Commit Graph

131 Commits

Author SHA1 Message Date
Yueh-Shun Li
19ee69234a um: Makefile: use bash from the environment
Set Makefile SHELL to bash instead of /bin/bash for better portability.

Some systems do not install binaries to /bin, and therefore do not
provide /bin/bash. This includes Linux distros which intentionally avoid
implementing the Filesystem Hierarchy Standard (FHS), such as NixOS and
Guix System.

The recipies inside arch/um/Makefile don't require top-level Bash to
build, and setting "SHELL" to "bash" makes Make pick the Bash executable
from the environment, hence this patch.

Changes since last roll:
- Rebase onto a more recent commit on the master branch.
- Remove a dangling in-text citation from the change log.
- Reword the change log.

Signed-off-by: Yueh-Shun Li <shamrocklee@posteo.net>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-22 22:17:29 +02:00
Nathan Chancellor
846cfbeed0 um: Fix adding '-no-pie' for clang
The kernel builds with -fno-PIE, so commit 883354afbc ("um: link
vmlinux with -no-pie") added the compiler linker flag '-no-pie' via
cc-option because '-no-pie' was only supported in GCC 6.1.0 and newer.

While this works for GCC, this does not work for clang because cc-option
uses '-c', which stops the pipeline right before linking, so '-no-pie'
is unconsumed and clang warns, causing cc-option to fail just as it
would if the option was entirely unsupported:

  $ clang -Werror -no-pie -c -o /dev/null -x c /dev/null
  clang-16: error: argument unused during compilation: '-no-pie' [-Werror,-Wunused-command-line-argument]

A recent version of clang exposes this because it generates a relocation
under '-mcmodel=large' that is not supported in PIE mode:

  /usr/sbin/ld: init/main.o: relocation R_X86_64_32 against symbol `saved_command_line' can not be used when making a PIE object; recompile with -fPIE
  /usr/sbin/ld: failed to set dynamic section sizes: bad value
  clang: error: linker command failed with exit code 1 (use -v to see invocation)

Remove the cc-option check altogether. It is wasteful to invoke the
compiler to check for '-no-pie' because only one supported compiler
version does not support it, GCC 5.x (as it is supported with the
minimum version of clang and GCC 6.1.0+). Use a combination of the
gcc-min-version macro and CONFIG_CC_IS_CLANG to unconditionally add
'-no-pie' with CONFIG_LD_SCRIPT_DYN=y, so that it is enabled with all
compilers that support this. Furthermore, using gcc-min-version can help
turn this back into

  LINK-$(CONFIG_LD_SCRIPT_DYN) += -no-pie

when the minimum version of GCC is bumped past 6.1.0.

Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/1982
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-01-28 01:13:37 +09:00
Masahiro Yamada
8f85f93bfd um: use obj-y to descend into arch/um/*/
The single build rule does not work with the core-y syntax. [1]

Use the standard obj-y syntax.

[1]: https://lore.kernel.org/linux-kbuild/d57ba55f-20a3-b836-783d-b49c8a161b6e@kernel.org/T/#m7bc402e1e038f00ebcf2e92ed7fcb8a52fc1ea44

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-08-26 22:41:34 +02:00
Masahiro Yamada
d32df1080f um: Hard-code the result of 'uname -s'
We rely on 'uname -s' returning 'Linux' because there are os-Linux/
directories, but no other os-*/.

Supporting a non-Linux host is unlikely to happen.

Let's hard-code 'Linux'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-08-26 22:40:37 +02:00
Kees Cook
a5a319ec2c um: Use HOST_DIR for mrproper
When HEADER_ARCH was introduced, the MRPROPER_FILES (then MRPROPER_DIRS)
list wasn't adjusted, leaving SUBARCH as part of the path argument.
This resulted in the "mrproper" target not cleaning up arch/x86/... when
SUBARCH was specified. Since HOST_DIR is arch/$(HEADER_ARCH), use it
instead to get the correct path.

Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: linux-um@lists.infradead.org
Fixes: 7bbe7204e9 ("um: merge Makefile-{i386,x86_64}")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230606222442.never.807-kees@kernel.org
2023-06-14 12:27:38 -07:00
Peter Foley
83e913f52a um: Support LTO
Only a handful of changes are necessary to get it to work.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-02-13 10:14:31 +01:00
Peter Foley
6aa56115c7 um: Use CFLAGS_vmlinux
link-vmlinux.sh doesn't use LDFLAGS_vmlinux when linking the kernel for
UML. Move the LDFLAGS_EXESTACK options into CFLAGS_vmlinux so they're
actually respected.

e.g.
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: warning: .tmp_vmlinux.kallsyms3.o: missing .note.GNU-stack section implies executable stack
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: warning: vmlinux has a LOAD segment with RWX permissions

Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-02-13 10:14:20 +01:00
David Gow
905a770775 rust: arch/um: Use 'pie' relocation mode under UML
UML expects a position independent executable for some reason, so tell
rustc to generate pie objects. Otherwise we get a bunch of relocations
we can't deal with in libcore.

Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-02-10 21:27:32 +01:00
David Gow
bd71558d58 arch: um: Mark the stack non-executable to fix a binutils warning
Since binutils 2.39, ld will print a warning if any stack section is
executable, which is the default for stack sections on files without a
.note.GNU-stack section.

This was fixed for x86 in commit ffcf9c5700 ("x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments"),
but remained broken for UML, resulting in several warnings:

/usr/bin/ld: warning: arch/x86/um/vdso/vdso.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms1 has a LOAD segment with RWX permissions
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms1.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms2 has a LOAD segment with RWX permissions
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms2.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: vmlinux has a LOAD segment with RWX permissions

Link both the VDSO and vmlinux with -z noexecstack, fixing the warnings
about .note.GNU-stack sections. In addition, pass --no-warn-rwx-segments
to dodge the remaining warnings about LOAD segments with RWX permissions
in the kallsyms objects. (Note that this flag is apparently not
available on lld, so hide it behind a test for BFD, which is what the
x86 patch does.)

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ffcf9c5700e49c0aee42dcba9a12ba21338e8136
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-09-21 09:11:42 +02:00
Nathan Chancellor
1e39036de5 Revert "um: clang: Strip out -mno-global-merge from USER_CFLAGS"
This reverts commit 6580c5c18f.

This patch is buggy, as noted in the patch linked below. The root cause
has been solved by removing '-mno-global-merge' for the entire kernel.

Link: https://lore.kernel.org/r/20220322173547.677760-1-nathan@kernel.org/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-04-02 00:05:28 +09:00
David Gow
6580c5c18f um: clang: Strip out -mno-global-merge from USER_CFLAGS
The things built with USER_CFLAGS don't seem to recognise it as a
compiler option, and print a warning:
clang: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument]

Fixes: 744814d2fa ("um: Allow builds with Clang")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-03-11 10:51:41 +01:00
Masahiro Yamada
d828563955 kbuild: do not require sub-make for separate output tree builds
As explained in commit 3204a7fb98 ("kbuild: prefix $(srctree)/ to some
included Makefiles"), I want to stop using --include-dir some day.

I already fixed up the top Makefile, but some arch Makefiles (mips, um,
x86) still include check-in Makefiles without $(srctree)/.

Fix them up so 'need-sub-make := 1' can go away for this case.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-10 08:23:39 +09:00
Johannes Berg
386093c68b um: allow not setting extra rpaths in the linux binary
There doesn't seem to be any reason for the rpath being set in
the binaries, at on systems that I tested on. On the other hand,
setting rpath is actually harming binaries in some cases, e.g.
if using nix-based compilation environments where /lib & /lib64
are not part of the actual environment.

Add a new Kconfig option (under EXPERT, for less user confusion)
that allows disabling the rpath additions.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-06-17 21:54:15 +02:00
Masahiro Yamada
893ab00439 kbuild: remove cc-option test of -fno-stack-protector
Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.

GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)

Get rid of cc-option from -fno-stack-protector.

Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.

Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-07-07 11:13:10 +09:00
Masahiro Yamada
0663c68c4d kbuild: remove {CLEAN,MRPROPER,DISTCLEAN}_DIRS
Merge {CLEAN,MRPROPER,DISTCLEAN}_DIRS into {CLEAN,MRPROPER,DISTCLEAN}_FILES
because the difference is just the -r option passed to the 'rm' command.

Do likewise as commit 1634f2bfdb ("kbuild: remove clean-dirs syntax").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-26 00:03:15 +09:00
Vitor Massaru Iha
63ec90f182 um: ensure make ARCH=um mrproper removes arch/$(SUBARCH)/include/generated/
In this workflow:

$ make ARCH=um defconfig && make ARCH=um -j8
  [snip]
$ make ARCH=um mrproper
  [snip]
$ make ARCH=um defconfig O=./build_um && make ARCH=um -j8 O=./build_um
  [snip]
  CC      scripts/mod/empty.o
In file included from ../include/linux/types.h:6,
                 from ../include/linux/mod_devicetable.h:12,
                 from ../scripts/mod/devicetable-offsets.c:3:
../include/uapi/linux/types.h:5:10: fatal error: asm/types.h: No such file or directory
    5 | #include <asm/types.h>
      |          ^~~~~~~~~~~~~
compilation terminated.
make[2]: *** [../scripts/Makefile.build💯 scripts/mod/devicetable-offsets.s] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [/home/iha/sdb/opensource/lkmp/linux-kselftest.git/Makefile:1140: prepare0] Error 2
make[1]: Leaving directory '/home/iha/sdb/opensource/lkmp/linux-kselftest.git/build_um'
make: *** [Makefile:180: sub-make] Error 2

The cause of the error was because arch/$(SUBARCH)/include/generated files
weren't properly cleaned by `make ARCH=um mrproper`.

Fixes: a788b2ed81 ("kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build")
Reported-by: Theodore Ts'o <tytso@mit.edu>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Link: https://groups.google.com/forum/#!msg/kunit-dev/QmA27YEgEgI/hvS1kiz2CwAJ
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-04-23 10:50:26 +09:00
Masahiro Yamada
75dd47472b kbuild: remove src and obj from the top Makefile
Replace $(src) and $(obj) with $(srctree) and $(objtree), respectively.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-11 00:05:09 +09:00
Masahiro Yamada
733f4ef46d um: remove unused filechk_gen_header in Makefile
This is a leftover of commit ecba97d4aa ("[PATCH] uml makefiles
sanitized").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:35:20 +09:00
Masahiro Yamada
65bba0423e kbuild: fix UML build error with CONFIG_GCC_PLUGINS
UML fails to build with CONFIG_GCC_PLUGINS=y.

$ make -s ARCH=um mrproper
$ make -s ARCH=um allmodconfig
$ make ARCH=um
  UPD     include/generated/uapi/linux/version.h
  WRAP    arch/x86/include/generated/uapi/asm/bpf_perf_event.h
  WRAP    arch/x86/include/generated/uapi/asm/poll.h
  WRAP    arch/x86/include/generated/asm/dma-contiguous.h
  WRAP    arch/x86/include/generated/asm/early_ioremap.h
  WRAP    arch/x86/include/generated/asm/export.h
  WRAP    arch/x86/include/generated/asm/mcs_spinlock.h
  WRAP    arch/x86/include/generated/asm/mm-arch-hooks.h
  SYSTBL  arch/x86/include/generated/asm/syscalls_32.h
  SYSHDR  arch/x86/include/generated/asm/unistd_32_ia32.h
  SYSHDR  arch/x86/include/generated/asm/unistd_64_x32.h
  SYSTBL  arch/x86/include/generated/asm/syscalls_64.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_32.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_64.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_x32.h
  HOSTCC  scripts/unifdef
  CC      arch/x86/um/user-offsets.s
cc1: error: cannot load plugin ./scripts/gcc-plugins/cyc_complexity_plugin.so
./scripts/gcc-plugins/cyc_complexity_plugin.so: cannot open shared object file: No such file or directory
cc1: error: cannot load plugin ./scripts/gcc-plugins/structleak_plugin.so
./scripts/gcc-plugins/structleak_plugin.so: cannot open shared object file: No such file or directory
cc1: error: cannot load plugin ./scripts/gcc-plugins/latent_entropy_plugin.so
./scripts/gcc-plugins/latent_entropy_plugin.so: cannot open shared object file: No such file or directory
cc1: error: cannot load plugin ./scripts/gcc-plugins/randomize_layout_plugin.so
./scripts/gcc-plugins/randomize_layout_plugin.so: cannot open shared object file: No such file or directory
make[1]: *** [scripts/Makefile.build;119: arch/x86/um/user-offsets.s] Error 1
make: *** [arch/um/Makefile;152: arch/x86/um/user-offsets.s] Error 2

Reorder the preparation stage (with cleanups) to make sure gcc-plugins
is built before descending to arch/x86/um/.

Fixes: 6b90bd4ba4 ("GCC plugin infrastructure")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 22:21:59 +09:00
Masahiro Yamada
d503ac531a kbuild: rename LDFLAGS to KBUILD_LDFLAGS
Commit a0f97e06a4 ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.

Commit 222d394d30 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.

Commit 06c5040cdb ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.

For some reason, LDFLAGS was not renamed.

Using a well-known variable like LDFLAGS may result in accidental
override of the variable.

Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.

I did not touch Makefiles under tools/ since the tools build system
is a different world.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-24 08:22:08 +09:00
Linus Torvalds
fa1b5d09d0 Consolidation of Kconfig files by Christoph Hellwig.
Move the source statements of arch-independent Kconfig files instead of
 duplicating the includes in every arch/$(SRCARCH)/Kconfig.
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Merge tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig consolidation from Masahiro Yamada:
 "Consolidation of Kconfig files by Christoph Hellwig.

  Move the source statements of arch-independent Kconfig files instead
  of duplicating the includes in every arch/$(SRCARCH)/Kconfig"

* tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: add a Memory Management options" menu
  kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt
  kconfig: use a menu in arch/Kconfig to reduce clutter
  kconfig: include kernel/Kconfig.preempt from init/Kconfig
  Kconfig: consolidate the "Kernel hacking" menu
  kconfig: include common Kconfig files from top-level Kconfig
  kconfig: remove duplicate SWAP symbol defintions
  um: create a proper drivers Kconfig
  um: cleanup Kconfig files
  um: stop abusing KBUILD_KCONFIG
2018-08-15 13:05:12 -07:00
Masahiro Yamada
0004438a16 um: clean up archheaders recipe
Now that '%asm-generic' is added to no-dot-config-targets,
'make asm-generic' does not include the kernel configuration.

You can simply do 'make asm-generic' in the recursed top Makefile
without bothering syncconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Richard Weinberger <richard@nod.at>
2018-08-07 21:30:36 +09:00
Masahiro Yamada
13d3d01e26 um: fix parallel building with O= option
Randy Dunlap reports UML occasionally fails to build with -j<N> and
O=<builddir> options.

  make[1]: Entering directory '/home/rdunlap/mmotm-2018-0802-1529/UM64'
    UPD     include/generated/uapi/linux/version.h
    WRAP    arch/x86/include/generated/asm/dma-contiguous.h
    WRAP    arch/x86/include/generated/asm/export.h
    WRAP    arch/x86/include/generated/asm/early_ioremap.h
    WRAP    arch/x86/include/generated/asm/mcs_spinlock.h
    WRAP    arch/x86/include/generated/asm/mm-arch-hooks.h
    WRAP    arch/x86/include/generated/uapi/asm/bpf_perf_event.h
    WRAP    arch/x86/include/generated/uapi/asm/poll.h
    GEN     ./Makefile
  make[2]: *** No rule to make target 'archheaders'.  Stop.
  arch/um/Makefile:119: recipe for target 'archheaders' failed
  make[1]: *** [archheaders] Error 2
  make[1]: *** Waiting for unfinished jobs....
    UPD     include/config/kernel.release
  make[1]: *** wait: No child processes.  Stop.
  Makefile:146: recipe for target 'sub-make' failed
  make: *** [sub-make] Error 2

The cause of the problem is the use of '$(MAKE) KBUILD_SRC=',
which recurses to the top Makefile via the $(objtree)/Makefile
generated by scripts/mkmakefile.

When you run "make -j<N> O=<builddir> ARCH=um", Make can execute
'archheaders' and 'outputmakefile' targets simultaneously because
there is no dependency between them.

If it happens,

  $(Q)$(MAKE) KBUILD_SRC= ARCH=$(HEADER_ARCH) archheaders

... tries to run $(objtree)/Makefile that is being updated.

The correct way for the recursion is

  $(Q)$(MAKE) -f $(srctree)/Makefile ARCH=$(HEADER_ARCH) archheaders

..., which does not rely on the generated Makefile.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Richard Weinberger <richard@nod.at>
2018-08-07 21:30:15 +09:00
Christoph Hellwig
79b05c1f31 um: stop abusing KBUILD_KCONFIG
Instead create a arch/um/Kconfig file that just includes the actual
per-arch Kconfig file.  Note that we use HEADER_ARCH to find the
per-arch Kconfig file as that variable already includes the
normalization from i386 or x86_64 to x86.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-02 08:03:23 +09:00
Masahiro Yamada
43fee2b238 kbuild: do not redirect the first prerequisite for filechk
Currently, filechk unconditionally opens the first prerequisite and
redirects it as the stdin of a filechk_* rule.  Hence, every target
using $(call filechk,...) must list something as the first prerequisite
even if it is unneeded.

'< $<' is actually unneeded in most cases.  Each rule can explicitly
adds it if necessary.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-28 10:34:10 +09:00
Al Viro
699d7a5734 um: make sure to have generated headers for target
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:19:51 -05:00
Thomas Meyer
883354afbc um: link vmlinux with -no-pie
Debian's gcc defaults to pie. The global Makefile already defines the -fno-pie option.
Link UML dynamic kernel image also with -no-pie to fix the build.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-09-13 22:34:30 +02:00
Florian Fainelli
f44f1e7da7 um: Avoid longjmp/setjmp symbol clashes with libpthread.a
Building a statically linked UML kernel on a Centos 6.9 host resulted in
the following linking failure (GCC 4.4, glibc-2.12):

/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o):
In function `siglongjmp':
(.text+0x8490): multiple definition of `longjmp'
arch/x86/um/built-in.o:/local/users/fainelli/openwrt/trunk/build_dir/target-x86_64_musl/linux-uml/linux-4.4.69/arch/x86/um/setjmp_64.S:44:
first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o):
In function `sem_open':
(.text+0x77cd): warning: the use of `mktemp' is dangerous, better use
`mkstemp'
collect2: ld returned 1 exit status
make[4]: *** [vmlinux] Error 1

Adopt a solution similar to the one done for vmap where we define
longjmp/setjmp to be kernel_longjmp/setjmp. In the process, make sure we
do rename the functions in arch/x86/um/setjmp_*.S accordingly.

Fixes: a7df4716d1 ("um: link with -lpthread")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-07-05 23:30:50 +02:00
Arnd Bergmann
58ab5e0c2c Kbuild: arch: look for generated headers in obtree
There are very few files that need add an -I$(obj) gcc for the preprocessor
or the assembler. For C files, we add always these for both the objtree and
srctree, but for the other ones we require the Makefile to add them, and
Kbuild then adds it for both trees.

As a preparation for changing the meaning of the -I$(obj) directive to
only refer to the srctree, this changes the two instances in arch/x86 to use
an explictit $(objtree) prefix where needed, otherwise we won't find the
headers any more, as reported by the kbuild 0day builder.

arch/x86/realmode/rm/realmode.lds.S:75:20: fatal error: pasyms.h: No such file or directory

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-18 21:31:35 +02:00
Lorenzo Colitti
fb1770aa78 arch: um: fix error when linking vmlinux.
On gcc Ubuntu 4.8.4-2ubuntu1~14.04, linking vmlinux fails with:

arch/um/os-Linux/built-in.o: In function `os_timer_create':
/android/kernel/android/arch/um/os-Linux/time.c:51: undefined reference to `timer_create'
arch/um/os-Linux/built-in.o: In function `os_timer_set_interval':
/android/kernel/android/arch/um/os-Linux/time.c:84: undefined reference to `timer_settime'
arch/um/os-Linux/built-in.o: In function `os_timer_remain':
/android/kernel/android/arch/um/os-Linux/time.c:109: undefined reference to `timer_gettime'
arch/um/os-Linux/built-in.o: In function `os_timer_one_shot':
/android/kernel/android/arch/um/os-Linux/time.c:132: undefined reference to `timer_settime'
arch/um/os-Linux/built-in.o: In function `os_timer_disable':
/android/kernel/android/arch/um/os-Linux/time.c:145: undefined reference to `timer_settime'

This is because -lrt appears in the generated link commandline
after arch/um/os-Linux/built-in.o. Fix this by removing -lrt from
arch/um/Makefile and adding it to the UM-specific section of
scripts/link-vmlinux.sh.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-12-08 22:25:13 +01:00
Anton Ivanov
2eb5f31bc4 um: Switch clocksource to hrtimers
UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the cpu
load.

This patch fixes this by moving to posix high resolution
timers firing off CLOCK_MONOTONIC and relaying the timer
correctly to the UML userspace.

Fixes:
 - crashes when hosts suspends/resumes
 - broken userspace timers - effecive ~40Hz instead
   of what they should be. Note - this modifies skas behavior
   by no longer setting an itimer per clone(). Timer events
   are relayed instead.
 - kernel network packet scheduling disciplines
 - tcp behaviour especially under load
 - various timer related corner cases

Finally, overall responsiveness of userspace is better.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Anton Ivanov <aivanov@brocade.com>
[rw: massaged commit message]
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:54:49 +01:00
Richard Weinberger
0b5aedfe0e um: Fix out-of-tree build
Commit 30b11ee9a (um: Remove copy&paste code from init.h)
uncovered an issue wrt. out-of-tree builds.
For out-of-tree builds, we must not rely on relative paths.
Before 30b11ee9a it worked by chance as no host code included
generated header files.

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19 22:53:36 +02:00
Richard Weinberger
298e20ba8c um: Stop abusing __KERNEL__
Currently UML is abusing __KERNEL__ to distinguish between
kernel and host code (os-Linux). It is better to use a custom
define such that existing users of __KERNEL__ don't get confused.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 22:05:32 +02:00
Masahiro Yamada
a436bb7b80 kbuild: use relative path more to include Makefile
Prior to this commit, it was impossible to use relative path to
include Makefiles from the top level Makefile because the option
"--include-dir=$(srctree)" becomes effective when Make enters into
sub Makefiles.

To use relative path in any places, this commit moves the option
above the "sub-make" target.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-04-02 16:42:08 +02:00
Michal Marek
d4bc590f87 um: Fix for relative objtree when generating x86 headers
In an O= build, rely on the generated Makefile to call the main Makefile
properly. When building in the source tree, we do not need to specify
the -C and O= either. This fixes the problem when $(objtree) is a
relative path and the -C changes the directory.

Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-06-05 17:55:48 +02:00
Richard Weinberger
fff6540cbc um: Build always with -mcmodel=large on 64bit
On UML SUBARCH can be x86, x86_64 and i386 and if it is x86
we use uname -m to select a defconfig.
Therefore we can no longer use -mcmodel=large only if SUBARCH
is x86_64.

Reported-and-tested-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2013-12-01 13:06:51 +01:00
Ramkumar Ramachandra
e40f04d040 arch/um: make it work with defconfig and x86_64
arch/um/defconfig only lists one default configuration, and that applies
only to the i386 architecture.  Replace it with two minimal
configuration files generated using `make savedefconfig`:

  i386_defconfig and x86_64_defconfig

The build scripts now require two updates:

1. um's Kconfig (arch/x86/um/Kconfig) should specify an ARCH_DEFCONFIG
   section explicitly pointing to these scripts if the required
   variables are set.  Take care to remove the DEFCONFIG_LIST section
   defined in the included file arch/um/Kconfig.common.

2. um's Makefile (arch/um/Makefile) should set KBUILD_DEFCONFIG properly
   for the top-level Makefile to pick up.  Copy the logic in
   arch/x86/Makefile to properly pick the defconfig file depending on
   the actual architecture; except we're working with $SUBARCH here,
   instead of $ARCH.

Now, you can do:

  $ ARCH=um make defconfig
  $ ARCH=um make

and successfully build User-Mode Linux on an x86_64 box in default
configuration.

Cc: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2013-11-17 11:31:48 +01:00
David Howells
abbf1590de UAPI: Partition the header include path sets and add uapi/ header directories
Partition the header include path flags into two sets, one for kernelspace
builds and one for userspace builds.

Add the following directories to build after the ordinary include directories
so that #include will pick up the UAPI header directly if the kernel header
has been moved there.

The userspace set (represented by the USERINCLUDE make variable) contains:

	-I $(srctree)/arch/$(hdr-arch)/include/uapi
	-I arch/$(hdr-arch)/include/generated/uapi
	-I $(srctree)/include/uapi
	-I include/generated/uapi
	-include $(srctree)/include/linux/kconfig.h

and the kernelspace set (represented by the LINUXINCLUDE make variable)
contains:

	-I $(srctree)/arch/$(hdr-arch)/include
	-I arch/$(hdr-arch)/include/generated
	-I $(srctree)/include
	-I include		--- if not building in the source tree

plus everything in the USERINCLUDE set.

Then use USERINCLUDE in building the x86 boot code.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-02 18:01:26 +01:00
Sam Ravnborg
1f2bfbd00e kbuild: link of vmlinux moved to a script
Move the final link of vmlinux to a script to improve
readability and maintainability of the code.

The Makefile fragments used to link vmlinux has over the
years seen far too many changes and the logic had become
hard to follow.

As the process by nature is serialized there was
nothing gained including this in the Makefile.

"um" has special link requirments - and the
only way to handle this was to hard-code the linking
of "um" in the script.
This was better than trying to modularize it only for the
benefit of "um" anyway.

The shell script has been improved after input from:
Arnaud Lacombe <lacombar@gmail.com>
Nick Bowler <nbowler@elliptictech.com>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Arnaud Lacombe <lacombar@gmail.com>
Cc: Nick Bowler <nbowler@elliptictech.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-05-05 21:19:33 +02:00
Richard Weinberger
12783aa077 um: Switch to large mcmodel on x86_64
x86_64 UML is unable to load modules if more than 504MiB
of memory are used.
This happens because on x86_64 the UML process has a quite high
start address (typically around 0x6000000).
If UML's memory is larger than 504MiB VMALLOC_START happens to be after
0x8000000. This is no problem unless one loads a module which was built
with R_X86_64_32S relocations.
Symbols with a location > 0x8000000 cannot be used with R_X86_64_32S

To deal with this x86_64 UML has to be compiled with -mcmodel=large
such that no R_X86_64_32S relocations are used.

Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: 전하늘 <allskyee@gmail.com>
2012-03-25 00:29:57 +01:00
Al Viro
dc5be20a64 um: most of the SUBARCH uses can be killed
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[richard@nod.at: Re-export SUBARCH in arch/um/Makefile]
Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25 00:29:56 +01:00
H. Peter Anvin
79320bcbf0 um: Use $(srctree) not $(KBUILD_SRC)
$(KBUILD_SRC) is not defined without O=, use $(srctree).

Reported-and-tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2011-12-09 10:59:59 -08:00
H. Peter Anvin
392f4b7db8 um: Generate headers before generating user-offsets.s
In case we need generated header files for the values in
user-offsets.h, make sure we build generated header files before
user-offsets.s is built.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-12-05 16:06:02 -08:00
H. Peter Anvin
c9b284b202 um: Run host archheaders, allow use of host generated headers
Run the "archheaders" target for the host architecture, for
architectures (like x86, now) that want to generate some of the
necessary header files.

Add $(HOST_DIR)/include/generated to the include path so we then pick
them up.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-12-05 16:03:30 -08:00
Al Viro
5c48b108ec um: take arch/um/sys-x86 to arch/x86/um
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:05 +01:00
Al Viro
7bbe7204e9 um: merge Makefile-{i386,x86_64}
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:04 +01:00
Al Viro
6582b7f774 um: merge arch/um/sys-{i386,x86_64}
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:51 +01:00
Al Viro
858ba94499 um: merge arch/um/sys-{i386,x86_64}/shared
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:50 +01:00
Al Viro
27f85f1263 um: merge arch/um/sys-{i386,x86_64}/asm
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:50 +01:00
Al Viro
9e636452d0 um: get rid of kern_constants.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:45 +01:00