en Copyright 2015 Java http://kernelsources.org:8080/source/history/linux/tools/objtool/tests/generic/test-checksum-insn.sh#5b6dca02b3e2254d2fd5706d76d7ab4610a67296 Merge tag 'objtool-core-2026-10-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipPull objtool updates from Ingo Molnar: - Add unit test suite for objtool klp functionality and known failure modes (by Song Liu and Puranjay Mohan, with fixes by Joe Lawrence)* tag 'objtool-core-2026-10-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) objtool/klp: Add test for ThinLTO symbols sharing a demangled name objtool/klp: Add test for Clang switch jump tables objtool/klp: Add test for UBSAN metadata in an unchanged function objtool/klp: Add test for absolute and __ADDRESSABLE symbols objtool/klp: Add test for a patch which strips a data annotation objtool/klp: Add test for the alignment of cloned data sections objtool/klp: Add test for alternative replacement code in checksums objtool/klp: Add test for instruction operand checksums objtool/klp: Add test for a static call introduced by the patch objtool/klp: Add test for tracepoint and pr_debug static branch keys objtool/klp: Add test for a static branch introduced by the patch objtool/klp: Add test for symbols with no checksum entry of their own objtool/klp: Add test for data object checksums objtool/klp: Test text annotations on alternative replacements objtool/klp: Test a hand-built livepatch module's static call keys objtool/klp: Test rejection of a file-local static branch key objtool/klp: Add test for symbols whose linkage the patch changes objtool/klp: Add test for kCFI prefix symbols and traps objtool/klp: Add test for __bug_table, __ex_table and __mcount_loc extraction objtool/klp: Add test for static locals which must not be correlated ... List of files: /linux/tools/objtool/tests/generic/test-checksum-insn.sh Wed, 21 Oct 2026 00:55:04 +0200 Linus Torvalds <torvalds@linux-foundation.org> http://kernelsources.org:8080/source/history/linux/tools/objtool/tests/generic/test-checksum-insn.sh#065f09c8332f9d5cf6ee5cd2494b9af179ee749b objtool/klp: Add test for instruction operand checksumschecksum_update_insn() hashes an instruction's bytes and then what anyrelocation on it refers to: a string section contributes the string'scontents, anything else the target symbol's name and adjusted addend, witha reference to a static resolved through its section symbol first.None of that shows up in the bytes. A rel32 operand is zero in the objectand supplied by the relocation, so calling a different function, editing aliteral the code passes, or reading a different index of an array all leavethe encoded instruction byte-identical. A checksum stopping at the bytesreports the function unchanged and the patch silently does not contain thefix.test-checksum-position is the other half: what must *not* change thechecksum when a function merely moves.Each of the four is verified by sabotaging the line it covers. The staticcase needed a writer the compiler cannot see through -- without one itproves the array is never written, folds every read to zero, and emits norelocation at all, so the reference under test does not exist and thevariant passes having compared two identical objects.Assisted-by: Claude:claude-opus-4Based-on-test-by: Joe Lawrence <joe.lawrence@redhat.com>Assisted-by: Claude:claude-opus-5Signed-off-by: Song Liu <song@kernel.org>Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>Signed-off-by: Ingo Molnar <mingo@kernel.org>Link: https://patch.msgid.link/20260916184351.2720310-52-song@kernel.org List of files: /linux/tools/objtool/tests/generic/test-checksum-insn.sh Wed, 16 Sep 2026 20:43:44 +0200 Song Liu <song@kernel.org>