Commit Graph

1038 Commits

Author SHA1 Message Date
Josh Poimboeuf
d5b0f02528 objtool/klp: Fix pointer comparisons for rodata objects
klp-diff treats all rodata as uncorrelated, so any reference to it uses
a duplicated copy rather than using a KLP reloc.

For the contents of the data itself, a duplicated copy is fine.
However, pointer comparisons (e.g., f->f_op == &foo_ops) are broken.

Fix it by correlating non-anonymous rodata objects.

Also, use a new find_symbol_containing_inclusive() helper for matching
the end of a symbol so bounds calculations don't get broken, for the
case where an array or other symbol's ending address is used as part of
a bounds calculation.

While these are really two distinct changes, they need to be done in the
same patch so as to avoid introducing bisection regressions.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:02 -07:00
Josh Poimboeuf
8fdc3585b3 objtool/klp: Simplify reloc symbol conversion
Inline section_reference_needed() and is_reloc_allowed() into
convert_reloc_sym() and remove the redundant is_reloc_allowed() check in
clone_reloc().

Move the is_sec_sym() checks into the convert callees so they become
no-ops when the reloc is already in the right format.  This allows
convert_reloc_sym() to unconditionally dispatch to the right converter
based on section type.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:01 -07:00
Josh Poimboeuf
3e01ab44af objtool: Move mark_rodata() to elf.c
Move the sec->rodata marking from check.c to elf.c so it's set during
ELF reading rather than during the check pipeline.  This makes the
rodata flag available to all objtool users, including klp-diff which
reads ELF files directly without running check().

Add an is_rodata_sec() helper to elf.h for consistency with
is_text_sec() and is_string_sec().

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:01 -07:00
Josh Poimboeuf
3787e82a4e objtool/klp: Fix relocation conversion failures for R_X86_64_NONE
Objtool has some hacks which NOP out certain calls/jumps and replace
their relocations with R_X86_64_NONE.  The klp-diff relocation
extraction code will error out when trying to copy these relocations due
to their negative addend, which would only makes sense for a PC-relative
branch instruction.  Just ignore them.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:01 -07:00
Josh Poimboeuf
da4326573a objtool/klp: Fix kCFI trap handling
.kcfi_traps contains references to kCFI trap instruction locations.
When a KCFI type check fails at an indirect call, the trap handler looks
up the faulting address in this section.

Add it to the special sections list so the entries get extracted for the
changed functions they reference.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:01 -07:00
Josh Poimboeuf
62a7a01fde objtool/klp: Fix extraction of text annotations for alternatives
Objtool is failing to extract text annotations which reference
.altinstr_replacement instructions:

  1) Alternative replacement fake symbols are NOTYPE rather than FUNC,
     and they don't have sym->included set, thus they aren't recognized
     by should_keep_special_sym().

  2) .discard.annotate_insn gets processed before .altinstr_replacement,
     so the referenced (fake) symbols don't have clones yet.

Fix the first issue by checking for a valid clone instead of
sym->included and by accepting NOTYPE symbols when processing
.discard.annotate_insn.

Fix the second issue by deferring text annotation processing until after
the other special sections have been cloned.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:01 -07:00
Josh Poimboeuf
479ac5260e objtool/klp: Fix XXH3 state memory leak
The XXH3 state allocated in checksum_init() is never freed.  Free it in
checksum_finish().

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:01 -07:00
Josh Poimboeuf
98377f3ba7 objtool/klp: Fix cloning of zero-length section symbols
Fix NULL dereference when cloning a symbol from an empty section.
sec->data is only populated for sections with non-zero size.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Josh Poimboeuf
c4c02d4450 objtool/klp: Fix handling of zero-length .altinstr_replacement sections
When a section is empty (e.g. only zero-length alternative
replacements), there are no symbols to convert a section symbol
reference to.  Skip the reloc instead of erroring out.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Josh Poimboeuf
def5b60dcd objtool/klp: Fix --debug-checksum for duplicate symbol names
find_symbol_by_name() only returns the first match, so
--debug-checksum=<func> silently ignores any subsequent duplicately
named functions after the first.

Fix that, along with a new for_each_sym_by_name() helper.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Josh Poimboeuf
0333b73995 objtool: Replace iterator callback with for_each_sym_by_mangled_name()
Convert the callback-based iterate_sym_by_demangled_name() with a new
for_each_sym_by_demangled_name() macro.  This eliminates the callback
struct/function and makes the code more compact and readable.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Joe Lawrence
3de711fba7 objtool/klp: Fix create_fake_symbols() skipping entsize-based sections
create_fake_symbols() has two phases: creating symbols from
ANNOTATE_DATA_SPECIAL entries, and a fallback that uses sh_entsize for
special sections like .static_call_sites.

When .discard.annotate_data is absent, the function returns early,
skipping the entsize fallback and silently allowing unsupported
module-local static call keys through.

Fix it by jumping to the entsize phase instead of returning early.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Assisted-by: Claude:claude-4-opus
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Josh Poimboeuf
e872b3f139 objtool/klp: Improve local label check
Clang emits various .L-prefixed local symbols beyond .Ltmp*, such as
.L__const.* for local constant data.  These are assembler-local labels
not present in kallsyms, so they can never be resolved at module load
time.

Broaden the check from .Ltmp* to all .L* symbols so they get cloned into
the patch module instead.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Josh Poimboeuf
76eb0f8639 objtool/klp: Don't report uncorrelated functions as new
Clang LTO uses __UNIQUE_ID() to generate some uniquely named wrapper
functions, like initstubs.  If they're uncorrelated, prevent them from
being reported as new functions and included unnecessarily.

Note that dont_correlate() already includes prefix functions, so prefix
functions are still being ignored here.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:00 -07:00
Josh Poimboeuf
0a7823d1d7 objtool/klp: Don't correlate __initstub__ symbols
With LTO, the initcall infrastructure generates __initstub__kmod_*
wrapper functions in .init.text.  These are the LTO equivalent of
__initcall__kmod_* data pointers, which are already excluded from
correlation.

These are __init functions whose memory is freed after boot, so there's
no reason to include or reference them in a livepatch module.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:15:59 -07:00
Josh Poimboeuf
710c4c2546 objtool/klp: Don't correlate absolute symbols
Some arch/x86/crypto/*.S files define local .set/.equ constants that get
duplicated in vmlinux.o.  This causes klp-diff to fail with "Multiple
correlation candidates" errors since it can't uniquely match these
between orig and patched builds.

Skip ABS symbols in dont_correlate().  They're purely compile-time
assembly constants that are never referenced by relocations, so they
don't need correlation.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:15:59 -07:00
Josh Poimboeuf
8edec01625 objtool/klp: Don't correlate __ADDRESSABLE() symbols
Symbols created by __ADDRESSABLE() are only used to convince the
toolchain not to optimize out the referenced symbol.

Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:15:59 -07:00
Josh Poimboeuf
ff529864e7 objtool/klp: Fix .data..once static local non-correlation
While there was once a section named .data.once, it has since been
renamed to .data..once with commit dbefa1f31a ("Rename .data.once to
.data..once to fix resetting WARN*_ONCE").  Fix it.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:15:59 -07:00
Joe Lawrence
84c304a534 objtool/klp: Fix is_uncorrelated_static_local() for Clang
For naming function-local static locals, GCC uses <var>.<id>, e.g.
__already_done.15, while Clang uses <func>.<var> with optional .<id>,
e.g. create_worker.__already_done.111

The existing is_uncorrelated_static_local() check only matches the GCC
convention where the variable name is a prefix.  Handle both cases by
checking for a prefix match (GCC) and by checking after the first dot
separator (Clang).

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:15:59 -07:00
Linus Torvalds
4b2bdc2221 objtool updates for v7.1:
- KLP support updates and fixes (Song Liu)
 
  - KLP-build script updates and fixes (Joe Lawrence)
 
  - Support Clang RAX DRAP sequence, to address clang
    false positive (Josh Poimboeuf)
 
  - Reorder ORC register numbering to match regular x86
    register numbering (Josh Poimboeuf)
 
  - Misc cleanups (Wentong Tian, Song Liu)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - KLP support updates and fixes (Song Liu)

 - KLP-build script updates and fixes (Joe Lawrence)

 - Support Clang RAX DRAP sequence, to address clang false positive
   (Josh Poimboeuf)

 - Reorder ORC register numbering to match regular x86 register
   numbering (Josh Poimboeuf)

 - Misc cleanups (Wentong Tian, Song Liu)

* tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool/x86: Reorder ORC register numbering
  objtool: Support Clang RAX DRAP sequence
  livepatch/klp-build: report patch validation fuzz
  livepatch/klp-build: add terminal color output
  livepatch/klp-build: provide friendlier error messages
  livepatch/klp-build: improve short-circuit validation
  livepatch/klp-build: fix shellcheck complaints
  livepatch/klp-build: add Makefile with check target
  livepatch/klp-build: add grep-override function
  livepatch/klp-build: switch to GNU patch and recountdiff
  livepatch/klp-build: support patches that add/remove files
  objtool/klp: Correlate locals to globals
  objtool/klp: Match symbols based on demangled_name for global variables
  objtool/klp: Remove .llvm suffix in demangle_name()
  objtool/klp: Also demangle global objects
  objtool/klp: Use sym->demangled_name for symbol_name hash
  objtool/klp: Remove trailing '_' in demangle_name()
  objtool/klp: Remove redundant strcmp() in correlate_symbols()
  objtool: Use section/symbol type helpers
2026-04-14 13:00:04 -07:00
Linus Torvalds
fdcbb1bc06 Merge branch 'nocache-cleanup'
This series cleans up some of the special user copy functions naming and
semantics.  In particular, get rid of the (very traditional) double
underscore names and behavior: the whole "optimize away the range check"
model has been largely excised from the other user accessors because
it's so subtle and can be unsafe, but also because it's just not a
relevant optimization any more.

To do that, a couple of drivers that misused the "user" copies as kernel
copies in order to get non-temporal stores had to be fixed up, but that
kind of code should never have been allowed anyway.

The x86-only "nocache" version was also renamed to more accurately
reflect what it actually does.

This was all done because I looked at this code due to a report by Jann
Horn, and I just couldn't stand the inconsistent naming, the horrible
semantics, and the random misuse of these functions.  This code should
probably be cleaned up further, but it's at least slightly closer to
normal semantics.

I had a more intrusive series that went even further in trying to
normalize the semantics, but that ended up hitting so many other
inconsistencies between different architectures in this area (eg
'size_t' vs 'unsigned long' vs 'int' as size arguments, and various
iovec check differences that Vasily Gorbik pointed out) that I ended up
with this more limited version that fixed the worst of the issues.

Reported-by: Jann Horn <jannh@google.com>
Tested-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/CAHk-=wgg1QVWNWG-UCFo1hx0zqrPnB3qhPzUTrWNft+MtXQXig@mail.gmail.com/

* nocache-cleanup:
  x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcache
  x86: rename and clean up __copy_from_user_inatomic_nocache()
  x86-64: rename misleadingly named '__copy_user_nocache()' function
2026-04-13 08:39:51 -07:00
Linus Torvalds
d187a86de7 x86-64: rename misleadingly named '__copy_user_nocache()' function
This function was a masterclass in bad naming, for various historical
reasons.

It claimed to be a non-cached user copy.  It is literally _neither_ of
those things.  It's a specialty memory copy routine that uses
non-temporal stores for the destination (but not the source), and that
does exception handling for both source and destination accesses.

Also note that while it works for unaligned targets, any unaligned parts
(whether at beginning or end) will not use non-temporal stores, since
only words and quadwords can be non-temporal on x86.

The exception handling means that it _can_ be used for user space
accesses, but not on its own - it needs all the normal "start user space
access" logic around it.

But typically the user space access would be the source, not the
non-temporal destination.  That was the original intention of this,
where the destination was some fragile persistent memory target that
needed non-temporal stores in order to catch machine check exceptions
synchronously and deal with them gracefully.

Thus that non-descriptive name: one use case was to copy from user space
into a non-cached kernel buffer.  However, the existing users are a mix
of that intended use-case, and a couple of random drivers that just did
this as a performance tweak.

Some of those random drivers then actively misused the user copying
version (with STAC/CLAC and all) to do kernel copies without ever even
caring about the exception handling, _just_ for the non-temporal
destination.

Rename it as a first small step to actually make it halfway sane, and
change the prototype to be more normal: it doesn't take a user pointer
unless the caller has done the proper conversion, and the argument size
is the full size_t (it still won't actually copy more than 4GB in one
go, but there's also no reason to silently truncate the size argument in
the caller).

Finally, use this now sanely named function in the NTB code, which
mis-used a user copy version (with STAC/CLAC and all) of this interface
despite it not actually being a user copy at all.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-03-30 15:05:56 -07:00
Josh Poimboeuf
1735858caa objtool/x86: Reorder ORC register numbering
Reorder the ORC register values so their ordering matches the x86
instruction set register encodings.

No functional change intended.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2026-03-18 09:38:52 +01:00
Josh Poimboeuf
96f3b16a9d objtool: Support Clang RAX DRAP sequence
Recent Clang can use RAX as a temporary register for the DRAP stack
alignment sequence.  Add support for that.

Fixes the following warning:

  vmlinux.o: error: objtool: vmw_host_printf+0xd: unknown CFA base reg 0

Closes: https://lore.kernel.org/cefefdd1-7b82-406d-8ff4-e4b167e45ee6@app.fastmail.com
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/3f33dc720b83dc6d3a2b7094f75a5c90a0b1cbc5.1773708458.git.jpoimboe@kernel.org
2026-03-18 09:38:52 +01:00
Josh Poimboeuf
4e50192164 objtool: Fix Clang jump table detection
With Clang, there can be a conditional forward jump between the load of
the jump table address and the indirect branch.

Fixes the following warning:

  vmlinux.o: warning: objtool: ___bpf_prog_run+0x1c5: sibling call from callable instruction with modified stack frame

Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/a426d669-58bb-4be1-9eaa-6f3d83109e2d@app.fastmail.com
Link: https://patch.msgid.link/7d8600caed08901b6679767488acd639f6df9688.1773071992.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-16 15:31:25 -07:00
Joe Lawrence
28e367a969 objtool/klp: fix mkstemp() failure with long paths
The elf_create_file() function fails with EINVAL when the build directory
path is long enough to truncate the "XXXXXX" suffix in the 256-byte
tmp_name buffer.

Simplify the code to remove the unnecessary dirname()/basename() split
and concatenation.  Instead, allocate the exact number of bytes needed for
the path.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-3-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-16 12:40:31 -07:00
Joe Lawrence
2f2600decb objtool/klp: fix data alignment in __clone_symbol()
Commit 356e4b2f5b ("objtool: Fix data alignment in elf_add_data()")
corrected the alignment of data within a section (honoring the section's
sh_addralign).  Apply the same alignment when klp-diff mode clones a
symbol, adjusting the new symbol's offset for the output section's
sh_addralign.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-2-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-16 12:39:45 -07:00
Linus Torvalds
9745031130 Miscellaneous objtool fixes:
- Fix cross-build bug by using HOSTCFLAGS for HAVE_XXHASH test
  - Fix klp bug by fixing detection of corrupt static branch/call entries
  - Handle unsupported pr_debug() usage more gracefully
  - Fix hypothethical klp bug by avoiding NULL pointer dereference when printing code symbol name
  - Fix data alignment bug in elf_add_data() causing mangled strings
  - Fix confusing ERROR_INSN() error message
  - Handle unexpected Clang RSP musical chairs causing false positive warnings
  - Fix another objtool stack overflow in validate_branch()
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-urgent-2026-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar:

 - Fix cross-build bug by using HOSTCFLAGS for HAVE_XXHASH test

 - Fix klp bug by fixing detection of corrupt static branch/call entries

 - Handle unsupported pr_debug() usage more gracefully

 - Fix hypothetical klp bug by avoiding NULL pointer dereference when
   printing code symbol name

 - Fix data alignment bug in elf_add_data() causing mangled strings

 - Fix confusing ERROR_INSN() error message

 - Handle unexpected Clang RSP musical chairs causing false positive
   warnings

 - Fix another objtool stack overflow in validate_branch()

* tag 'objtool-urgent-2026-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix another stack overflow in validate_branch()
  objtool: Handle Clang RSP musical chairs
  objtool: Fix ERROR_INSN() error message
  objtool: Fix data alignment in elf_add_data()
  objtool: Use HOSTCFLAGS for HAVE_XXHASH test
  objtool/klp: Avoid NULL pointer dereference when printing code symbol name
  objtool/klp: Disable unsupported pr_debug() usage
  objtool/klp: Fix detection of corrupt static branch/call entries
2026-03-15 10:36:01 -07:00
Josh Poimboeuf
9a73f085dc objtool: Fix another stack overflow in validate_branch()
The insn state is getting saved on the stack twice for each recursive
iteration.  No need for that, once is enough.

Fixes the following reported stack overflow:

  drivers/scsi/qla2xxx/qla_dbg.o: error: SIGSEGV: objtool stack overflow!
  Segmentation fault

Fixes: 70589843b3 ("objtool: Add option to trace function validation")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/90956545-2066-46e3-b547-10c884582eb0@app.fastmail.com
Link: https://patch.msgid.link/8b97f62d083457f3b0a29a424275f7957dd3372f.1772821683.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-09 08:45:13 -07:00
Josh Poimboeuf
7fdaa640c8 objtool: Handle Clang RSP musical chairs
For no apparent reason (possibly related to CONFIG_KMSAN), Clang can
randomly pass the value of RSP to other registers and then back again to
RSP.  Handle that accordingly.

Fixes the following warnings:

  drivers/input/misc/uinput.o: warning: objtool: uinput_str_to_user+0x165: undefined stack state
  drivers/input/misc/uinput.o: warning: objtool: uinput_str_to_user+0x165: unknown CFA base reg -1

Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/90956545-2066-46e3-b547-10c884582eb0@app.fastmail.com
Link: https://patch.msgid.link/240e6a172cc73292499334a3724d02ccb3247fc7.1772818491.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-09 08:45:10 -07:00
Song Liu
4b57e97be2 objtool/klp: Correlate locals to globals
Allow correlating original locals to patched globals, and vice versa.
This is needed when:

1. User adds/removes "static" for a function.
2. CONFIG_LTO_CLANG_THIN promotes local functions and objects to global
   and add .llvm.<hash> suffix.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-8-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:34 -08:00
Song Liu
cdea5cadb0 objtool/klp: Match symbols based on demangled_name for global variables
correlate_symbols() will always try to match full name first. If there is
no match, try match only demangled_name.

In very rare cases, it is possible to have multiple foo.llvm.<hash> in
the same kernel. Whenever there is ambiguity like this, fail the klp diff.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-7-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:33 -08:00
Song Liu
020b71dcaf objtool/klp: Remove .llvm suffix in demangle_name()
Remove .llvm suffix, so that we can correlate foo.llvm.<hash 1> and
foo.llvm.<hash 2>.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-6-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:33 -08:00
Song Liu
8206277746 objtool/klp: Also demangle global objects
With CONFIG_LTO_CLANG_THIN, it is possible to have global __UNIQUE_ID,
such as:

   FUNC    GLOBAL HIDDEN  19745 __UNIQUE_ID_quirk_amd_nb_node_458

Also demangle global objects.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-5-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:32 -08:00
Song Liu
0b8fc6adc3 objtool/klp: Use sym->demangled_name for symbol_name hash
For klp-build with LTO, it is necessary to correlate demangled symbols,
e.g., correlate foo.llvm.<num 1> and foo.llvm.<num 2>. However, these two
symbols do not have the same str_hash(name). To be able to correlate the
two symbols, calculate hash based on demanged_name, so that these two
symbols have the same hash.

No functional changes intended.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-4-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:32 -08:00
Song Liu
a3f28d2072 objtool/klp: Remove trailing '_' in demangle_name()
With CONFIG_LTO_CLANG_THIN, it is possible to have nested __UNIQUE_ID_,
such as:

  __UNIQUE_ID_addressable___UNIQUE_ID_pci_invalid_bar_694_695

To remove both trailing numbers, also remove trailing '_'.

Also add comments to demangle_name().

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-3-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:30 -08:00
Song Liu
a1cbaff2ea objtool/klp: Remove redundant strcmp() in correlate_symbols()
find_global_symbol_by_name() already compares names of the two symbols,
so there is no need to compare them again.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260305231531.3847295-2-song@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:23 -08:00
Wentong Tian
c19c854b30 objtool: Use section/symbol type helpers
Commit 25eac74b6b ("objtool: Add section/symbol type helpers")
introduced several helper macros to improve code readability.

Update the remaining open-coded checks in check.c, disas.c, elf.c,
and klp-diff.c to use these new helpers.

Signed-off-by: Wentong Tian <tianwentong2000@gmail.com>
Link: https://patch.msgid.link/20260122144404.40602-1-tianwentong2000@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 08:08:19 -08:00
Josh Poimboeuf
1fd1dc4172 objtool: Fix ERROR_INSN() error message
Confusingly, ERROR_INSN() shows "warning:" instead of "error:".  Fix that.

Link: https://patch.msgid.link/c4fe793bb3d23fac2c636b2511059af1158410e2.1772681234.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 07:53:37 -08:00
Josh Poimboeuf
356e4b2f5b objtool: Fix data alignment in elf_add_data()
Any data added to a section needs to be aligned in accordance with the
section's sh_addralign value.  Particularly strings added to a .str1.8
section.  Otherwise you may get some funky strings.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Link: https://patch.msgid.link/d962fc0ca24fa0825cca8dad71932dccdd9312a9.1772681234.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 07:53:36 -08:00
HONG Yifan
3223404910 objtool: Use HOSTCFLAGS for HAVE_XXHASH test
Previously, HAVE_XXHASH is tested by invoking HOSTCC without HOSTCFLAGS.

Consider the following scenario:

- The host machine has libxxhash installed
- We build the kernel with HOSTCFLAGS containing a --sysroot that does
  not have xxhash.h (for hermetic builds)

In this case, HAVE_XXHASH is set to y, but when it builds objtool with
HOSTCFLAGS, because the --sysroot does not contain xxhash.h, the
following error is raised:

<...>/common/tools/objtool/include/objtool/checksum_types.h:12:10: fatal error: 'xxhash.h' file not found
   12 | #include <xxhash.h>
      |          ^~~~~~~~~~

To resolve the error, we test HAVE_XXHASH by invoking HOSTCC with
HOSTCFLAGS.

Signed-off-by: HONG Yifan <elsk@google.com>
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Link: https://patch.msgid.link/20260303010340.306164-1-elsk@google.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 07:48:41 -08:00
Josh Poimboeuf
11c2adcd1f objtool/klp: Avoid NULL pointer dereference when printing code symbol name
Fix a hypothetical NULL pointer defereference of the 'code_sym'
variable.  In theory this should never happen.

Reviewed-and-tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/64116517bc93851a98fe366ea0a4d807f4c70aab.1770759954.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 07:47:11 -08:00
Josh Poimboeuf
e476bb277c objtool/klp: Disable unsupported pr_debug() usage
Instead of erroring out on unsupported pr_debug() (e.g., when patching a
module), issue a warning and make it inert, similar to how unsupported
tracepoints are currently handled.

Reviewed-and-tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/3a7db3a5b7d4abf9b2534803a74e2e7231322738.1770759954.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 07:47:11 -08:00
Josh Poimboeuf
f9fb44b0ec objtool/klp: Fix detection of corrupt static branch/call entries
Patching a function which references a static key living in a kernel
module is unsupported due to ordering issues inherent to late module
patching:

  1) Load a livepatch module which has a __jump_table entry which needs
     a klp reloc to reference static key K which lives in module M.

  2) The __jump_table klp reloc does *not* get resolved because module M
     is not yet loaded.

  3) jump_label_add_module() corrupts memory (or causes a panic) when
     dereferencing the uninitialized pointer to key K.

validate_special_section_klp_reloc() intends to prevent that from ever
happening by catching it at build time.  However, it incorrectly assumes
the special section entry's reloc symbol references have already been
converted from section symbols to object symbols, causing the validation
to miss corruption in extracted static branch/call table entries.

Make sure the references have been properly converted before doing the
validation.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Reported-by: Song Liu <song@kernel.org>
Reviewed-and-tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/124ad747b751df0df1725eff89de8332e3fb26d6.1770759954.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-03-06 07:47:10 -08:00
Nathan Chancellor
fdb12c8a24
kbuild: Leave objtool binary around with 'make clean'
The difference between 'make clean' and 'make mrproper' is documented in
'make help' as:

  clean     - Remove most generated files but keep the config and
              enough build support to build external modules
  mrproper  - Remove all generated files + config + various backup files

After commit 68b4fe32d7 ("kbuild: Add objtool to top-level clean
target"), running 'make clean' then attempting to build an external
module with the resulting build directory fails with

  $ make ARCH=x86_64 O=build clean

  $ make -C build M=... MO=...
  ...
  /bin/sh: line 1: .../build/tools/objtool/objtool: No such file or directory

as 'make clean' removes the objtool binary.

Split the objtool clean target into mrproper and clean like Kbuild does
and remove all generated artifacts with 'make clean' except for the
objtool binary, which is removed with 'make mrproper'. To avoid a small
race when running the objtool clean target through both objtool_mrproper
and objtool_clean when running 'make mrproper', modify objtool's clean
up find command to avoid using find's '-delete' command by piping the
files into 'xargs rm -f' like the rest of Kbuild does.

Cc: stable@vger.kernel.org
Fixes: 68b4fe32d7 ("kbuild: Add objtool to top-level clean target")
Reported-by: Michal Suchanek <msuchanek@suse.de>
Closes: https://lore.kernel.org/20260225112633.6123-1-msuchanek@suse.de/
Reported-by: Rainer Fiebig <jrf@mailbox.org>
Closes: https://lore.kernel.org/62d12399-76e5-3d40-126a-7490b4795b17@mailbox.org/
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Tested-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260227-avoid-objtool-binary-removal-clean-v1-1-122f3e55eae9@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-03-02 14:22:39 -07:00
Linus Torvalds
1dd419145d Rust fixes for v7.0-rc1
Toolchain and infrastructure:
 
  - Pass '-Zunstable-options' flag required by the future Rust 1.95.0.
 
  - Fix 'objtool' warning for Rust 1.84.0.
 
 'kernel' crate:
 
  - 'irq' module: add missing bound detected by the future Rust 1.95.0.
 
  - 'list' module: add missing 'unsafe' blocks and placeholder safety
    comments to macros (an issue for future callers within the crate).
 
 'pin-init' crate:
 
  - Clean Clippy warning that changed behavior in the future Rust 1.95.0.
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Merge tag 'rust-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Pass '-Zunstable-options' flag required by the future Rust 1.95.0

   - Fix 'objtool' warning for Rust 1.84.0

  'kernel' crate:

   - 'irq' module: add missing bound detected by the future Rust 1.95.0

   - 'list' module: add missing 'unsafe' blocks and placeholder safety
     comments to macros (an issue for future callers within the crate)

  'pin-init' crate:

   - Clean Clippy warning that changed behavior in the future Rust
     1.95.0"

* tag 'rust-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
  rust: list: Add unsafe blocks for container_of and safety comments
  rust: pin-init: replace clippy `expect` with `allow`
  rust: irq: add `'static` bounds to irq callbacks
  objtool/rust: add one more `noreturn` Rust function
  rust: kbuild: pass `-Zunstable-options` for Rust 1.95.0
2026-02-22 08:43:31 -08:00
Linus Torvalds
956b9cbd7f First round of Kbuild fixes for 7.0
- Ensure tools/objtool is cleaned by 'make clean' and 'make mrproper'
 
 - Fix test program for CONFIG_CC_CAN_LINK to avoid a warning, which is
   made fatal by -Werror
 
 - Drop explicit LZMA parallel compression in scripts/make_fit.py
 
 - Several fixes for commit 62089b8048 ("kbuild: rpm-pkg: Generate
   debuginfo package manually")
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Merge tag 'kbuild-fixes-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild fixes from Nathan Chancellor:

 - Ensure tools/objtool is cleaned by 'make clean' and 'make mrproper'

 - Fix test program for CONFIG_CC_CAN_LINK to avoid a warning, which is
   made fatal by -Werror

 - Drop explicit LZMA parallel compression in scripts/make_fit.py

 - Several fixes for commit 62089b8048 ("kbuild: rpm-pkg: Generate
   debuginfo package manually")

* tag 'kbuild-fixes-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: rpm-pkg: Disable automatic requires for manual debuginfo package
  kbuild: rpm-pkg: Fix manual debuginfo generation when using .src.rpm
  kernel: rpm-pkg: Restore find-debuginfo.sh approach to -debuginfo package
  kbuild: rpm-pkg: Restrict manual debug package creation
  scripts/make_fit.py: Drop explicit LZMA parallel compression
  kbuild: Fix CC_CAN_LINK detection
  kbuild: Add objtool to top-level clean target
2026-02-18 14:59:55 -08:00
Josh Poimboeuf
68b4fe32d7
kbuild: Add objtool to top-level clean target
Objtool is an integral part of the build, make sure it gets cleaned by
"make clean" and "make mrproper".

Fixes: 442f04c34a ("objtool: Add tool to perform compile-time stack metadata validation")
Reported-by: Jens Remus <jremus@linux.ibm.com>
Closes: https://lore.kernel.org/15f2af3b-be33-46fc-b972-6b8e7e0aa52e@linux.ibm.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Tested-by: Jens Remus <jremus@linux.ibm.com>
Link: https://patch.msgid.link/968faf2ed30fa8b3519f79f01a1ecfe7929553e5.1770759919.git.jpoimboe@kernel.org
[nathan: use Closes: instead of Link: per checkpatch.pl]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-02-12 11:30:20 -05:00
Linus Torvalds
57cb845067 - A nice cleanup to the paravirt code containing a unification of the paravirt
clock interface, taming the include hell by splitting the pv_ops structure
   and removing of a bunch of obsolete code. Work by Juergen Gross.
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Merge tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 paravirt updates from Borislav Petkov:

 - A nice cleanup to the paravirt code containing a unification of the
   paravirt clock interface, taming the include hell by splitting the
   pv_ops structure and removing of a bunch of obsolete code (Juergen
   Gross)

* tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted()
  x86/paravirt: Remove trailing semicolons from alternative asm templates
  x86/pvlocks: Move paravirt spinlock functions into own header
  x86/paravirt: Specify pv_ops array in paravirt macros
  x86/paravirt: Allow pv-calls outside paravirt.h
  objtool: Allow multiple pv_ops arrays
  x86/xen: Drop xen_mmu_ops
  x86/xen: Drop xen_cpu_ops
  x86/xen: Drop xen_irq_ops
  x86/paravirt: Move pv_native_*() prototypes to paravirt.c
  x86/paravirt: Introduce new paravirt-base.h header
  x86/paravirt: Move paravirt_sched_clock() related code into tsc.c
  x86/paravirt: Use common code for paravirt_steal_clock()
  riscv/paravirt: Use common code for paravirt_steal_clock()
  loongarch/paravirt: Use common code for paravirt_steal_clock()
  arm64/paravirt: Use common code for paravirt_steal_clock()
  arm/paravirt: Use common code for paravirt_steal_clock()
  sched: Move clock related paravirt code to kernel/sched
  paravirt: Remove asm/paravirt_api_clock.h
  x86/paravirt: Move thunk macros to paravirt_types.h
  ...
2026-02-10 19:01:45 -08:00
Miguel Ojeda
c431b00ca6 objtool/rust: add one more noreturn Rust function
`objtool` with Rust 1.84.0 reports:

    rust/kernel.o: error: objtool: _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix14from_str_radix()
    falls through to next function _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix16from_u64_negated()

This is very similar to commit c18f35e490 ("objtool/rust: add one more
`noreturn` Rust function"), which added `from_ascii_radix_panic` for Rust
1.86.0, except that Rust 1.84.0 ends up needing `from_str_radix_panic`.

Thus add it to the list to fix the warning.

Cc: FUJITA Tomonori <fujita.tomonori@gmail.com>
Fixes: 51d9ee90ea ("rust: str: add radix prefixed integer parsing functions")
Reported-by: Alice Ryhl <aliceryhl@google.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/with/572427627
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260206204336.38462-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-02-10 11:01:16 +01:00
Linus Torvalds
7e0b172c80 Misc objtool fixes:
- Bump up the Clang minimum version requirements
    for livepatch builds, due to Clang assembler
    section handling bugs causing silent
    miscompilations.
 
  - Strip livepatching symbol artifacts from
    non-livepatch modules.
 
  - Fix livepatch build warnings when certain
    Clang LTO options are enabled.
 
  - Fix livepatch build error when
    CONFIG_MEM_ALLOC_PROFILING_DEBUG=y.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-urgent-2026-02-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar::

 - Bump up the Clang minimum version requirements for livepatch
   builds, due to Clang assembler section handling bugs causing
   silent miscompilations

 - Strip livepatching symbol artifacts from non-livepatch modules

 - Fix livepatch build warnings when certain Clang LTO options
   are enabled

 - Fix livepatch build error when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y

* tag 'objtool-urgent-2026-02-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool/klp: Fix unexported static call key access for manually built livepatch modules
  objtool/klp: Fix symbol correlation for orphaned local symbols
  livepatch: Free klp_{object,func}_ext data after initialization
  livepatch: Fix having __klp_objects relics in non-livepatch modules
  livepatch/klp-build: Require Clang assembler >= 20
2026-02-07 08:21:21 -08:00
Josh Poimboeuf
f495054bd1 objtool/klp: Fix unexported static call key access for manually built livepatch modules
Enabling CONFIG_MEM_ALLOC_PROFILING_DEBUG with CONFIG_SAMPLE_LIVEPATCH
results in the following error:

  samples/livepatch/livepatch-shadow-fix1.o: error: objtool: static_call: can't find static_call_key symbol: __SCK__WARN_trap

This is caused an extra file->klp sanity check which was added by commit
164c9201e1 ("objtool: Add base objtool support for livepatch
modules").  That check was intended to ensure that livepatch modules
built with klp-build always have full access to their static call keys.

However, it failed to account for the fact that manually built livepatch
modules (i.e., not built with klp-build) might need access to unexported
static call keys, for which read-only access is typically allowed for
modules.

While the livepatch-shadow-fix1 module doesn't explicitly use any static
calls, it does have a memory allocation, which can cause
CONFIG_MEM_ALLOC_PROFILING_DEBUG to insert a WARN() call.  And WARN() is
now an unexported static call as of commit 860238af7a ("x86_64/bug:
Inline the UD1").

Fix it by removing the overzealous file->klp check, restoring the
original behavior for manually built livepatch modules.

Fixes: 164c9201e1 ("objtool: Add base objtool support for livepatch modules")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Song Liu <song@kernel.org>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/0bd3ae9a53c3d743417fe842b740a7720e2bcd1c.1770058775.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-02-05 08:00:45 -08:00
Josh Poimboeuf
18328546dd objtool/klp: Fix symbol correlation for orphaned local symbols
When compiling with CONFIG_LTO_CLANG_THIN, vmlinux.o has
__irf_[start|end] before the first FILE entry:

  $ readelf -sW vmlinux.o
  Symbol table '.symtab' contains 597706 entries:
     Num:    Value          Size Type    Bind   Vis      Ndx Name
       0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
       1: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT   18 __irf_start
       2: 0000000000000200     0 NOTYPE  LOCAL  DEFAULT   18 __irf_end
       3: 0000000000000000     0 SECTION LOCAL  DEFAULT   17 .text
       4: 0000000000000000     0 SECTION LOCAL  DEFAULT   18 .init.ramfs

This causes klp-build warnings like:

  vmlinux.o: warning: objtool: no correlation: __irf_start
  vmlinux.o: warning: objtool: no correlation: __irf_end

The problem is that Clang LTO is stripping the initramfs_data.o FILE
symbol, causing those two symbols to be orphaned and not noticed by
klp-diff's correlation logic.  Add a loop to correlate any symbols found
before the first FILE symbol.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Reported-by: Song Liu <song@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/e21ec1141fc749b5f538d7329b531c1ab63a6d1a.1770055235.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-02-05 08:00:45 -08:00
Petr Pavlu
b525fcaf0a livepatch: Free klp_{object,func}_ext data after initialization
The klp_object_ext and klp_func_ext data, which are stored in the
__klp_objects and __klp_funcs sections, respectively, are not needed
after they are used to create the actual klp_object and klp_func
instances. This operation is implemented by the init function in
scripts/livepatch/init.c.

Prefix the two sections with ".init" so they are freed after the module
is initializated.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Link: https://patch.msgid.link/20260123102825.3521961-3-petr.pavlu@suse.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-02-05 08:00:45 -08:00
Linus Torvalds
969b5726ac Miscellaneous objtool fixes:
- Fix a build error on ia32-x86_64 cross builds
 
  - Replace locally open coded ALIGN_UP(), ALIGN_UP_POW2()
    and MAX(), which, beyond being duplicates, the
    ALIGN_UP_POW2() is also buggy.
 
  - Fix objtool klp-diff regression caused by a recent
    change to the bug table format.
 
  - Fix klp-build vs CONFIG_MODULE_SRCVERSION_ALL build
    failure.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-urgent-2026-02-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar:

 - Fix a build error on ia32-x86_64 cross builds

 - Replace locally open coded ALIGN_UP(), ALIGN_UP_POW2()
   and MAX(), which, beyond being duplicates, the
   ALIGN_UP_POW2() is also buggy

 - Fix objtool klp-diff regression caused by a recent
   change to the bug table format

 - Fix klp-build vs CONFIG_MODULE_SRCVERSION_ALL build
   failure

* tag 'objtool-urgent-2026-02-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  livepatch/klp-build: Fix klp-build vs CONFIG_MODULE_SRCVERSION_ALL
  objtool/klp: Fix bug table handling for __WARN_printf()
  objtool: Replace custom macros in elf.c with shared ones
  objtool: Print bfd_vma as unsigned long long on ia32-x86_64 cross build
2026-02-01 10:27:43 -08:00
Linus Torvalds
367b81ef01 Rust fixes for v6.19
Toolchain and infrastructure:
 
   - Trigger rebuilds of the newly added 'proc-macro2' crate (and its
     dependencies) when the Rust compiler version changes.
 
   - Fix error in '.rsi' targets (macro expanding single targets) under
     'O=' pointing to an external (not subdir) folder.
 
   - Fix off-by-one line number in 'rustdoc' KUnit tests.
 
   - Add '-fdiagnostics-show-context' to GCC flags skipped by 'bindgen'.
 
   - Clean objtool warning by adding one more 'noreturn' function.
 
   - Clean 'libpin_init_internal.{so,dylib}' in 'mrproper'.
 
 'kernel' crate:
 
   - Fix build error when using expressions in formatting arguments.
 
   - Mark 'num::Bounded::__new()' as unsafe and clean documentation
     accordingly.
 
   - Always inline functions using 'build_assert' with arguments.
 
   - Fix 'rusttest' build error providing the right 'isize_atomic_repr'
     type for the host.
 
 'macros' crate:
 
   - Fix 'rusttest' build error by ignoring example.
 
 rust-analyzer:
 
   - Remove assertion that was not true for distributions like NixOS.
 
   - Add missing dependency edges and fix editions for 'quote' and
     sysroot crates to provide correct IDE support.
 
 DRM Tyr:
 
   - Fix build error by adding missing dependency on 'CONFIG_COMMON_CLK'.
 
 Plus clean a few typos in docs and comments.
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Merge tag 'rust-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Trigger rebuilds of the newly added 'proc-macro2' crate (and its
     dependencies) when the Rust compiler version changes

   - Fix error in '.rsi' targets (macro expanding single targets) under
     'O=' pointing to an external (not subdir) folder

   - Fix off-by-one line number in 'rustdoc' KUnit tests

   - Add '-fdiagnostics-show-context' to GCC flags skipped by 'bindgen'

   - Clean objtool warning by adding one more 'noreturn' function

   - Clean 'libpin_init_internal.{so,dylib}' in 'mrproper'

  'kernel' crate:

   - Fix build error when using expressions in formatting arguments

   - Mark 'num::Bounded::__new()' as unsafe and clean documentation
     accordingly

   - Always inline functions using 'build_assert' with arguments

   - Fix 'rusttest' build error providing the right 'isize_atomic_repr'
     type for the host

  'macros' crate:

   - Fix 'rusttest' build error by ignoring example

  rust-analyzer:

   - Remove assertion that was not true for distributions like NixOS

   - Add missing dependency edges and fix editions for 'quote' and
     sysroot crates to provide correct IDE support

  DRM Tyr:

   - Fix build error by adding missing dependency on 'CONFIG_COMMON_CLK'

  Plus clean a few typos in docs and comments"

* tag 'rust-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (28 commits)
  rust: num: bounded: clean __new documentation and comments
  scripts: generate_rust_analyzer: fix resolution of #[pin_data] macros
  drm/tyr: depend on `COMMON_CLK` to fix build error
  rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts
  kbuild: rust: clean libpin_init_internal in mrproper
  rust: proc-macro2: rebuild if the version text changes
  rust: num: bounded: add missing comment for always inlined function
  rust: sync: refcount: always inline functions using build_assert with arguments
  rust: bits: always inline functions using build_assert with arguments
  scripts: generate_rust_analyzer: compile sysroot with correct edition
  scripts: generate_rust_analyzer: compile quote with correct edition
  scripts: generate_rust_analyzer: quote: treat `core` and `std` as dependencies
  scripts: generate_rust_analyzer: syn: treat `std` as a dependency
  scripts: generate_rust_analyzer: remove sysroot assertion
  rust: kbuild: give `--config-path` to `rustfmt` in `.rsi` target
  scripts: generate_rust_analyzer: Add pin_init_internal deps
  scripts: generate_rust_analyzer: Add pin_init -> compiler_builtins dep
  scripts: generate_rust_analyzer: Add compiler_builtins -> core dep
  rust: macros: ignore example with module parameters
  rust: num: bounded: mark __new as unsafe
  ...
2026-01-30 16:15:59 -08:00
Josh Poimboeuf
f2dba60339 objtool/klp: Fix bug table handling for __WARN_printf()
Running objtool klp-diff on a changed function which uses WARN() can
fail with:

  vmlinux.o: error: objtool: md_run+0x866: failed to convert reloc sym '__bug_table' to its proper format

The problem is that since commit 5b472b6e5b ("x86_64/bug: Implement
__WARN_printf()"), each __WARN_printf() call site now directly
references its bug table entry.  klp-diff errors out when it can't
convert such section-based references to object symbols (because bug
table entries don't have symbols).

Luckily, klp-diff already has code to create symbols for bug table
entries.  Move that code earlier, before function diffing.

Fixes: dd590d4d57 ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Fixes: 5b472b6e5b ("x86_64/bug: Implement __WARN_printf()")
Reported-by: Song Liu <song@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/a8e0a714b9da962858842b9aecd63b4900927c88.1769406850.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-01-27 08:20:47 -08:00
Petr Pavlu
d107b3265a objtool: Replace custom macros in elf.c with shared ones
The source file tools/objtool/elf.c defines the macros ALIGN_UP(),
ALIGN_UP_POW2() and MAX(). These macros unnecessarily duplicate
functionality already available under tools/include/, specifically ALIGN(),
roundup_pow_of_two() and max().

More importantly, the definition of ALIGN_UP_POW2() is incorrect when the
input is 1, as it results in a call to __builtin_clz(0), which produces an
undefined result. This issue impacts the function elf_alloc_reloc(). When
adding the first relocation to a section, the function allocates an
undefined number of relocations.

Replace the custom macros with the shared functionality to resolve these
issues.

Fixes: 2c05ca0262 ("objtool: Add elf_create_reloc() and elf_init_reloc()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://patch.msgid.link/20260126151356.3924887-1-petr.pavlu@suse.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-01-27 08:20:41 -08:00
Dmitry Safonov
fd4eeb30b9 objtool: Print bfd_vma as unsigned long long on ia32-x86_64 cross build
When objtool is cross-compiled in ia32 container for x86_64 target it
fails with the following errors:

> disas.c: In function 'disas_print_addr_sym':
> disas.c:173:38: error: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'bfd_vma' {aka 'long long unsigned int'} [-Werror=format=]
>   173 |                 DINFO_FPRINTF(dinfo, "0x%lx <%s>", addr, symstr);
>       |                                      ^~~~~~~~~~~~  ~~~~
>       |                                                    |
>       |                                                    bfd_vma {aka long long unsigned int}

Provide a correct printf-fmt depending on sizeof(bfd_vma).

Fixes: 5d859dff26 ("objtool: Print symbol during disassembly")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://patch.msgid.link/20260126-objtool-ia32-v1-1-bb6feaf17566@arista.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-01-27 08:19:35 -08:00
Sasha Levin
3f2de814c0 objtool: Fix libopcodes linking with static libraries
Commit 436326bc52 ("objtool: fix build failure due to missing libopcodes
check") tests for libopcodes using an empty main(), which passes even when
static libraries lack their dependencies. This causes undefined reference
errors (xmalloc, bfd_get_bits, etc.) when linking against static libopcodes
without its required libbfd and libiberty.

Fix by testing with an actual libopcodes symbol and trying increasingly
complete library combinations until one succeeds.

Fixes: 436326bc52 ("objtool: fix build failure due to missing libopcodes check")
Reported-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Link: https://patch.msgid.link/20260121162532.1596238-1-sashal@kernel.org
2026-01-21 20:25:14 +01:00
Juergen Gross
b0b449e6fe x86/pvlocks: Move paravirt spinlock functions into own header
Instead of having the pv spinlock function definitions in paravirt.h,
move them into the new header paravirt-spinlock.h.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260105110520.21356-22-jgross@suse.com
2026-01-13 14:57:45 +01:00
Juergen Gross
f88dc319fc objtool: Allow multiple pv_ops arrays
Having a single large pv_ops array has the main disadvantage of needing all
prototypes of the single array members in one header file. This is adding up
to the need to include lots of otherwise unrelated headers.

In order to allow multiple smaller pv_ops arrays dedicated to one area of the
kernel each, allow multiple arrays in objtool.

For better performance limit the possible names of the arrays to start with
"pv_ops".

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260105110520.21356-19-jgross@suse.com
2026-01-13 13:39:49 +01:00
Sasha Levin
436326bc52 objtool: fix build failure due to missing libopcodes check
Commit 5995330382 ("objtool: Disassemble code with libopcodes instead
of running objdump") added support for using libopcodes for disassembly.
However, the feature detection checks for libbfd availability but then
unconditionally links against libopcodes:

  ifeq ($(feature-libbfd),1)
      OBJTOOL_LDFLAGS += -lopcodes
  endif

This causes build failures in environments where libbfd is installed but
libopcodes is not, since the test-libbfd.c feature test only links
against -lbfd and -ldl, not -lopcodes:

  /usr/bin/ld: cannot find -lopcodes: No such file or directory
  collect2: error: ld returned 1 exit status
  make[4]: *** [Makefile:109: objtool] Error 1

Additionally, the shared feature framework uses $(CC) which is the
cross-compiler in cross-compilation builds. Since objtool is a host tool
that links with $(HOSTCC) against host libraries, the feature detection
can falsely report libopcodes as available when the cross-compiler's
sysroot has it but the host system doesn't.

Fix this by replacing the feature framework check with a direct inline
test that uses $(HOSTCC) to compile and link a test program against
libopcodes, similar to how xxhash availability is detected.

Fixes: 5995330382 ("objtool: Disassemble code with libopcodes instead of running objdump")
Assisted-by: claude-opus-4-5-20251101
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251223120357.2492008-1-sashal@kernel.org
2026-01-13 11:37:51 +01:00
Mikulas Patocka
26bea10450 objtool: fix compilation failure with the x32 toolchain
When using the x32 toolchain, compilation fails because the printf
specifier "%lx" (long), doesn't match the type of the "checksum" variable
(long long). Fix this by changing the printf specifier to "%llx" and
casting "checksum" to unsigned long long.

Fixes: a3493b3338 ("objtool/klp: Add --debug-checksum=<funcs> to show per-instruction checksums")

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/a1158c99-fe0e-a218-4b5b-ffac212489f6@redhat.com
2026-01-13 11:37:50 +01:00
Juergen Gross
7aef17f367 x86/xen: Drop xen_mmu_ops
Instead of having a pre-filled array xen_mmu_ops for Xen PV paravirt
functions, drop the array and assign each element individually.

This is in preparation of reducing the paravirt include hell by
splitting paravirt.h into multiple more fine grained header files,
which will in turn require to split up the pv_ops vector as well.
Dropping the pre-filled array makes life easier for objtool to
detect missing initializers in multiple pv_ops_ arrays.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://patch.msgid.link/20260105110520.21356-18-jgross@suse.com
2026-01-12 21:44:34 +01:00
Juergen Gross
817f66e39e x86/xen: Drop xen_cpu_ops
Instead of having a pre-filled array xen_cpu_ops for Xen PV paravirt
functions, drop the array and assign each element individually.

This is in preparation of reducing the paravirt include hell by
splitting paravirt.h into multiple more fine grained header files,
which will in turn require to split up the pv_ops vector as well.
Dropping the pre-filled array makes life easier for objtool to
detect missing initializers in multiple pv_ops_ arrays.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://patch.msgid.link/20260105110520.21356-17-jgross@suse.com
2026-01-12 19:53:20 +01:00
Juergen Gross
bc5e8e2fa2 x86/xen: Drop xen_irq_ops
Instead of having a pre-filled array xen_irq_ops for Xen PV paravirt
functions, drop the array and assign each element individually.

This is in preparation of reducing the paravirt include hell by
splitting paravirt.h into multiple more fine grained header files,
which will in turn require to split up the pv_ops vector as well.
Dropping the pre-filled array makes life easier for objtool to
detect missing initializers in multiple pv_ops_ arrays.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://patch.msgid.link/20260105110520.21356-16-jgross@suse.com
2026-01-12 19:37:38 +01:00
FUJITA Tomonori
c18f35e490 objtool/rust: add one more noreturn Rust function
Fix the following warning:

rust/kernel.o: warning: objtool: _RNvXNtNtCs1ewLyjEZ7Le_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix14from_str_radix()
falls through to next function _RNvXNtNtCs1ewLyjEZ7Le_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix16from_u64_negated()

The commit 51d9ee90ea ("rust: str: add radix prefixed integer
parsing functions") introduces u64::from_str_radix(), whose
implementation contains a panic path for out-of-range radix values.
The panic helper is core::num::from_ascii_radix_panic().

Note that radix is derived from strip_radix() here and is always
within the valid range, so kernel never panics.

Fixes: 51d9ee90ea ("rust: str: add radix prefixed integer parsing functions")
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251223113538.1016078-1-fujita.tomonori@gmail.com
[ Reworded typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-01-04 23:51:35 +01:00
Josh Poimboeuf
799647ddb4 objtool: Add more robust signal error handling, detect and warn about stack overflows
When the kernel build fails due to an objtool segfault, the error
message is a bit obtuse and confusing:

  make[5]: *** [scripts/Makefile.build:503: drivers/scsi/qla2xxx/qla2xxx.o] Error 139
                                                                            ^^^^^^^^^
  make[5]: *** Deleting file 'drivers/scsi/qla2xxx/qla2xxx.o'
  make[4]: *** [scripts/Makefile.build:556: drivers/scsi/qla2xxx] Error 2
  make[3]: *** [scripts/Makefile.build:556: drivers/scsi] Error 2
  make[2]: *** [scripts/Makefile.build:556: drivers] Error 2
  make[1]: *** [/home/jpoimboe/git/linux/Makefile:2013: .] Error 2
  make: *** [Makefile:248: __sub-make] Error 2

Add a signal handler to objtool which prints an error message like if
the local stack has overflown (for which there's a chance as objtool
makes heavy use of recursion):

  drivers/scsi/qla2xxx/qla2xxx.o: error: SIGSEGV: objtool stack overflow!

or:

  drivers/scsi/qla2xxx/qla2xxx.o: error: SIGSEGV: objtool crash!

Also, re-raise the signal so the core dump still gets triggered.

[ mingo: Applied a build fix, added more comments and prettified the code. ]

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: David Laight <david.laight.linux@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/mi4tihk4dbncn7belrhp6ooudhpw4vdggerktu5333w3gqf3uf@vqlhc3y667mg
2025-12-03 19:42:37 +01:00
Josh Poimboeuf
0c314a881c objtool: Fix stack overflow in validate_branch()
On an allmodconfig kernel compiled with Clang, objtool is segfaulting in
drivers/scsi/qla2xxx/qla2xxx.o due to a stack overflow in
validate_branch().

Due in part to KASAN being enabled, the qla2xxx code has a large number
of conditional jumps, causing objtool to go quite deep in its recursion.

By far the biggest offender of stack usage is the recently added
'prev_state' stack variable in validate_insn(), coming in at 328 bytes.

Move that variable (and its tracing usage) to handle_insn_ops() and make
handle_insn_ops() noinline to keep its stack frame outside the recursive
call chain.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Fixes: fcb268b47a ("objtool: Trace instruction state changes during function validation")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/21bb161c23ca0d8c942a960505c0d327ca2dc7dc.1764691895.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/20251201202329.GA3225984@ax162
2025-12-02 17:40:35 +01:00
Ingo Molnar
6ec33db1aa objtool: Fix segfault on unknown alternatives
So 'objtool --link -d vmlinux.o' gets surprised by this endbr64+endbr64 pattern
in ___bpf_prog_run():

	___bpf_prog_run:
	1e7680:  ___bpf_prog_run+0x0                                                     push   %r12
	1e7682:  ___bpf_prog_run+0x2                                                     mov    %rdi,%r12
	1e7685:  ___bpf_prog_run+0x5                                                     push   %rbp
	1e7686:  ___bpf_prog_run+0x6                                                     xor    %ebp,%ebp
	1e7688:  ___bpf_prog_run+0x8                                                     push   %rbx
	1e7689:  ___bpf_prog_run+0x9                                                     mov    %rsi,%rbx
	1e768c:  ___bpf_prog_run+0xc                                                     movzbl (%rbx),%esi
	1e768f:  ___bpf_prog_run+0xf                                                     movzbl %sil,%edx
	1e7693:  ___bpf_prog_run+0x13                                                    mov    %esi,%eax
	1e7695:  ___bpf_prog_run+0x15                                                    mov    0x0(,%rdx,8),%rdx
	1e769d:  ___bpf_prog_run+0x1d                                                    jmp    0x1e76a2 <__x86_indirect_thunk_rdx>
	1e76a2:  ___bpf_prog_run+0x22                                                    endbr64
	1e76a6:  ___bpf_prog_run+0x26                                                    endbr64
	1e76aa:  ___bpf_prog_run+0x2a                                                    mov    0x4(%rbx),%edx

And crashes due to blindly dereferencing alt->insn->alt_group.

Bail out on NULL ->alt_group, which produces this warning and continues
with the disassembly, instead of a segfault:

  .git/O/vmlinux.o: warning: objtool: <alternative.1e769d>: failed to disassemble alternative

Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-12-01 10:42:27 +01:00
Alexandre Chartre
59bfa64082 objtool: Build with disassembly can fail when including bdf.h
Building objtool with disassembly support can fail when including
the bdf.h file:

  In file included from tools/objtool/include/objtool/arch.h:108,
                   from check.c:14:
  /usr/include/bfd.h:35:2: error: #error config.h must be included before this header
     35 | #error config.h must be included before this header
        |  ^~~~~

This check is present in the bfd.h file generated from the binutils
source code, but it is not necessarily present in the bfd.h file
provided in a binutil package (for example, it is not present in
the binutil RPM).

The solution to this issue is to define the PACKAGE macro before
including bfd.h. This is the solution suggested by the binutil
developer in bug 14243, and it is used by other kernel tools
which also use bfd.h (perf and bpf).

Fixes: 5995330382 ("objtool: Disassemble code with libopcodes instead of running objdump")
Closes: https://lore.kernel.org/all/3fa261fd-3b46-4cbe-b48d-7503aabc96cb@oracle.com/
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=14243
Link: https://patch.msgid.link/20251126134519.1760889-1-alexandre.chartre@oracle.com
2025-11-27 09:32:46 +01:00
Alexandre Chartre
c0a67900dc objtool: Trim trailing NOPs in alternative
When disassembling alternatives replace trailing NOPs with a single
indication of the number of bytes covered with NOPs.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-31-alexandre.chartre@oracle.com
2025-11-24 20:40:48 +01:00
Alexandre Chartre
aff95e0d4e objtool: Add wide output for disassembly
Add the --wide option to provide a wide output when disassembling.
With this option, the disassembly of alternatives is displayed
side-by-side instead of one above the other.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-30-alexandre.chartre@oracle.com
2025-11-24 20:40:48 +01:00
Alexandre Chartre
07d70b271a objtool: Compact output for alternatives with one instruction
When disassembling, if an instruction has alternatives which are all
made of a single instruction then print each alternative on a single
line (instruction + description) so that the output is more compact.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-29-alexandre.chartre@oracle.com
2025-11-24 20:40:48 +01:00
Alexandre Chartre
56967b9a77 objtool: Improve naming of group alternatives
Improve the naming of group alternatives by showing the feature name and
flags used by the alternative.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-28-alexandre.chartre@oracle.com
2025-11-24 20:40:48 +01:00
Alexandre Chartre
8308fd0019 objtool: Add Function to get the name of a CPU feature
Add a function to get the name of a CPU feature. The function is
architecture dependent and currently only implemented for x86. The
feature names are automatically generated from the cpufeatures.h
include file.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-27-alexandre.chartre@oracle.com
2025-11-24 20:39:47 +01:00
Alexandre Chartre
be5ee60ac5 objtool: Provide access to feature and flags of group alternatives
Each alternative of a group alternative depends on a specific
feature and flags. Provide access to the feature/flags for each
alternative as an attribute (feature) in struct alt_group.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-26-alexandre.chartre@oracle.com
2025-11-21 15:30:14 +01:00
Alexandre Chartre
4aae0d3f77 objtool: Fix address references in alternatives
When using the --disas option, alternatives are disassembled but
address references in non-default alternatives can be incorrect.

The problem is that alternatives are shown as if they were replacing the
original code of the alternative. So if an alternative is referencing
an address inside the alternative then the reference has to be
adjusted to the location of the original code.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-25-alexandre.chartre@oracle.com
2025-11-21 15:30:14 +01:00
Alexandre Chartre
7e017720aa objtool: Disassemble jump table alternatives
When using the --disas option, also disassemble jump tables.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-24-alexandre.chartre@oracle.com
2025-11-21 15:30:14 +01:00
Alexandre Chartre
78df4590c5 objtool: Disassemble exception table alternatives
When using the --disas option, also disassemble exception tables
(EX_TABLE).

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-23-alexandre.chartre@oracle.com
2025-11-21 15:30:14 +01:00
Alexandre Chartre
15e7ad8667 objtool: Print addresses with alternative instructions
All alternatives are disassemble side-by-side when using the --disas
option. However the address of each instruction is not printed because
instructions from different alternatives are not necessarily aligned.

Change this behavior to print the address of each instruction. Spaces
will appear between instructions from the same alternative when
instructions from different alternatives do not have the same alignment.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-22-alexandre.chartre@oracle.com
2025-11-21 15:30:13 +01:00
Alexandre Chartre
a4f1599672 objtool: Disassemble group alternatives
When using the --disas option, disassemble all group alternatives.
Jump tables and exception tables (which are handled as alternatives)
are not disassembled at the moment.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-21-alexandre.chartre@oracle.com
2025-11-21 15:30:13 +01:00
Alexandre Chartre
87343e6642 objtool: Print headers for alternatives
When using the --disas option, objtool doesn't currently disassemble
any alternative. Print an header for each alternative. This identifies
places where alternatives are present but alternative code is still
not disassembled at the moment.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-20-alexandre.chartre@oracle.com
2025-11-21 15:30:13 +01:00
Alexandre Chartre
7ad7a4a720 objtool: Preserve alternatives order
Preserve the order in which alternatives are defined. Currently
objtool stores alternatives in a list in reverse order.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-19-alexandre.chartre@oracle.com
2025-11-21 15:30:12 +01:00
Alexandre Chartre
5f326c8897 objtool: Add the --disas=<function-pattern> action
Add the --disas=<function-pattern> actions to disassemble the specified
functions. The function pattern can be a single function name (e.g.
--disas foo to disassemble the function with the name "foo"), or a shell
wildcard pattern (e.g. --disas foo* to disassemble all functions with a
name starting with "foo").

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-18-alexandre.chartre@oracle.com
2025-11-21 15:30:12 +01:00
Alexandre Chartre
c3b7d044fc objtool: Do not validate IBT for .return_sites and .call_sites
The .return_sites and .call_sites sections reference text addresses,
but not with the intent to indirect branch to them, so they don't
need to be validated for IBT.

This is useful when running objtool on object files which already
have .return_sites or .call_sites sections, for example to re-run
objtool after it has reported an error or a warning.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-17-alexandre.chartre@oracle.com
2025-11-21 15:30:12 +01:00
Alexandre Chartre
350c7ab857 objtool: Improve tracing of alternative instructions
When tracing function validation, improve the reporting of
alternative instruction by more clearly showing the different
alternatives beginning and end.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-16-alexandre.chartre@oracle.com
2025-11-21 15:30:11 +01:00
Alexandre Chartre
9b580accac objtool: Add functions to better name alternatives
Add the disas_alt_name() and disas_alt_type_name() to provide a
name and a type name for an alternative. This will be used to
better name alternatives when tracing their execution.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-15-alexandre.chartre@oracle.com
2025-11-21 15:30:11 +01:00
Alexandre Chartre
d490aa2197 objtool: Identify the different types of alternatives
Alternative code, including jump table and exception table, is represented
with the same struct alternative structure. But there is no obvious way to
identify whether the struct represents alternative instructions, a jump
table or an exception table.

So add a type to struct alternative to clearly identify the type of
alternative.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-14-alexandre.chartre@oracle.com
2025-11-21 15:30:11 +01:00
Alexandre Chartre
26a453fb56 objtool: Improve register reporting during function validation
When tracing function validation, instruction state changes can
report changes involving registers. These registers are reported
with the name "r<num>" (e.g. "r3"). Print the CPU specific register
name instead of a generic name (e.g. print "rbx" instead of "r3"
on x86).

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-13-alexandre.chartre@oracle.com
2025-11-21 15:30:10 +01:00
Alexandre Chartre
fcb268b47a objtool: Trace instruction state changes during function validation
During function validation, objtool maintains a per-instruction state,
in particular to track call frame information. When tracing validation,
print any instruction state changes.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-12-alexandre.chartre@oracle.com
2025-11-21 15:30:10 +01:00
Alexandre Chartre
70589843b3 objtool: Add option to trace function validation
Add an option to trace and have information during the validation
of specified functions. Functions are specified with the --trace
option which can be a single function name (e.g. --trace foo to
trace the function with the name "foo"), or a shell wildcard
pattern (e.g. --trace foo* to trace all functions with a name
starting with "foo").

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-11-alexandre.chartre@oracle.com
2025-11-21 15:30:09 +01:00
Alexandre Chartre
de0248fbbf objtool: Record symbol name max length
Keep track of the maximum length of symbol names. This will help
formatting the code flow between different functions.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-10-alexandre.chartre@oracle.com
2025-11-21 15:30:09 +01:00
Alexandre Chartre
a0e5bf9fd6 objtool: Extract code to validate instruction from the validate branch loop
The code to validate a branch loops through all instructions of the
branch and validate each instruction. Move the code to validate an
instruction to a separated function.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-9-alexandre.chartre@oracle.com
2025-11-21 15:30:08 +01:00
Alexandre Chartre
0bb080ba64 objtool: Disassemble instruction on warning or backtrace
When an instruction warning (WARN_INSN) or backtrace (BT_INSN) is issued,
disassemble the instruction to provide more context.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-8-alexandre.chartre@oracle.com
2025-11-21 15:30:08 +01:00
Alexandre Chartre
d4e13c2149 objtool: Store instruction disassembly result
When disassembling an instruction store the result instead of directly
printing it.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-7-alexandre.chartre@oracle.com
2025-11-21 15:30:08 +01:00
Alexandre Chartre
5d859dff26 objtool: Print symbol during disassembly
Print symbols referenced during disassembly instead of just printing
raw addresses. Also handle address relocation.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-6-alexandre.chartre@oracle.com
2025-11-21 15:30:07 +01:00
Alexandre Chartre
5995330382 objtool: Disassemble code with libopcodes instead of running objdump
objtool executes the objdump command to disassemble code. Use libopcodes
instead to have more control about the disassembly scope and output.
If libopcodes is not present then objtool is built without disassembly
support.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-4-alexandre.chartre@oracle.com
2025-11-21 15:30:07 +01:00
Alexandre Chartre
1013f2e37b objtool: Create disassembly context
Create a structure to store information for disassembling functions.
For now, it is just a wrapper around an objtool file.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-3-alexandre.chartre@oracle.com
2025-11-21 15:30:06 +01:00