objtool/klp: Some klp-build fixes and improvements

Changes since v1 (https://lore.kernel.org/[email protected]):

- Add comment for find_reloc_by_dest_range() first-match behavior [Peter]
- Simplify is_cold_func() [Peter]
- Grow __cfi_ symbols [Peter]
- Rename "Ignore __UNIQUE_ID_*() PCI stub functions" to more general "Don't report uncorrelated functions as new" [Song]
- Move rodata non-correlation into pointer-comparison fix [Miroslav]
- Add comments for convert_reloc_sym() return values [Song]
- Remove redundant SRC/OBJ variables [Song]
- Use "if (mismatch) {} else" in for_each_sym_by_*() [Song]
- Flatten nested if-else chain in short-circuit validation [Song]
- Add comments with examples to symbol correlation algorithm [Song]
- Move callback refactor to earlier in the patch set [Miroslav]
- Fix reloc corruption in convert_reloc_sym_to_secsym() [Sashiko]
- Include offset in object checksum hashing [Sashiko]
- Fix klp-build checksum comparison output for added/removed instructions [Sashiko]
- Fix kCFI prefix finding/cloning
- Add reloc symbol conversion simplification cleanup
- Improve local label check for uncorrelated symbols
- Drop "Make function prefix handling more generic" for now (refactored version will come with arm64 patches)
- Refactor inline alternative cloning into separate clone_inline_alternatives()
- Add Acked-by/Reviewed-by tags

---

While working on the (upcoming) arm64 support, I ended up shaking out a lot of bugs by tested several patches on a variety of configs (distro, LTO, FineIBT, kCFI, etc).

While arm64 support seems to be working well, I decided to leave those patches out of this set to try to keep the number of patches "reasonable".

And these stand alone as nice improvements for x86 anyway.

Full arm64 support (this set + more) can be found here:

git://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git klp-build-arm64

Joe Lawrence (2):
objtool/klp: Fix is_uncorrelated_static_local() for Clang objtool/klp: Fix create_fake_symbols() skipping entsize-based sections

Josh Poimboeuf (51):
objtool/klp: Fix .data..once static local non-correlation objtool/klp: Don't correlate __ADDRESSABLE() symbols objtool/klp: Don't correlate absolute symbols
objtool/klp: Don't correlate __initstub__ symbols objtool/klp: Don't report uncorrelated functions as new objtool/klp: Improve local label check
objtool: Replace iterator callback with for_each_sym_by_mangled_name() objtool/klp: Fix --debug-checksum for duplicate symbol names objtool/klp: Fix handling of zero-length .altinstr_replacement
sections
objtool/klp: Fix cloning of zero-length section symbols objtool/klp: Fix XXH3 state memory leak
objtool/klp: Fix extraction of text annotations for alternatives objtool/klp: Fix kCFI trap handling
objtool/klp: Fix relocation conversion failures for R_X86_64_NONE
objtool: Move mark_rodata() to elf.c
objtool/klp: Simplify reloc symbol conversion
objtool/klp: Fix pointer comparisons for rodata objects objtool/klp: Don't correlate .rodata.cst* constant pool objects objtool/klp: Fix reloc corruption in convert_reloc_sym_to_secsym()
objtool: Fix reloc hash collision in find_reloc_by_dest_range()
klp-build: Fix hang on out-of-date .config
klp-build: Fix checksum comparison for changed offsets
klp-build: Don't use errexit
klp-build: Validate patch file existence
klp-build: Suppress excessive fuzz output by default
klp-build: Fix patch cleanup on interrupt
klp-build: Reject patches to vDSO
klp-build: Reject patches to realmode
klp-build: Print "objtool klp diff" command in verbose mode
klp-build: Remove redundant SRC and OBJ variables objtool/klp: Don't set sym->file for section symbols
objtool: Include libsubcmd headers directly from source tree objtool/klp: Create empty checksum sections for function-less object
files
objtool/klp: Handle Clang .data..Lanon anonymous data sections
objtool: Add is_alias_sym() helper
objtool: Add is_cold_func() helper
objtool/klp: Extricate checksum calculation from validate_branch()
objtool: Consolidate file decoding into decode_file() objtool/klp: Add "objtool klp checksum" subcommand
klp-build: Use "objtool klp checksum" subcommand objtool/klp: Remove "objtool --checksum"
klp-build: Validate short-circuit prerequisites objtool/klp: Calculate object checksums
objtool/klp: Rewrite symbol correlation algorithm objtool/klp: Add correlation debugging output
objtool: Add insn_sym() helper
objtool/klp: Fix position-dependent checksums for non-relocated
jumps/calls
objtool: Grow __cfi_* prefix symbols for all CFI+CALL_PADDING objtool/klp: Fix kCFI prefix finding/cloning
objtool: Improve and simplify prefix symbol detection objtool/klp: Cache dont_correlate() result

 arch/x86/Kconfig                         |   4 -
 lib/Kconfig.debug                        |   2 +-
 scripts/Makefile.lib                     |   7 +-
 scripts/livepatch/klp-build              | 250 ++++---
 tools/objtool/Build                      |   2 +-
 tools/objtool/Makefile                   |   4 +-
 tools/objtool/arch/x86/decode.c          |  17 +-
 tools/objtool/builtin-check.c            |  26 +-
 tools/objtool/builtin-klp.c              |   1 +
 tools/objtool/check.c                    | 412 ++++-------
 tools/objtool/disas.c                    |  22 +-
 tools/objtool/elf.c                      | 124 ++--
 tools/objtool/include/objtool/arch.h     |   3 +
 tools/objtool/include/objtool/builtin.h  |   7 +-
 tools/objtool/include/objtool/check.h    |  34 +-
 tools/objtool/include/objtool/checksum.h |  53 +-
 tools/objtool/include/objtool/elf.h      |  59 +-
 tools/objtool/include/objtool/klp.h      |   1 +
 tools/objtool/include/objtool/warn.h     |  57 +-
 tools/objtool/klp-checksum.c             | 347 ++++++++++
 tools/objtool/klp-diff.c                 | 826 ++++++++++++++++-------
 tools/objtool/objtool.c                  |   3 -
 tools/objtool/trace.c                    |   8 +-
 23 files changed, 1493 insertions(+), 776 deletions(-)
 create mode 100644 tools/objtool/klp-checksum.c

2.53.0