On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Standardize warning, error, and success printout format
of insn_decode_test so that user can easily understand
which test tool caused the messages.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/151153628279.22827.4869104298276788693.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rename distill.awk to objdump_reformat.awk because it more
clearly expresses its purpose of re-formatting the output
of objdump so that insn_decoder_test can read it.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/151153625409.22827.10470603625519700259.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rename test_get_len test command to insn_decoder_test
as it a more meaningful name. This also changes some
comments in related files.
Note that this also removes the paragraph about
writing to the Free Software Foundation's mailing
address.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/151153622537.22827.14928774603980883278.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gcc-7 warns:
In file included from arch/x86/tools/relocs_64.c:17:0:
arch/x86/tools/relocs.c: In function ‘process_64’:
arch/x86/tools/relocs.c:953:2: warning: argument 1 null where non-null expected [-Wnonnull]
qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from arch/x86/tools/relocs.h:6:0,
from arch/x86/tools/relocs_64.c:1:
/usr/include/stdlib.h:741:13: note: in a call to function ‘qsort’ declared here
extern void qsort
This happens because relocs16 is not used for ELF_BITS == 64,
so there is no point in trying to sort it.
Make the sort_relocs(&relocs16) call 32bit only.
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Link: http://lkml.kernel.org/r/20161215124513.GA289@x4
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull x86 asm updates from Ingo Molnar:
"The main changes in this development cycle were:
- a large number of call stack dumping/printing improvements: higher
robustness, better cross-context dumping, improved output, etc.
(Josh Poimboeuf)
- vDSO getcpu() performance improvement for future Intel CPUs with
the RDPID instruction (Andy Lutomirski)
- add two new Intel AVX512 features and the CPUID support
infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela,
He Chen)
- more copy-user unification (Borislav Petkov)
- entry code assembly macro simplifications (Alexander Kuleshov)
- vDSO C/R support improvements (Dmitry Safonov)
- misc fixes and cleanups (Borislav Petkov, Paul Bolle)"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
scripts/decode_stacktrace.sh: Fix address line detection on x86
x86/boot/64: Use defines for page size
x86/dumpstack: Make stack name tags more comprehensible
selftests/x86: Add test_vdso to test getcpu()
x86/vdso: Use RDPID in preference to LSL when available
x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
x86/cpufeatures: Enable new AVX512 cpu features
x86/cpuid: Provide get_scattered_cpuid_leaf()
x86/cpuid: Cleanup cpuid_regs definitions
x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
x86/unwind: Ensure stack grows down
x86/vdso: Set vDSO pointer only after success
x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE
x86/unwind: Detect bad stack return address
x86/dumpstack: Warn on stack recursion
x86/unwind: Warn on bad frame pointer
x86/decoder: Use stderr if insn sanity test fails
x86/decoder: Use stdout if insn decoder test is successful
mm/page_alloc: Remove kernel address exposure in free_reserved_area()
x86/dumpstack: Remove raw stack dump
...
Fixes below warning with clang:
In file included from ../arch/x86/tools/relocs_64.c:17:
../arch/x86/tools/relocs.c:977:6: warning: variable 'do_reloc' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161126222229.673-1-pefoley2@pefoley.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If the instruction sanity test fails, it prints a "Failure" message to
stdout. Make this program behave like the rest of the build and print
that message to stderr.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1477428965-20548-3-git-send-email-pebolle@tiscali.nl
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If the instruction decoder test ran successful it prints a message like
this to stderr:
Succeed: decoded and checked 1767380 instructions
But, as described in "console mode programming user interface guidelines
version 101" which doesn't exist, programs should use stderr for errors
or warnings. We're told about a successful run here, so the instruction
decoder test should use stdout.
Let's fix the typo too, while we're at it.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1477428965-20548-2-git-send-email-pebolle@tiscali.nl
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add support for Intel's AVX-512 instructions to the instruction decoder.
AVX-512 instructions are documented in Intel Architecture Instruction
Set Extensions Programming Reference (February 2016).
AVX-512 instructions are identified by a EVEX prefix which, for the
purpose of instruction decoding, can be treated as though it were a
4-byte VEX prefix.
Existing instructions which can now accept an EVEX prefix need not be
further annotated in the op code map (x86-opcode-map.txt). In the case
of new instructions, the op code map is updated accordingly.
Also add associated Mask Instructions that are used to manipulate mask
registers used in AVX-512 instructions.
The 'perf tools' instruction decoder is updated in a subsequent patch.
And a representative set of instructions is added to the perf tools new
instructions test in a subsequent patch.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since 'run_size' is now calculated in misc.c, the old script and associated
argument passing is no longer needed. This patch removes them, and renames
'run_size' to the more descriptive 'kernel_total_size'.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
[ Rewrote the changelog, renamed 'run_size' to 'kernel_total_size' ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Junjie Mao <eternal.n08@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1461888548-32439-6-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit e6023367d7 ("x86, kaslr: Prevent .bss from overlaping initrd")
added Perl to the required build environment. This reimplements in
shell the Perl script used to find the size of the kernel with bss and
brk added.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Rob Landley <rob@landley.net>
Acked-by: Rob Landley <rob@landley.net>
Cc: Anca Emanuel <anca.emanuel@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Junjie Mao <eternal.n08@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 boot and percpu updates from Ingo Molnar:
"This tree contains a bootable images documentation update plus three
slightly misplaced x86/asm percpu changes/optimizations"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86-64: Use RIP-relative addressing for most per-CPU accesses
x86-64: Handle PC-relative relocations on per-CPU data
x86: Convert a few more per-CPU items to read-mostly ones
x86, boot: Document intermediates more clearly
Pull x86 MPX support from Thomas Gleixner:
"This enables support for x86 MPX.
MPX is a new debug feature for bound checking in user space. It
requires kernel support to handle the bound tables and decode the
bound violating instruction in the trap handler"
* 'x86-mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
asm-generic: Remove asm-generic arch_bprm_mm_init()
mm: Make arch_unmap()/bprm_mm_init() available to all architectures
x86: Cleanly separate use of asm-generic/mm_hooks.h
x86 mpx: Change return type of get_reg_offset()
fs: Do not include mpx.h in exec.c
x86, mpx: Add documentation on Intel MPX
x86, mpx: Cleanup unused bound tables
x86, mpx: On-demand kernel allocation of bounds tables
x86, mpx: Decode MPX instruction to get bound violation information
x86, mpx: Add MPX-specific mmap interface
x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specific
x86, mpx: Add MPX to disabled features
ia64: Sync struct siginfo with general version
mips: Sync struct siginfo with general version
mpx: Extend siginfo structure to include bound violation information
x86, mpx: Rename cfg_reg_u and status_reg
x86: mpx: Give bndX registers actual names
x86: Remove arbitrary instruction size limit in instruction decoder
When building with the Gold linker, the .bss and .brk areas of vmlinux
are shown as consecutive instead of having the same file offset. Allow
for either state, as long as things add up correctly.
Fixes: e6023367d7 ("x86, kaslr: Prevent .bss from overlaping initrd")
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Junjie Mao <eternal.n08@gmail.com>
Link: http://lkml.kernel.org/r/20141118001604.GA25045@www.outflux.net
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The current x86 instruction decoder steps along through the
instruction stream but always ensures that it never steps farther
than the largest possible instruction size (MAX_INSN_SIZE).
The MPX code is now going to be doing some decoding of userspace
instructions. We copy those from userspace in to the kernel and
they're obviously completely untrusted coming from userspace. In
addition to the constraint that instructions can only be so long,
we also have to be aware of how long the buffer is that came in
from userspace. This _looks_ to be similar to what the perf and
kprobes is doing, but it's unclear to me whether they are
affected.
The whole reason we need this is that it is perfectly valid to be
executing an instruction within MAX_INSN_SIZE bytes of an
unreadable page. We should be able to gracefully handle short
reads in those cases.
This adds support to the decoder to record how long the buffer
being decoded is and to refuse to "validate" the instruction if
we would have gone over the end of the buffer to decode it.
The kprobes code probably needs to be looked at here a bit more
carefully. This patch still respects the MAX_INSN_SIZE limit
there but the kprobes code does look like it might be able to
be a bit more strict than it currently is.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: x86@kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20141114153957.E6B01535@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When choosing a random address, the current implementation does not take into
account the reversed space for .bss and .brk sections. Thus the relocated kernel
may overlap other components in memory. Here is an example of the overlap from a
x86_64 kernel in qemu (the ranges of physical addresses are presented):
Physical Address
0x0fe00000 --+--------------------+ <-- randomized base
/ | relocated kernel |
vmlinux.bin | (from vmlinux.bin) |
0x1336d000 (an ELF file) +--------------------+--
\ | | \
0x1376d870 --+--------------------+ |
| relocs table | |
0x13c1c2a8 +--------------------+ .bss and .brk
| | |
0x13ce6000 +--------------------+ |
| | /
0x13f77000 | initrd |--
| |
0x13fef374 +--------------------+
The initrd image will then be overwritten by the memset during early
initialization:
[ 1.655204] Unpacking initramfs...
[ 1.662831] Initramfs unpacking failed: junk in compressed archive
This patch prevents the above situation by requiring a larger space when looking
for a random kernel base, so that existing logic can effectively avoids the
overlap.
[kees: switched to perl to avoid hex translation pain in mawk vs gawk]
[kees: calculated overlap without relocs table]
Fixes: 82fa9637a2 ("x86, kaslr: Select random position from e820 maps")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Junjie Mao <eternal.n08@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1414762838-13067-1-git-send-email-eternal.n08@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
per_cpu_load_addr is only used for 64-bit relocations, but is
declared in both configurations of relocs.c - with different
types. This has undefined behaviour in general. GNU ld is
documented to use the larger size in this case, but other tools
may differ and some warn about this.
References: https://bugs.debian.org/748577
Reported-by: Michael Tautschnig <mt@debian.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: 748577@bugs.debian.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1411561812.3659.23.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When we build an already built kernel again, arch/x86/syscalls/Makefile
and arch/x86/tools/Makefile emits "Nothing to be done for ..."
messages.
Here is the command log:
$ make defconfig
[ snip ]
$ make
[ snip ]
$ make
make[1]: Nothing to be done for `all'. <-----
make[1]: Nothing to be done for `relocs'. <-----
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
Besides not emitting those, "all" and "relocs" should be added to PHONY as well.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Peter Foley <pefoley2@pefoley.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Link: http://lkml.kernel.org/r/1397093742-11144-1-git-send-email-yamada.m@jp.panasonic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch move the vsyscall_gtod_data handling out of vsyscall_64.c
into an additonal file vsyscall_gtod.c to make the functionality
available for x86 32 bit kernel.
It also adds a new vsyscall_32.c which setup the VVAR page.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Improve the debuggability of relocations output. When trying to compare
the output between different linkers, it's handy to be able to see the
section names in output.
Signed-off-by: Michael Davidson <md@google.com>
Link: http://lkml.kernel.org/r/20140121203223.GA12649@www.outflux.net
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The GNU linker tries to put __per_cpu_load into the percpu area,
resulting in a lack of its relocation. Force this symbol to be
relocated. Seen starting with GNU ld 2.23 and later.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michael Davidson <md@google.com>
Cc: Cong Ding <dinggnu@gmail.com>
Link: http://lkml.kernel.org/r/20131016064314.GA2739@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "gold" linker doesn't seem to put some additional per-cpu cases in
the right place. Add these to the per-cpu check. Without this, the kASLR
patch series fails to correctly apply relocations, and fails to boot.
Signed-off-by: Michael Davidson <md@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20131011013954.GA28902@www.outflux.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86/asm changes from Ingo Molnar:
"Main changes:
- Apply low level mutex optimization on x86-64, by Wedson Almeida
Filho.
- Change bitops to be naturally 'long', by H Peter Anvin.
- Add TSX-NI opcodes support to the x86 (instrumentation) decoder, by
Masami Hiramatsu.
- Add clang compatibility adjustments/workarounds, by Jan-Simon
Möller"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, doc: Update uaccess.h comment to reflect clang changes
x86, asm: Fix a compilation issue with clang
x86, asm: Extend definitions of _ASM_* with a raw format
x86, insn: Add new opcodes as of June, 2013
x86/ia32/asm: Remove unused argument in macro
x86, bitops: Change bitops to be native operand size
x86: Use asm-goto to implement mutex fast path on x86-64
Add TSX-NI related instructions and new instructions to
x86-opcode-map.txt according to the Intel(R) 64 and IA-32
Architectures Software Developer's Manual Vol2C (June, 2013).
This also includes below updates.
- Fix a typo of MWAIT (the lack of (11B)).
- Change NOP Ev to prefetchw Ev
- Add CRC32 new prefix style (66&F2)
- Add ADCX, ADOX, RDSEED, CLAC and STAC instructions
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20130806073750.4049.12365.stgit@udc4-manage.rcp.hitachi.co.jp
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The __vvar_page relocation should actually be listed in S_REL instead
of S_ABS. Oddly, this didn't always cause things to break, presumably
because there are no users for relocation information on 64 bits yet.
[ hpa: Not for stable - new code in 3.10 ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130611185652.GA23674@www.outflux.net
Reported-by: Michael Davidson <md@google.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Since the ELF structures and access macros change size based on 32 vs
64 bits, build a separate 32-bit relocs tool (for handling realmode
and 32-bit relocations), and a 64-bit relocs tool (for handling 64-bit
kernel relocations).
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-5-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This adds the ability to process relocations from the 64-bit kernel ELF,
if built with ELF_BITS=64 defined. The special case for the percpu area is
handled, along with some other symbols specific to the 64-bit kernel.
Based on work by Neill Clift and Michael Davidson.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-4-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Instead of counting and then processing relocations, do it in a single
pass. This splits the processing logic into separate functions for
realmode and 32-bit (and paves the way for 64-bit). Also extracts helper
functions when emitting relocations.
Based on work by Neill Clift and Michael Davidson.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-3-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
In preparation for making the reloc tool operate on 64-bit relocations,
generalize the structure names for easy recompilation via #defines.
Based on work by Neill Clift and Michael Davidson.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-2-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull perf fixes from Ingo Molnar:
"Three fixlets and two small (and low risk) hw-enablement changes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix event group context move
x86/perf: Add IvyBridge EP support
perf/x86: Fix P6 driver section warning
arch/x86/tools/insn_sanity.c: Identify source of messages
perf/x86: Enable Intel Lincroft/Penwell/Cloverview Atom support
The kernel build prints:
Building modules, stage 2.
TEST posttest
MODPOST 3821 modules
TEST posttest
Success: decoded and checked 1000000 random instructions with 0
errors (seed:0xaac4bc47) CC arch/x86/boot/a20.o
CC arch/x86/boot/cmdline.o
AS arch/x86/boot/copy.o
HOSTCC arch/x86/boot/mkcpustr
CC arch/x86/boot/cpucheck.o
CC arch/x86/boot/early_serial_console.o
which is irritating because you don't know what program is
proudly pronouncing its success.
So, as described in "console mode programming user interface
guidelines version 101" which doesn't exist, change this program
to identify the source of its messages.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The original version code causes following sparse warnings:
arch/x86/lib/inat-tables.c:1080:25: warning: duplicate const
arch/x86/lib/inat-tables.c:1095:25: warning: duplicate const
arch/x86/lib/inat-tables.c:1118:25: warning: duplicate const
for the variables inat_escape_tables, inat_group_tables, and inat_avx_tables
in the code generated by gen-insn-attr-x86.awk.
The author Masami Hiramutsu says here is to make both the value pointed by the
pointers and the pointers itself read-only, so we move the "const" to be after
the "*".
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Link: http://lkml.kernel.org/r/20121209082103.GA9181@gmail.com
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Fix the x86 test_get_len tool to have the right include paths in the right
order (it includes a non-exported kernel header directly), otherwise errors
like the following occur:
/data/fs/linux-2.6-hdr/include/linux/types.h:18:26: error: conflicting types for 'fd_set'
/usr/include/sys/select.h:78:5: note: previous declaration of 'fd_set' was here
and
/data/fs/linux-2.6-hdr/include/linux/string.h:42:12: error: expected identifier or '(' before '__extension__'
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>
Fix the x86 instruction decoder to decode bsr/bsf/jmpe with
operand-size prefix (66h). This fixes the test case failure
reported by Linus, attached below.
bsf/bsr/jmpe have a special encoding. Opcode map in
Intel Software Developers Manual vol2 says they have
TZCNT/LZCNT variants if it has F3h prefix. However, there
is no information if it has other 66h or F2h prefixes.
Current instruction decoder supposes that those are
bad instructions, but it actually accepts at least
operand-size prefixes.
H. Peter Anvin further explains:
" TZCNT/LZCNT are F3 + BSF/BSR exactly because the F2 and
F3 prefixes have historically been no-ops with most instructions.
This allows software to unconditionally use the prefixed versions
and get TZCNT/LZCNT on the processors that have them if they don't
care about the difference. "
This fixes errors reported by test_get_len:
Warning: arch/x86/tools/test_get_len found difference at <em_bsf>:ffffffff81036d87
Warning: ffffffff81036de5: 66 0f bc c2 bsf %dx,%ax
Warning: objdump says 4 bytes, but insn_get_length() says 3
Warning: arch/x86/tools/test_get_len found difference at <em_bsr>:ffffffff81036ea6
Warning: ffffffff81036f04: 66 0f bd c2 bsr %dx,%ax
Warning: objdump says 4 bytes, but insn_get_length() says 3
Warning: decoded and checked 13298882 instructions with 2 warnings
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <yrl.pp-manager.tt@hitachi.com>
Link: http://lkml.kernel.org/r/20120604150911.22338.43296.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 trampoline rework from H. Peter Anvin:
"This code reworks all the "trampoline"/"realmode" code (various bits
that need to live in the first megabyte of memory, most but not all of
which runs in real mode at some point) in the kernel into a single
object. The main reason for doing this is that it eliminates the last
place in the kernel where we needed pages to be mapped RWX. This code
separates all that code into proper R/RW/RX pages."
Fix up conflicts in arch/x86/kernel/Makefile (mca removed next to reboot
code), and arch/x86/kernel/reboot.c (reboot code moved around in one
branch, modified in this one), and arch/x86/tools/relocs.c (mostly same
code came in earlier due to working around the ld bugs just before the
3.4 release).
Also remove stale x86-relocs entry from scripts/.gitignore as per Peter
Anvin.
* commit '61f5446169046c217a5479517edac3a890c3bee7': (36 commits)
x86, realmode: Move end signature into header.S
x86, relocs: When printing an error, say relative or absolute
x86, relocs: More relocations which may end up as absolute
x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
xen-acpi-processor: Add missing #include <xen/xen.h>
acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c
x86, realmode: Change EFER to a single u64 field
x86, realmode: Move kernel/realmode.c to realmode/init.c
x86, realmode: Move not-common bits out of trampoline_common.S
x86, realmode: Mask out EFER.LMA when saving trampoline EFER
x86, realmode: Fix no cache bits test in reboot_32.S
x86, realmode: Make sure all generated files are listed in targets
x86, realmode: build fix: remove duplicate build
x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
x86, realmode: fixes compilation issue in tboot.c
x86, realmode: move relocs from scripts/ to arch/x86/tools
x86, realmode: header for trampoline code
x86, realmode: flattened rm hierachy
x86, realmode: don't copy real_mode_header
x86, realmode: fix 64-bit wakeup sequence
...
The symbol jiffies is created in the linker script as an alias to
jiffies_64. Unfortunately this is done outside any section, and
apparently GNU ld 2.21 doesn't carry the section with it, so we end up
with an absolute symbol and therefore a broken kernel.
Add jiffies and jiffies_64 to the whitelist.
The most disturbing bit with this discovery is that it shows that we
have had multiple linker bugs in this area crossing multiple
generations, and have been silently building bad kernels for some time.
Link: http://lkml.kernel.org/r/20120524171604.0d98284f3affc643e9714470@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org> v3.4
As noted in checkin:
a3e854d95 x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
ld version 2.22.52.0.[12] can incorrectly promote relative symbols to
absolute, if the output section they appear in is otherwise empty.
Since checkin:
6520fe55 x86, realmode: 16-bit real-mode code support for relocs tool
we actually check for this and error out rather than silently creating
a kernel which will malfunction if relocated.
Ingo found a configuration in which __start_builtin_fw triggered the
warning.
Go through the linker script sources and look for more symbols that
could plausibly get bogusly promoted to absolute, and add them to the
whitelist.
In general, if the following error triggers:
Invalid absolute R_386_32 relocation: <symbol>
... then we should verify that <symbol> is really meant to be
relocated, and add it and any related symbols manually to the S_REL
regexp.
Please note that 6520fe55 does not introduce the error, only the check
for the error -- without 6520fe55 this version of ld will simply
produce a corrupt kernel if CONFIG_RELOCATABLE is set on x86-32.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org> v3.4
When the relocs tool throws an error, let the error message say if it
is an absolute or relative symbol. This should make it a lot more
clear what action the programmer needs to take and should help us find
the reason if additional symbol bugs show up.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
A new option is added to the relocs tool called '--realmode'.
This option causes the generation of 16-bit segment relocations
and 32-bit linear relocations for the real-mode code. When
the real-mode code is moved to the low-memory during kernel
initialization, these relocation entries can be used to
relocate the code properly.
In the assembly code 16-bit segment relocations must be relative
to the 'real_mode_seg' absolute symbol. Linear relocations must be
relative to a symbol prefixed with 'pa_'.
16-bit segment relocation is used to load cs:ip in 16-bit code.
Linear relocations are used in the 32-bit code for relocatable
data references. They are declared in the linker script of the
real-mode code.
The relocs tool is moved to arch/x86/tools/relocs.c, and added new
target archscripts that can be used to build scripts needed building
an architecture. be compiled before building the arch/x86 tree.
[ hpa: accelerating this because it detects invalid absolute
relocations, a serious bug in binutils 2.22.52.0.x which currently
produces bad kernels. ]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
When the relocs tool throws an error, let the error message say if it
is an absolute or relative symbol. This should make it a lot more
clear what action the programmer needs to take.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
This bug is exposed by checkin
433de739bb x86, realmode: 16-bit real-mode code support for relocs tool
only in the sense that that checkin changes the relocs tool to report
an error instead of silently generating a kernel which is broken if
relocated.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Moved relocs tool from scripts/ to arch/x86/tools because
it is architecture specific script. Added new target archscripts
that can be used to build scripts needed building an architecture.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-22-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
