since all new distributions (except Debian) build kernels for machine
generations newer than z10, where "exrl" instruction is available, that
leaves only 16 expolines thunks possible.

Provide an option to build the kernel with
-mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for
z10 or newer. This also requires to postlink expoline thunks into all
modules explicitly. Currently modules already contain most expolines
anyhow.

Unfortunately -mindirect-branch=thunk-extern and
-mfunction-return=thunk-extern options support is broken in gcc <= 11.2.
Additional compile test is required to verify proper gcc support.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-10 15:58:17 +01:00
Linus Torvalds
f1b744f65e RISC-V Patches for the 5.17 Merge Window, Part 1
* Support for the DA9063 as used on the HiFive Unmatched.
 * Support for relative extables, which puts us in line with other
   architectures and save some space in vmlinux.
 * A handful of kexec fixes/improvements, including the ability to run
   crash kernels from PCI-addressable memory on the HiFive Unmatched.
 * Support for the SBI SRST extension, which allows systems that do not
   have an explicit driver in Linux to reboot.
 * A handful of fixes and cleanups, including to the defconfigs and
   device trees.
 
 ---
 This time I do expect to have a part 2, as there's still some smaller
 patches on the list.  I was hoping to get through more of that over the
 weekend, but I got distracted with the ABI issues.  Figured it's better
 to send this sooner rather than waiting.
 
 Included are my merge resolutions against a master from this morning, if
 that helps any:
 
 diff --cc arch/riscv/include/asm/sbi.h
 index 289621da4a2a,9c46dd3ff4a2..000000000000
 --- a/arch/riscv/include/asm/sbi.h
 +++ b/arch/riscv/include/asm/sbi.h
 @@@ -27,7 -27,14 +27,15 @@@ enum sbi_ext_id
         SBI_EXT_IPI = 0x735049,
         SBI_EXT_RFENCE = 0x52464E43,
         SBI_EXT_HSM = 0x48534D,
  +      SBI_EXT_SRST = 0x53525354,
 +
 +       /* Experimentals extensions must lie within this range */
 +       SBI_EXT_EXPERIMENTAL_START = 0x08000000,
 +       SBI_EXT_EXPERIMENTAL_END = 0x08FFFFFF,
 +
 +       /* Vendor extensions must lie within this range */
 +       SBI_EXT_VENDOR_START = 0x09000000,
 +       SBI_EXT_VENDOR_END = 0x09FFFFFF,
   };
 
   enum sbi_ext_base_fid {
 diff --git a/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts b/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
 index e03a4c94cf3f..6bfa1f24d3de 100644
 --- a/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
 +++ b/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
 @@ -188,14 +188,6 @@ vdd_ldo11: ldo11 {
                                 regulator-always-on;
                         };
                 };
 -
 -               rtc {
 -                       compatible = "dlg,da9063-rtc";
 -               };
 -
 -               wdt {
 -                       compatible = "dlg,da9063-watchdog";
 -               };
         };
  };
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Merge tag 'riscv-for-linus-5.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the DA9063 as used on the HiFive Unmatched.

 - Support for relative extables, which puts us in line with other
   architectures and save some space in vmlinux.

 - A handful of kexec fixes/improvements, including the ability to run
   crash kernels from PCI-addressable memory on the HiFive Unmatched.

 - Support for the SBI SRST extension, which allows systems that do not
   have an explicit driver in Linux to reboot.

 - A handful of fixes and cleanups, including to the defconfigs and
   device trees.

* tag 'riscv-for-linus-5.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (52 commits)
  RISC-V: Use SBI SRST extension when available
  riscv: mm: fix wrong phys_ram_base value for RV64
  RISC-V: Use common riscv_cpuid_to_hartid_mask() for both SMP=y and SMP=n
  riscv: head: remove useless __PAGE_ALIGNED_BSS and .balign
  riscv: errata: alternative: mark vendor_patch_func __initdata
  riscv: head: make secondary_start_common() static
  riscv: remove cpu_stop()
  riscv: try to allocate crashkern region from 32bit addressible memory
  riscv: use hart id instead of cpu id on machine_kexec
  riscv: Don't use va_pa_offset on kdump
  riscv: dts: sifive: fu540-c000: Fix PLIC node
  riscv: dts: sifive: fu540-c000: Drop bogus soc node compatible values
  riscv: dts: sifive: Group tuples in register properties
  riscv: dts: sifive: Group tuples in interrupt properties
  riscv: dts: microchip: mpfs: Group tuples in interrupt properties
  riscv: dts: microchip: mpfs: Fix clock controller node
  riscv: dts: microchip: mpfs: Fix reference clock node
  riscv: dts: microchip: mpfs: Fix PLIC node
  riscv: dts: microchip: mpfs: Drop empty chosen node
  riscv: dts: canaan: Group tuples in interrupt properties
  ...
2022-01-19 11:38:21 +02:00
Jisheng Zhang
bb1f85d604
riscv: switch to relative exception tables
Similar as other architectures such as arm64, x86 and so on, use
offsets relative to the exception table entry values rather than
absolute addresses for both the exception locationand the fixup.

However, RISCV label difference will actually produce two relocations,
a pair of R_RISCV_ADD32 and R_RISCV_SUB32. Take below simple code for
example:

$ cat test.S
.section .text
1:
        nop
.section __ex_table,"a"
        .balign 4
        .long (1b - .)
.previous

$ riscv64-linux-gnu-gcc -c test.S
$ riscv64-linux-gnu-readelf -r test.o
Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries:
  Offset          Info           Type           Sym. Value    Sym. Name + Addend
000000000000  000600000023 R_RISCV_ADD32     0000000000000000 .L1^B1 + 0
000000000000  000500000027 R_RISCV_SUB32     0000000000000000 .L0  + 0

The modpost will complain the R_RISCV_SUB32 relocation, so we need to
patch modpost.c to skip this relocation for .rela__ex_table section.

After this patch, the __ex_table section size of defconfig vmlinux is
reduced from 7072 Bytes to 3536 Bytes.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-05 17:52:20 -08:00
Thomas Weißschuh
fa443bc3c1 HID: intel-ish-hid: add support for MODULE_DEVICE_TABLE()
This allows to selectively autoload drivers for ISH devices.
Currently all ISH drivers are loaded for all systems having any ISH
device.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-11-09 11:41:46 +01:00
Linus Torvalds
b250e6d141 Kbuild updates for v5.15
- Add -s option (strict mode) to merge_config.sh to make it fail when
    any symbol is redefined.
 
  - Show a warning if a different compiler is used for building external
    modules.
 
  - Infer --target from ARCH for CC=clang to let you cross-compile the
    kernel without CROSS_COMPILE.
 
  - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
 
  - Add <linux/stdarg.h> to the kernel source instead of borrowing
    <stdarg.h> from the compiler.
 
  - Add Nick Desaulniers as a Kbuild reviewer.
 
  - Drop stale cc-option tests.
 
  - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
    to handle symbols in inline assembly.
 
  - Show a warning if 'FORCE' is missing for if_changed rules.
 
  - Various cleanups
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Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add <linux/stdarg.h> to the kernel source instead of borrowing
   <stdarg.h> from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
2021-09-03 15:33:47 -07:00
Linus Torvalds
7cca308cfd powerpc updates for 5.15
- Convert pseries & powernv to use MSI IRQ domains.
 
  - Rework the pseries CPU numbering so that CPUs that are removed, and later re-added, are
    given a CPU number on the same node as previously, when possible.
 
  - Add support for a new more flexible device-tree format for specifying NUMA distances.
 
  - Convert powerpc to GENERIC_PTDUMP.
 
  - Retire sbc8548 and sbc8641d board support.
 
  - Various other small features and fixes.
 
 Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Anton Blanchard, Cédric Le Goater,
 Christophe Leroy, Emmanuel Gil Peyrot, Fabiano Rosas, Fangrui Song, Finn Thain, Gautham R.
 Shenoy, Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Laurent Dufour, Leonardo
 Bras, Lukas Bulwahn, Marc Zyngier, Masahiro Yamada, Michal Suchanek, Nathan Chancellor,
 Nicholas Piggin, Parth Shah, Paul Gortmaker, Pratik R. Sampat, Randy Dunlap, Sebastian
 Andrzej Siewior, Srikar Dronamraju, Wan Jiabing, Xiongwei Song, Zheng Yongjun.
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Merge tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Convert pseries & powernv to use MSI IRQ domains.

 - Rework the pseries CPU numbering so that CPUs that are removed, and
   later re-added, are given a CPU number on the same node as
   previously, when possible.

 - Add support for a new more flexible device-tree format for specifying
   NUMA distances.

 - Convert powerpc to GENERIC_PTDUMP.

 - Retire sbc8548 and sbc8641d board support.

 - Various other small features and fixes.

Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Anton Blanchard,
Cédric Le Goater, Christophe Leroy, Emmanuel Gil Peyrot, Fabiano Rosas,
Fangrui Song, Finn Thain, Gautham R.  Shenoy, Hari Bathini, Joel
Stanley, Jordan Niethe, Kajol Jain, Laurent Dufour, Leonardo Bras, Lukas
Bulwahn, Marc Zyngier, Masahiro Yamada, Michal Suchanek, Nathan
Chancellor, Nicholas Piggin, Parth Shah, Paul Gortmaker, Pratik R.
Sampat, Randy Dunlap, Sebastian Andrzej Siewior, Srikar Dronamraju, Wan
Jiabing, Xiongwei Song, and Zheng Yongjun.

* tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (154 commits)
  powerpc/bug: Cast to unsigned long before passing to inline asm
  powerpc/ptdump: Fix generic ptdump for 64-bit
  KVM: PPC: Fix clearing never mapped TCEs in realmode
  powerpc/pseries/iommu: Rename "direct window" to "dma window"
  powerpc/pseries/iommu: Make use of DDW for indirect mapping
  powerpc/pseries/iommu: Find existing DDW with given property name
  powerpc/pseries/iommu: Update remove_dma_window() to accept property name
  powerpc/pseries/iommu: Reorganize iommu_table_setparms*() with new helper
  powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()
  powerpc/pseries/iommu: Allow DDW windows starting at 0x00
  powerpc/pseries/iommu: Add ddw_list_new_entry() helper
  powerpc/pseries/iommu: Add iommu_pseries_alloc_table() helper
  powerpc/kernel/iommu: Add new iommu_table_in_use() helper
  powerpc/pseries/iommu: Replace hard-coded page shift
  powerpc/numa: Update cpu_cpu_map on CPU online/offline
  powerpc/numa: Print debug statements only when required
  powerpc/numa: convert printk to pr_xxx
  powerpc/numa: Drop dbg in favour of pr_debug
  powerpc/smp: Enable CACHE domain for shared processor
  powerpc/smp: Update cpu_core_map on all PowerPc systems
  ...
2021-09-03 11:22:50 -07:00
Masahiro Yamada
e54dd93a08 modpost: get the *.mod file path more simply
get_src_version() strips 'o' or 'lto.o' from the end of the object file
path (so, postfixlen is 1 or 5), then adds 'mod'.

If you look at the code closely, mod->name already holds the base path
with the extension stripped.

Most of the code changes made by commit 7ac204b545 ("modpost: lto:
strip .lto from module names") was actually unneeded.

sumversion.c does not need strends(), so it can get back local in
modpost.c again.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-09-03 08:17:21 +09:00
Max Gurtovoy
cc6711b0bf PCI / VFIO: Add 'override_only' support for VFIO PCI sub system
Expose an 'override_only' helper macro (i.e.
PCI_DRIVER_OVERRIDE_DEVICE_VFIO) for VFIO PCI sub system and add the
required code to prefix its matching entries with "vfio_" in
modules.alias file.

It allows VFIO device drivers to include match entries in the
modules.alias file produced by kbuild that are not used for normal
driver autoprobing and module autoloading. Drivers using these match
entries can be connected to the PCI device manually, by userspace, using
the existing driver_override sysfs.

For example the resulting modules.alias may have:

  alias pci:v000015B3d00001021sv*sd*bc*sc*i* mlx5_core
  alias vfio_pci:v000015B3d00001021sv*sd*bc*sc*i* mlx5_vfio_pci
  alias vfio_pci:v*d*sv*sd*bc*sc*i* vfio_pci

In this example mlx5_core and mlx5_vfio_pci match to the same PCI
device. The kernel will autoload and autobind to mlx5_core but the
kernel and udev mechanisms will ignore mlx5_vfio_pci.

When userspace wants to change a device to the VFIO subsystem it can
implement a generic algorithm:

   1) Identify the sysfs path to the device:
    /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0

   2) Get the modalias string from the kernel:
    $ cat /sys/bus/pci/devices/0000:01:00.0/modalias
    pci:v000015B3d00001021sv000015B3sd00000001bc02sc00i00

   3) Prefix it with vfio_:
    vfio_pci:v000015B3d00001021sv000015B3sd00000001bc02sc00i00

   4) Search modules.alias for the above string and select the entry that
      has the fewest *'s:
    alias vfio_pci:v000015B3d00001021sv*sd*bc*sc*i* mlx5_vfio_pci

   5) modprobe the matched module name:
    $ modprobe mlx5_vfio_pci

   6) cat the matched module name to driver_override:
    echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:01:00.0/driver_override

   7) unbind device from original module
     echo 0000:01:00.0 > /sys/bus/pci/devices/0000:01:00.0/driver/unbind

   8) probe PCI drivers (or explicitly bind to mlx5_vfio_pci)
    echo 0000:01:00.0 > /sys/bus/pci/drivers_probe

The algorithm is independent of bus type. In future the other buses with
VFIO device drivers, like platform and ACPI, can use this algorithm as
well.

This patch is the infrastructure to provide the information in the
modules.alias to userspace. Convert the only VFIO pci_driver which results
in one new line in the modules.alias:

  alias vfio_pci:v*d*sv*sd*bc*sc*i* vfio_pci

Later series introduce additional HW specific VFIO PCI drivers, such as
mlx5_vfio_pci.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>  # for pci.h
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-11-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-26 10:36:51 -06:00
Christophe Leroy
1e688dd2a3 powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto
Using asm goto in __WARN_FLAGS() and WARN_ON() allows more
flexibility to GCC.

For that add an entry to the exception table so that
program_check_exception() knowns where to resume execution
after a WARNING.

Here are two exemples. The first one is done on PPC32 (which
benefits from the previous patch), the second is on PPC64.

	unsigned long test(struct pt_regs *regs)
	{
		int ret;

		WARN_ON(regs->msr & MSR_PR);

		return regs->gpr[3];
	}

	unsigned long test9w(unsigned long a, unsigned long b)
	{
		if (WARN_ON(!b))
			return 0;
		return a / b;
	}

Before the patch:

	000003a8 <test>:
	 3a8:	81 23 00 84 	lwz     r9,132(r3)
	 3ac:	71 29 40 00 	andi.   r9,r9,16384
	 3b0:	40 82 00 0c 	bne     3bc <test+0x14>
	 3b4:	80 63 00 0c 	lwz     r3,12(r3)
	 3b8:	4e 80 00 20 	blr

	 3bc:	0f e0 00 00 	twui    r0,0
	 3c0:	80 63 00 0c 	lwz     r3,12(r3)
	 3c4:	4e 80 00 20 	blr

	0000000000000bf0 <.test9w>:
	 bf0:	7c 89 00 74 	cntlzd  r9,r4
	 bf4:	79 29 d1 82 	rldicl  r9,r9,58,6
	 bf8:	0b 09 00 00 	tdnei   r9,0
	 bfc:	2c 24 00 00 	cmpdi   r4,0
	 c00:	41 82 00 0c 	beq     c0c <.test9w+0x1c>
	 c04:	7c 63 23 92 	divdu   r3,r3,r4
	 c08:	4e 80 00 20 	blr

	 c0c:	38 60 00 00 	li      r3,0
	 c10:	4e 80 00 20 	blr

After the patch:

	000003a8 <test>:
	 3a8:	81 23 00 84 	lwz     r9,132(r3)
	 3ac:	71 29 40 00 	andi.   r9,r9,16384
	 3b0:	40 82 00 0c 	bne     3bc <test+0x14>
	 3b4:	80 63 00 0c 	lwz     r3,12(r3)
	 3b8:	4e 80 00 20 	blr

	 3bc:	0f e0 00 00 	twui    r0,0

	0000000000000c50 <.test9w>:
	 c50:	7c 89 00 74 	cntlzd  r9,r4
	 c54:	79 29 d1 82 	rldicl  r9,r9,58,6
	 c58:	0b 09 00 00 	tdnei   r9,0
	 c5c:	7c 63 23 92 	divdu   r3,r3,r4
	 c60:	4e 80 00 20 	blr

	 c70:	38 60 00 00 	li      r3,0
	 c74:	4e 80 00 20 	blr

In the first exemple, we see GCC doesn't need to duplicate what
happens after the trap.

In the second exemple, we see that GCC doesn't need to emit a test
and a branch in the likely path in addition to the trap.

We've got some WARN_ON() in .softirqentry.text section so it needs
to be added in the OTHER_TEXT_SECTIONS in modpost.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/389962b1b702e3c78d169e59bcfac56282889173.1618331882.git.christophe.leroy@csgroup.eu
2021-08-15 13:49:24 +10:00
Mark Brown
4a6795933a kbuild: modpost: Explicitly warn about unprototyped symbols
One common cause of modpost version generation failures is a failure to
prototype exported assembly functions - the tooling requires this for
exported functions even if they are not and should not be called from C
code in order to do the version mangling for symbols. Unfortunately the
error message is currently rather abstruse, simply saying that "version
generation failed" and even diving into the code doesn't directly show
what's going on since there's several steps between the problem and it
being observed.

Provide an explicit hint as to the likely cause of a version generation
failure to help anyone who runs into this in future more readily diagnose
and fix the problem.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-06-17 10:01:05 +09:00
Masahiro Yamada
9009b45581 .gitignore: prefix local generated files with a slash
The pattern prefixed with '/' matches files in the same directory,
but not ones in sub-directories.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Andra Paraschiv <andraprs@amazon.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Gabriel Krisman Bertazi <krisman@collabora.com>
2021-05-02 00:43:35 +09:00
Yonghong Song
1fdd7433a9 kbuild: add an elfnote for whether vmlinux is built with lto
Currently, clang LTO built vmlinux won't work with pahole.
LTO introduced cross-cu dwarf tag references and broke
current pahole model which handles one cu as a time.
The solution is to merge all cu's as one pahole cu as in [1].
We would like to do this merging only if cross-cu dwarf
references happens. The LTO build mode is a pretty good
indication for that.

In earlier version of this patch ([2]), clang flag
-grecord-gcc-switches is proposed to add to compilation flags
so pahole could detect "-flto" and then merging cu's.
This will increate the binary size of 1% without LTO though.

Arnaldo suggested to use a note to indicate the vmlinux
is built with LTO. Such a cheap way to get whether the vmlinux
is built with LTO or not helps pahole but is also useful
for tracing as LTO may inline/delete/demote global functions,
promote static functions, etc.

So this patch added an elfnote with a new type LINUX_ELFNOTE_LTO_INFO.
The owner of the note is "Linux".

With gcc 8.4.1 and clang trunk, without LTO, I got
  $ readelf -n vmlinux
  Displaying notes found in: .notes
    Owner                Data size        Description
  ...
    Linux                0x00000004       func
     description data: 00 00 00 00
  ...
With "readelf -x ".notes" vmlinux", I can verify the above "func"
with type code 0x101.

With clang thin-LTO, I got the same as above except the following:
     description data: 01 00 00 00
which indicates the vmlinux is built with LTO.

  [1] https://lore.kernel.org/bpf/20210325065316.3121287-1-yhs@fb.com/
  [2] https://lore.kernel.org/bpf/20210331001623.2778934-1-yhs@fb.com/

Suggested-by: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v12.0.0-rc4 (x86-64)
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:25:42 +09:00
Bhaskar Chowdhury
f3945833e4 scripts: modpost.c: Fix a few typos
s/agorithm/algorithm/
s/criterias/criteria/
s/targetting/targeting/   ....two different places.

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:21:45 +09:00
Masahiro Yamada
4475dff55c kbuild: fix false-positive modpost warning when all symbols are trimmed
Nathan reports that the mips defconfig emits the following warning:

  WARNING: modpost: Symbol info of vmlinux is missing. Unresolved symbol check will be entirely skipped.

This false-positive happens when CONFIG_TRIM_UNUSED_KSYMS is enabled,
but no CONFIG option is set to 'm'.

Commit a0590473c5 ("nfs: fix PNFS_FLEXFILE_LAYOUT Kconfig default")
turned the last 'm' into 'y' for the mips defconfig, and uncovered
this issue.

In this case, the module feature itself is enabled, but we have no
module to build. As a result, CONFIG_TRIM_UNUSED_KSYMS drops all the
instances of EXPORT_SYMBOL. Then, modpost wrongly assumes vmlinux is
missing because vmlinux.symvers is empty. (As another false-positive
case, you can create a module that does not use any symbol of vmlinux).

The current behavior is to entirely suppress the unresolved symbol
warnings when vmlinux is missing just because there are too many.
I found the origin of this code in the historical git tree. [1]

If this is a matter of noisiness, I think modpost can display the
first 10 warnings, and the number of suppressed warnings at the end.

You will get a bit noisier logs when you run 'make modules' without
vmlinux, but such warnings are better to show because you never know
the resulting modules are actually loadable or not.

This commit changes the following:

 - If any of input *.symver files is missing, pass -w option to let
   the module build keep going with warnings instead of errors.

 - If there are too many (10+) unresolved symbol warnings, show only
   the first 10, and also the number of suppressed warnings.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=1cc0e0529569bf6a94f6d49770aa6d4b599d2c46

Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:17:53 +09:00
Masahiro Yamada
69bc8d386a kbuild: generate Module.symvers only when vmlinux exists
The external module build shows the following warning if Module.symvers
is missing in the kernel tree.

  WARNING: Symbol version dump "Module.symvers" is missing.
           Modules may not have dependencies or modversions.

I think this is an important heads-up because the resulting modules may
not work as expected. This happens when you did not build the entire
kernel tree, for example, you might have prepared the minimal setups
for external modules by 'make defconfig && make modules_preapre'.

A problem is that 'make modules' creates Module.symvers even without
vmlinux. In this case, that warning is suppressed since Module.symvers
already exists in spite of its incomplete content.

The incomplete (i.e. invalid) Module.symvers should not be created.

This commit changes the second pass of modpost to dump symbols into
modules-only.symvers. The final Module.symvers is created by
concatenating vmlinux.symvers and modules-only.symvers if both exist.

Module.symvers is supposed to collect symbols from both vmlinux and
modules. It might be a bit confusing, and I am not quite sure if it
is an official interface, but presumably it is difficult to rename it
because some tools (e.g. kmod) parse it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:17:02 +09:00
Linus Torvalds
e229b429bb Char/Misc driver patches for 5.12-rc1
Here is the large set of char/misc/whatever driver subsystem updates for
 5.12-rc1.  Over time it seems like this tree is collecting more and more
 tiny driver subsystems in one place, making it easier for those
 maintainers, which is why this is getting larger.
 
 Included in here are:
 	- coresight driver updates
 	- habannalabs driver updates
 	- virtual acrn driver addition (proper acks from the x86
 	  maintainers)
 	- broadcom misc driver addition
 	- speakup driver updates
 	- soundwire driver updates
 	- fpga driver updates
 	- amba driver updates
 	- mei driver updates
 	- vfio driver updates
 	- greybus driver updates
 	- nvmeem driver updates
 	- phy driver updates
 	- mhi driver updates
 	- interconnect driver udpates
 	- fsl-mc bus driver updates
 	- random driver fix
 	- some small misc driver updates (rtsx, pvpanic, etc.)
 
 All of these have been in linux-next for a while, with the only reported
 issue being a merge conflict in include/linux/mod_devicetable.h that you
 will hit in your tree due to the dfl_device_id addition from the fpga
 subsystem in here.  The resolution should be simple.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the large set of char/misc/whatever driver subsystem updates
  for 5.12-rc1. Over time it seems like this tree is collecting more and
  more tiny driver subsystems in one place, making it easier for those
  maintainers, which is why this is getting larger.

  Included in here are:

   - coresight driver updates

   - habannalabs driver updates

   - virtual acrn driver addition (proper acks from the x86 maintainers)

   - broadcom misc driver addition

   - speakup driver updates

   - soundwire driver updates

   - fpga driver updates

   - amba driver updates

   - mei driver updates

   - vfio driver updates

   - greybus driver updates

   - nvmeem driver updates

   - phy driver updates

   - mhi driver updates

   - interconnect driver udpates

   - fsl-mc bus driver updates

   - random driver fix

   - some small misc driver updates (rtsx, pvpanic, etc.)

  All of these have been in linux-next for a while, with the only
  reported issue being a merge conflict due to the dfl_device_id
  addition from the fpga subsystem in here"

* tag 'char-misc-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (311 commits)
  spmi: spmi-pmic-arb: Fix hw_irq overflow
  Documentation: coresight: Add PID tracing description
  coresight: etm-perf: Support PID tracing for kernel at EL2
  coresight: etm-perf: Clarify comment on perf options
  ACRN: update MAINTAINERS: mailing list is subscribers-only
  regmap: sdw-mbq: use MODULE_LICENSE("GPL")
  regmap: sdw: use no_pm routines for SoundWire 1.2 MBQ
  regmap: sdw: use _no_pm functions in regmap_read/write
  soundwire: intel: fix possible crash when no device is detected
  MAINTAINERS: replace my with email with replacements
  mhi: Fix double dma free
  uapi: map_to_7segment: Update example in documentation
  uio: uio_pci_generic: don't fail probe if pdev->irq equals to IRQ_NOTCONNECTED
  drivers/misc/vmw_vmci: restrict too big queue size in qp_host_alloc_queue
  firewire: replace tricky statement by two simple ones
  vme: make remove callback return void
  firmware: google: make coreboot driver's remove callback return void
  firmware: xilinx: Use explicit values for all enum values
  sample/acrn: Introduce a sample of HSM ioctl interface usage
  virt: acrn: Introduce an interface for Service VM to control vCPU
  ...
2021-02-24 10:25:37 -08:00
Linus Torvalds
21a6ab2131 Modules updates for v5.12
Summary of modules changes for the 5.12 merge window:
 
 - Retire EXPORT_UNUSED_SYMBOL() and EXPORT_SYMBOL_GPL_FUTURE(). These export
   types were introduced between 2006 - 2008. All the of the unused symbols have
   been long removed and gpl future symbols were converted to gpl quite a long
   time ago, and I don't believe these export types have been used ever since.
   So, I think it should be safe to retire those export types now. (Christoph Hellwig)
 
 - Refactor and clean up some aged code cruft in the module loader (Christoph Hellwig)
 
 - Build {,module_}kallsyms_on_each_symbol only when livepatching is enabled, as
   it is the only caller (Christoph Hellwig)
 
 - Unexport find_module() and module_mutex and fix the last module
   callers to not rely on these anymore. Make module_mutex internal to
   the module loader. (Christoph Hellwig)
 
 - Harden ELF checks on module load and validate ELF structures before checking
   the module signature (Frank van der Linden)
 
 - Fix undefined symbol warning for clang (Fangrui Song)
 
 - Fix smatch warning (Dan Carpenter)
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull module updates from Jessica Yu:

 - Retire EXPORT_UNUSED_SYMBOL() and EXPORT_SYMBOL_GPL_FUTURE(). These
   export types were introduced between 2006 - 2008. All the of the
   unused symbols have been long removed and gpl future symbols were
   converted to gpl quite a long time ago, and I don't believe these
   export types have been used ever since. So, I think it should be safe
   to retire those export types now (Christoph Hellwig)

 - Refactor and clean up some aged code cruft in the module loader
   (Christoph Hellwig)

 - Build {,module_}kallsyms_on_each_symbol only when livepatching is
   enabled, as it is the only caller (Christoph Hellwig)

 - Unexport find_module() and module_mutex and fix the last module
   callers to not rely on these anymore. Make module_mutex internal to
   the module loader (Christoph Hellwig)

 - Harden ELF checks on module load and validate ELF structures before
   checking the module signature (Frank van der Linden)

 - Fix undefined symbol warning for clang (Fangrui Song)

 - Fix smatch warning (Dan Carpenter)

* tag 'modules-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: potential uninitialized return in module_kallsyms_on_each_symbol()
  module: remove EXPORT_UNUSED_SYMBOL*
  module: remove EXPORT_SYMBOL_GPL_FUTURE
  module: move struct symsearch to module.c
  module: pass struct find_symbol_args to find_symbol
  module: merge each_symbol_section into find_symbol
  module: remove each_symbol_in_section
  module: mark module_mutex static
  kallsyms: only build {,module_}kallsyms_on_each_symbol when required
  kallsyms: refactor {,module_}kallsyms_on_each_symbol
  module: use RCU to synchronize find_module
  module: unexport find_module and module_mutex
  drm: remove drm_fb_helper_modinit
  powerpc/powernv: remove get_cxl_module
  module: harden ELF info handling
  module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
2021-02-23 10:15:33 -08:00
Linus Torvalds
79db4d2293 clang-lto series for v5.12-rc1
- Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen)
 - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)
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Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO updates from Kees Cook:
 "Clang Link Time Optimization.

  This is built on the work done preparing for LTO by arm64 folks,
  tracing folks, etc. This includes the core changes as well as the
  remaining pieces for arm64 (LTO has been the default build method on
  Android for about 3 years now, as it is the prerequisite for the
  Control Flow Integrity protections).

  While x86 LTO enablement is done, it depends on some pending objtool
  clean-ups. It's possible that I'll send a "part 2" pull request for
  LTO that includes x86 support.

  For merge log posterity, and as detailed in commit dc5723b02e
  ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
  build:

        make LLVM=1 LLVM_IAS=1 defconfig
        scripts/config -e LTO_CLANG_THIN
        make LLVM=1 LLVM_IAS=1

  (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
  and "ARCH=arm64" to the "make" command lines.)

  Summary:

   - Clang LTO build infrastructure and arm64-specific enablement (Sami
     Tolvanen)

   - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"

* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
  arm64: allow LTO to be selected
  arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
  arm64: vdso: disable LTO
  drivers/misc/lkdtm: disable LTO for rodata.o
  efi/libstub: disable LTO
  scripts/mod: disable LTO for empty.c
  modpost: lto: strip .lto from module names
  PCI: Fix PREL32 relocations for LTO
  init: lto: fix PREL32 relocations
  init: lto: ensure initcall ordering
  kbuild: lto: add a default list of used symbols
  kbuild: lto: merge module sections
  kbuild: lto: limit inlining
  kbuild: lto: fix module versioning
  kbuild: add support for Clang LTO
  tracing: move function tracer options to Kconfig
2021-02-23 09:28:51 -08:00
Christoph Hellwig
367948220f module: remove EXPORT_UNUSED_SYMBOL*
EXPORT_UNUSED_SYMBOL* is not actually used anywhere.  Remove the
unused functionality as we generally just remove unused code anyway.

Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-02-08 12:28:07 +01:00
Christoph Hellwig
f1c3d73e97 module: remove EXPORT_SYMBOL_GPL_FUTURE
As far as I can tell this has never been used at all, and certainly
not any time recently.

Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-02-08 12:28:02 +01:00
Sami Tolvanen
d23dddf86a scripts/mod: disable LTO for empty.c
With CONFIG_LTO_CLANG, clang generates LLVM IR instead of ELF object
files. As empty.o is used for probing target properties, disable LTO
for it to produce an object file instead.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-12-samitolvanen@google.com
2021-01-14 08:21:09 -08:00
Sami Tolvanen
7ac204b545 modpost: lto: strip .lto from module names
With LTO, everything is compiled into LLVM bitcode, so we have to link
each module into native code before modpost. Kbuild uses the .lto.o
suffix for these files, which also ends up in module information. This
change strips the unnecessary .lto suffix from the module name.

Suggested-by: Bill Wendling <morbo@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-11-samitolvanen@google.com
2021-01-14 08:21:09 -08:00
Xu Yilun
4a224acec5 fpga: dfl: add dfl bus support to MODULE_DEVICE_TABLE()
Device Feature List (DFL) is a linked list of feature headers within the
device MMIO space. It is used by FPGA to enumerate multiple sub features
within it. Each feature can be uniquely identified by DFL type and
feature id, which can be read out from feature headers.

A dfl bus helps DFL framework modularize DFL device drivers for
different sub features. The dfl bus matches its devices and drivers by
DFL type and feature id.

This patch adds dfl bus support to MODULE_DEVICE_TABLE() by adding info
about struct dfl_device_id in devicetable-offsets.c and add a dfl entry
point in file2alias.c.

Acked-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Link: https://lore.kernel.org/r/20210107043714.991646-6-mdf@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07 15:21:27 +01:00
Maximilian Luz
eb0e90a820 platform/surface: aggregator: Add dedicated bus and device type
The Surface Aggregator EC provides varying functionality, depending on
the Surface device. To manage this functionality, we use dedicated
client devices for each subsystem or virtual device of the EC. While
some of these clients are described as standard devices in ACPI and the
corresponding client drivers can be implemented as platform drivers in
the kernel (making use of the controller API already present), many
devices, especially on newer Surface models, cannot be found there.

To simplify management of these devices, we introduce a new bus and
client device type for the Surface Aggregator subsystem. The new device
type takes care of managing the controller reference, essentially
guaranteeing its validity for as long as the client device exists, thus
alleviating the need to manually establish device links for that purpose
in the client driver (as has to be done with the platform devices).

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201221183959.1186143-7-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2021-01-07 00:06:39 +01:00
Linus Torvalds
7b95f0563a Kbuild updates for v5.11
- Use /usr/bin/env for shebang lines in scripts
 
  - Remove useless -Wnested-externs warning flag
 
  - Update documents
 
  - Refactor log handling in modpost
 
  - Stop building modules without MODULE_LICENSE() tag
 
  - Make the insane combination of 'static' and EXPORT_SYMBOL an error
 
  - Improve genksyms to handle _Static_assert()
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Merge tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Use /usr/bin/env for shebang lines in scripts

 - Remove useless -Wnested-externs warning flag

 - Update documents

 - Refactor log handling in modpost

 - Stop building modules without MODULE_LICENSE() tag

 - Make the insane combination of 'static' and EXPORT_SYMBOL an error

 - Improve genksyms to handle _Static_assert()

* tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Documentation/kbuild: Document platform dependency practises
  Documentation/kbuild: Document COMPILE_TEST dependencies
  genksyms: Ignore module scoped _Static_assert()
  modpost: turn static exports into error
  modpost: turn section mismatches to error from fatal()
  modpost: change license incompatibility to error() from fatal()
  modpost: turn missing MODULE_LICENSE() into error
  modpost: refactor error handling and clarify error/fatal difference
  modpost: rename merror() to error()
  kbuild: don't hardcode depmod path
  kbuild: doc: document subdir-y syntax
  kbuild: doc: clarify the difference between extra-y and always-y
  kbuild: doc: split if_changed explanation to a separate section
  kbuild: doc: merge 'Special Rules' and 'Custom kbuild commands' sections
  kbuild: doc: fix 'List directories to visit when descending' section
  kbuild: doc: replace arch/$(ARCH)/ with arch/$(SRCARCH)/
  kbuild: doc: update the description about kbuild Makefiles
  Makefile.extrawarn: remove -Wnested-externs warning
  tweewide: Fix most Shebang lines
2020-12-22 14:02:39 -08:00
Quentin Perret
b9ed847b5a modpost: turn static exports into error
Using EXPORT_SYMBOL*() on static functions is fundamentally wrong.
Modpost currently reports that as a warning, but clearly this is not a
pattern we should allow, and all in-tree occurences should have been
fixed by now. So, promote the warn() message to error() to make sure
this never happens again.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21 13:57:08 +09:00
Masahiro Yamada
c7299d98c0 modpost: turn section mismatches to error from fatal()
There is code that reports static EXPORT_SYMBOL a few lines below.
It is not a good idea to bail out here.

I renamed sec_mismatch_fatal to sec_mismatch_warn_only (with logical
inversion) to match to CONFIG_SECTION_MISMATCH_WARN_ONLY.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21 13:57:08 +09:00
Masahiro Yamada
d6d692fa21 modpost: change license incompatibility to error() from fatal()
Change fatal() to error() to continue running to report more possible
issues.

There is no difference in the fact that modpost will fail anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21 13:57:08 +09:00
Masahiro Yamada
1d6cd39293 modpost: turn missing MODULE_LICENSE() into error
Do not create modules with no license tag.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21 13:57:08 +09:00
Masahiro Yamada
0fd3fbadd9 modpost: refactor error handling and clarify error/fatal difference
We have 3 log functions. fatal() is special because it lets modpost bail
out immediately. The difference between warn() and error() is the only
prefix parts ("WARNING:" vs "ERROR:").

In my understanding, the expected handling of error() is to propagate
the return code of the function to the exit code of modpost, as
check_exports() etc. already does. This is a good manner in general
because we should display as many error messages as possible in a
single run of modpost.

What is annoying about fatal() is that it kills modpost at the first
error. People would need to run Kbuild again and again until they fix
all errors.

But, unfortunately, people tend to do:
"This case should not be allowed. Let's replace warn() with fatal()."

One of the reasons is probably it is tedious to manually hoist the error
code to the main() function.

This commit refactors error() so any single call for it automatically
makes modpost return the error code.

I also added comments in modpost.h for warn(), error(), and fatal().

Please use fatal() only when you have a strong reason to do so.
For example:

  - Memory shortage (i.e. malloc() etc. has failed)
  - The ELF file is broken, and there is no point to continue parsing
  - Something really odd has happened

For general coding errors, please use error().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Quentin Perret <qperret@google.com>
2020-12-21 13:57:08 +09:00
Masahiro Yamada
bc72d723ec modpost: rename merror() to error()
The log function names, warn(), merror(), fatal() are inconsistent.

Commit 2a11665945 ("kbuild: distinguish between errors and warnings
in modpost") intentionally chose merror() to avoid the conflict with
the library function error(). See man page of error(3).

But, we are already causing the conflict with warn() because it is also
a library function. See man page of warn(3). err() would be a problem
for the same reason.

The common technique to work around name conflicts is to use macros.
For example:

    /* in a header */
    #define error(fmt, ...)  __error(fmt, ##__VA_ARGS__)
    #define warn(fmt, ...)   __warn(fmt, ##__VA_ARGS__)

    /* function definition */
    void __error(const char *fmt, ...)
    {
            <our implementation>
    }

    void __warn(const char *fmt, ...)
    {
            <our implementation>
    }

In this way, we can implement our own warn() and error(), still we can
include <error.h> and <err.h> with no problem.

And, commit 93c95e526a ("modpost: rework and consolidate logging
interface") already did that.

Since the log functions are all macros, we can use error() without
causing "conflicting types" errors.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21 13:57:08 +09:00
Dave Ertman
7de3697e9c Add auxiliary bus support
Add support for the Auxiliary Bus, auxiliary_device and auxiliary_driver.
It enables drivers to create an auxiliary_device and bind an
auxiliary_driver to it.

The bus supports probe/remove shutdown and suspend/resume callbacks.
Each auxiliary_device has a unique string based id; driver binds to
an auxiliary_device based on this id through the bus.

Co-developed-by: Kiran Patil <kiran.patil@intel.com>
Co-developed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Co-developed-by: Fred Oh <fred.oh@linux.intel.com>
Co-developed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Fred Oh <fred.oh@linux.intel.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Martin Habets <mhabets@solarflare.com>
Link: https://lore.kernel.org/r/20201113161859.1775473-2-david.m.ertman@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/160695681289.505290.8978295443574440604.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-04 12:23:25 +01:00
Joe Perches
33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Linus Torvalds
fc80c51fd4 Kbuild updates for v5.9
- run the checker (e.g. sparse) after the compiler
 
  - remove unneeded cc-option tests for old compiler flags
 
  - fix tar-pkg to install dtbs
 
  - introduce ccflags-remove-y and asflags-remove-y syntax
 
  - allow to trace functions in sub-directories of lib/
 
  - introduce hostprogs-always-y and userprogs-always-y syntax
 
  - various Makefile cleanups
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Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler
2020-08-09 14:10:26 -07:00
Masahiro Yamada
faabed295c kbuild: introduce hostprogs-always-y and userprogs-always-y
To build host programs, you need to add the program names to 'hostprogs'
to use the necessary build rule, but it is not enough to build them
because there is no dependency.

There are two types of host programs: built as the prerequisite of
another (e.g. gen_crc32table in lib/Makefile), or always built when
Kbuild visits the Makefile (e.g. genksyms in scripts/genksyms/Makefile).

The latter is typical in Makefiles under scripts/, which contains host
programs globally used during the kernel build. To build them, you need
to add them to both 'hostprogs' and 'always-y'.

This commit adds hostprogs-always-y as a shorthand.

The same applies to user programs. net/bpfilter/Makefile builds
bpfilter_umh on demand, hence always-y is unneeded. In contrast,
programs under samples/ are added to both 'userprogs' and 'always-y'
so they are always built when Kbuild visits the Makefiles.

userprogs-always-y works as a shorthand.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2020-08-10 01:32:59 +09:00
Linus Torvalds
1785d11612 Char/Misc driver patches for 5.9-rc1
Here is the large set of char and misc and other driver subsystem
 patches for 5.9-rc1.  Lots of new driver submissions in here, and
 cleanups and features for existing drivers.
 
 Highlights are:
 	- habanalabs driver updates
 	- coresight driver updates
 	- nvmem driver updates
 	- huge number of "W=1" build warning cleanups from Lee Jones
 	- dyndbg updates
 	- virtbox driver fixes and updates
 	- soundwire driver updates
 	- mei driver updates
 	- phy driver updates
 	- fpga driver updates
 	- lots of smaller individual misc/char driver cleanups and fixes
 
 Full details are in the shortlog.
 
 All of these have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the large set of char and misc and other driver subsystem
  patches for 5.9-rc1. Lots of new driver submissions in here, and
  cleanups and features for existing drivers.

  Highlights are:
   - habanalabs driver updates
   - coresight driver updates
   - nvmem driver updates
   - huge number of "W=1" build warning cleanups from Lee Jones
   - dyndbg updates
   - virtbox driver fixes and updates
   - soundwire driver updates
   - mei driver updates
   - phy driver updates
   - fpga driver updates
   - lots of smaller individual misc/char driver cleanups and fixes

  Full details are in the shortlog.

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (322 commits)
  habanalabs: remove unused but set variable 'ctx_asid'
  nvmem: qcom-spmi-sdam: Enable multiple devices
  dt-bindings: nvmem: SID: add binding for A100's SID controller
  nvmem: update Kconfig description
  nvmem: qfprom: Add fuse blowing support
  dt-bindings: nvmem: Add properties needed for blowing fuses
  dt-bindings: nvmem: qfprom: Convert to yaml
  nvmem: qfprom: use NVMEM_DEVID_AUTO for multiple instances
  nvmem: core: add support to auto devid
  nvmem: core: Add nvmem_cell_read_u8()
  nvmem: core: Grammar fixes for help text
  nvmem: sc27xx: add sc2730 efuse support
  nvmem: Enforce nvmem stride in the sysfs interface
  MAINTAINERS: Add git tree for NVMEM FRAMEWORK
  nvmem: sprd: Fix return value of sprd_efuse_probe()
  drivers: android: Fix the SPDX comment style
  drivers: android: Fix a variable declaration coding style issue
  drivers: android: Remove braces for a single statement if-else block
  drivers: android: Remove the use of else after return
  drivers: android: Fix a variable declaration coding style issue
  ...
2020-08-05 11:43:47 -07:00
Greg Kroah-Hartman
65a9bde6ed Linux 5.8-rc7
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Merge 5.8-rc7 into char-misc-next

This should resolve the merge/build issues reported when trying to
create linux-next.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-27 11:49:37 +02:00
Wolfram Sang
6020db504c modpost: explain why we can't use strsep
Mention why we open-code strsep, so it is clear that it is intentional.

Fixes: 736bb11898 ("modpost: remove use of non-standard strsep() in HOSTCC code")
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-07-27 13:38:38 +09:00
H. Nikolaus Schaller
736bb11898 modpost: remove use of non-standard strsep() in HOSTCC code
strsep() is neither standard C nor POSIX and used outside
the kernel code here. Using it here requires that the
build host supports it out of the box which is e.g.
not true for a Darwin build host and using a cross-compiler.
This leads to:

scripts/mod/modpost.c:145:2: warning: implicit declaration of function 'strsep' [-Wimplicit-function-declaration]
  return strsep(stringp, "\n");
  ^

and a segfault when running MODPOST.

See also: https://stackoverflow.com/a/7219504

So let's replace this by strchr() instead of using strsep().
It does not hurt kernel size or speed since this code is run
on the build host.

Fixes: ac5100f543 ("modpost: add read_text_file() and get_line() helpers")
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-07-07 11:21:00 +09:00
Pierre-Louis Bossart
b5924268d6 soundwire: extend SDW_SLAVE_ENTRY
The SoundWire 1.2 specification adds new capabilities that were not
present in previous version, such as the class ID.

To enable support for class drivers, and well as drivers that address
a specific version, all fields of the sdw_device_id structure need to
be exposed. For SoundWire 1.0 and 1.1 devices, a wildcard is used so
class and version information are ignored.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200608205436.2402-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-06-30 21:26:17 +05:30
Linus Torvalds
cff11abeca Kbuild updates for v5.8
- fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32
 
  - ensure to rebuild all objects when the compiler is upgraded
 
  - exclude system headers from dependency tracking and fixdep processing
 
  - fix potential bit-size mismatch between the kernel and BPF user-mode
    helper
 
  - add the new syntax 'userprogs' to build user-space programs for the
    target architecture (the same arch as the kernel)
 
  - compile user-space sample code under samples/ for the target arch
    instead of the host arch
 
  - make headers_install fail if a CONFIG option is leaked to user-space
 
  - sanitize the output format of scripts/checkstack.pl
 
  - handle ARM 'push' instruction in scripts/checkstack.pl
 
  - error out before modpost if a module name conflict is found
 
  - error out when multiple directories are passed to M= because this
    feature is broken for a long time
 
  - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info
 
  - a lot of cleanups of modpost
 
  - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
    second pass of modpost
 
  - do not run the second pass of modpost if nothing in modules is updated
 
  - install modules.builtin(.modinfo) by 'make install' as well as by
    'make modules_install' because it is useful even when CONFIG_MODULES=n
 
  - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
    to allow users to use alternatives such as pigz, pbzip2, etc.
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Merge tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32

 - ensure to rebuild all objects when the compiler is upgraded

 - exclude system headers from dependency tracking and fixdep processing

 - fix potential bit-size mismatch between the kernel and BPF user-mode
   helper

 - add the new syntax 'userprogs' to build user-space programs for the
   target architecture (the same arch as the kernel)

 - compile user-space sample code under samples/ for the target arch
   instead of the host arch

 - make headers_install fail if a CONFIG option is leaked to user-space

 - sanitize the output format of scripts/checkstack.pl

 - handle ARM 'push' instruction in scripts/checkstack.pl

 - error out before modpost if a module name conflict is found

 - error out when multiple directories are passed to M= because this
   feature is broken for a long time

 - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info

 - a lot of cleanups of modpost

 - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
   second pass of modpost

 - do not run the second pass of modpost if nothing in modules is
   updated

 - install modules.builtin(.modinfo) by 'make install' as well as by
   'make modules_install' because it is useful even when
   CONFIG_MODULES=n

 - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
   to allow users to use alternatives such as pigz, pbzip2, etc.

* tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits)
  kbuild: add variables for compression tools
  Makefile: install modules.builtin even if CONFIG_MODULES=n
  mksysmap: Fix the mismatch of '.L' symbols in System.map
  kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS
  modpost: change elf_info->size to size_t
  modpost: remove is_vmlinux() helper
  modpost: strip .o from modname before calling new_module()
  modpost: set have_vmlinux in new_module()
  modpost: remove mod->skip struct member
  modpost: add mod->is_vmlinux struct member
  modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
  modpost: remove mod->is_dot_o struct member
  modpost: move -d option in scripts/Makefile.modpost
  modpost: remove -s option
  modpost: remove get_next_text() and make {grab,release_}file static
  modpost: use read_text_file() and get_line() for reading text files
  modpost: avoid false-positive file open error
  modpost: fix potential mmap'ed file overrun in get_src_version()
  modpost: add read_text_file() and get_line() helpers
  modpost: do not call get_modinfo() for vmlinux(.o)
  ...
2020-06-06 12:00:25 -07:00
Linus Torvalds
e542e0dc3e Merge branch 'dmi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
Pull dmi update from Jean Delvare.

* 'dmi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  firmware/dmi: Report DMI Bios & EC firmware release
2020-06-06 11:30:00 -07:00
Masahiro Yamada
3b09efc4f0 modpost: change elf_info->size to size_t
Align with the mmap / munmap APIs.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:39:20 +09:00
Masahiro Yamada
4de7b62936 modpost: remove is_vmlinux() helper
Now that is_vmlinux() is called only in new_module(), we can inline
the function call.

modname is the basename with '.o' is stripped. No need to compare it
with 'vmlinux.o'.

vmlinux is always located at the current working directory. No need
to strip the directory path.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:39:20 +09:00
Masahiro Yamada
a82f794c41 modpost: strip .o from modname before calling new_module()
new_module() conditionally strips the .o because the modname has .o
suffix when it is called from read_symbols(), but no .o when it is
called from read_dump().

It is clearer to strip .o in read_symbols().

I also used flexible-array for mod->name.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:39:20 +09:00
Masahiro Yamada
858b937d28 modpost: set have_vmlinux in new_module()
Set have_vmlinux flag in a single place.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:39:20 +09:00
Masahiro Yamada
0b19d54cae modpost: remove mod->skip struct member
The meaning of 'skip' is obscure since it does not explain
"what to skip".

mod->skip is set when it is vmlinux or the module info came from
a dump file.

So, mod->skip is equivalent to (mod->is_vmlinux || mod->from_dump).

For the check in write_namespace_deps_files(), mod->is_vmlinux is
unneeded because the -d option is not passed in the first pass of
modpost.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:39:20 +09:00
Masahiro Yamada
5a438af9db modpost: add mod->is_vmlinux struct member
is_vmlinux() is called in several places to check whether the current
module is vmlinux or not.

It is faster and clearer to check mod->is_vmlinux flag.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:39:19 +09:00
Masahiro Yamada
1be5fa6c94 modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
check_exports() is never called for vmlinux because mod->skip is set
for vmlinux.

Hence, check_for_gpl_usage() and check_for_unused() are not called
for vmlinux, either. is_vmlinux() is always false here.

Remove the is_vmlinux() calls, and hard-code the ".ko" suffix.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00
Masahiro Yamada
3379576dd6 modpost: remove mod->is_dot_o struct member
Previously, there were two cases where mod->is_dot_o is unset:

[1] the executable 'vmlinux' in the second pass of modpost
[2] modules loaded by read_dump()

I think [1] was intended usage to distinguish 'vmlinux.o' and 'vmlinux'.
Now that modpost does not parse the executable 'vmlinux', this case
does not happen.

[2] is obscure, maybe a bug. Module.symver stores module paths without
extension. So, none of modules loaded by read_dump() has the .o suffix,
and new_module() unsets ->is_dot_o. Anyway, it is not a big deal because
handle_symbol() is not called for the case.

To sum up, all the parsed ELF files are .o files.

mod->is_dot_o is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00
Masahiro Yamada
467b82d7ce modpost: remove -s option
The -s option was added by commit 8d8d8289df ("kbuild: do not do
section mismatch checks on vmlinux in 2nd pass").

Now that the second pass does not parse vmlinux, this option is
unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00
Masahiro Yamada
75893572d4 modpost: remove get_next_text() and make {grab,release_}file static
get_next_line() is no longer used. Remove.

grab_file() and release_file() are only used in modpost.c. Make them
static.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00
Masahiro Yamada
70f30cfe5b modpost: use read_text_file() and get_line() for reading text files
grab_file() mmaps a file, but it is not so efficient here because
get_next_line() copies every line to the temporary buffer anyway.

read_text_file() and get_line() are simpler. get_line() exploits the
library function strchr().

Going forward, the missing *.symvers or *.cmd is a fatal error.
This should not happen because scripts/Makefile.modpost guards the
-i option files with $(wildcard $(input-symdump)).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00
Masahiro Yamada
7c8f5662c5 modpost: avoid false-positive file open error
One problem of grab_file() is that it cannot distinguish the following
two cases:

 - It cannot read the file (the file does not exist, or read permission
   is not set)

 - It can read the file, but the file size is zero

This is because grab_file() calls mmap(), which requires the mapped
length is greater than 0. Hence, grab_file() fails for both cases.

If an empty header file were included for checksum calculation, the
following warning would be printed:

  WARNING: modpost: could not open ...: Invalid argument

An empty file is a valid source file, so it should not fail.

Use read_text_file() instead. It can read a zero-length file.
Then, parse_file() will succeed with doing nothing.

Going forward, the first case (it cannot read the file) is a fatal
error. If the source file from which an object was compiled is missing,
something went wrong.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00