linux-stable.git/tools/objtool/klp-diff.c, branch v7.1.5

objtool: Replace iterator callback with for_each_sym_by_mangled_name()

2026-07-24T14:19:07+00:00

[ Upstream commit 0333b7399587ee0aaa863ed0d13a00a6c7c64068 ]

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 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Stable-dep-of: a375e327b63e ("objtool: Fix reloc hash collision in find_reloc_by_dest_range()")
Signed-off-by: Sasha Levin

objtool/klp: Fix relocation conversion failures for R_X86_64_NONE

2026-07-24T14:19:07+00:00

[ Upstream commit 3787e82a4e3a0a04aeb5543580ee90bed3a36e55 ]

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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

objtool/klp: Fix extraction of text annotations for alternatives

2026-07-24T14:19:07+00:00

[ Upstream commit 62a7a01fde87c99926cd7e9670b4226c4c79ebaf ]

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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

objtool/klp: Fix cloning of zero-length section symbols

2026-07-24T14:19:07+00:00

[ Upstream commit 98377f3ba7c02d6eb34e203c9f9823bc62b0d231 ]

Fix NULL dereference when cloning a symbol from an empty section.
sec->data is only populated for sections with non-zero size.

Fixes: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

objtool/klp: Fix handling of zero-length .altinstr_replacement sections

2026-07-24T14:19:07+00:00

[ Upstream commit c4c02d4450b5b7e2fbde578252f71a5697180112 ]

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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

objtool/klp: Fix create_fake_symbols() skipping entsize-based sections

2026-07-24T14:19:07+00:00

[ Upstream commit 3de711fba73ad93b8b3fbe09cf681cefed5d573d ]

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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Assisted-by: Claude:claude-4-opus
Signed-off-by: Joe Lawrence 
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

objtool/klp: Fix .data..once static local non-correlation

2026-07-24T14:19:07+00:00

[ Upstream commit ff529864e738f447ff4c019956319930fc274a23 ]

While there was once a section named .data.once, it has since been
renamed to .data..once with commit dbefa1f31a91 ("Rename .data.once to
.data..once to fix resetting WARN*_ONCE").  Fix it.

Fixes: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

objtool/klp: Fix is_uncorrelated_static_local() for Clang

2026-07-24T14:19:07+00:00

[ Upstream commit 84c304a534b844703d3437811e8f072166e3f116 ]

For naming function-local static locals, GCC uses ., e.g.
__already_done.15, while Clang uses . with optional .,
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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Signed-off-by: Joe Lawrence 
Acked-by: Song Liu 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Sasha Levin

Merge tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-04-14T20:00:04+00:00

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

objtool/klp: fix data alignment in __clone_symbol()

2026-03-16T19:39:45+00:00

Commit 356e4b2f5b80 ("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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files")
Signed-off-by: Joe Lawrence 
Link: https://patch.msgid.link/20260310203751.1479229-2-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf