kernel/tools/objtool, branch master

Merge tag 'objtool-urgent-2026-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-03-15T17:36:01Z

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

objtool: Fix another stack overflow in validate_branch()

2026-03-09T15:45:13Z

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: 70589843b36f ("objtool: Add option to trace function validation") Reported-by: Arnd Bergmann 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

objtool: Handle Clang RSP musical chairs

2026-03-09T15:45:10Z

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 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

objtool: Fix ERROR_INSN() error message

2026-03-06T15:53:37Z

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

objtool: Fix data alignment in elf_add_data()

2026-03-06T15:53:36Z

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: dd590d4d57eb ("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

objtool: Use HOSTCFLAGS for HAVE_XXHASH test

2026-03-06T15:48:41Z

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 | ^~~~~~~~~~ To resolve the error, we test HAVE_XXHASH by invoking HOSTCC with HOSTCFLAGS. Signed-off-by: HONG Yifan Reviewed-by: Carlos Llamas Link: https://patch.msgid.link/20260303010340.306164-1-elsk@google.com Signed-off-by: Josh Poimboeuf

objtool/klp: Avoid NULL pointer dereference when printing code symbol name

2026-03-06T15:47:11Z

Fix a hypothetical NULL pointer defereference of the 'code_sym' variable. In theory this should never happen. Reviewed-and-tested-by: Song Liu Link: https://patch.msgid.link/64116517bc93851a98fe366ea0a4d807f4c70aab.1770759954.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf

objtool/klp: Disable unsupported pr_debug() usage

2026-03-06T15:47:11Z

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 Link: https://patch.msgid.link/3a7db3a5b7d4abf9b2534803a74e2e7231322738.1770759954.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf

objtool/klp: Fix detection of corrupt static branch/call entries

2026-03-06T15:47:10Z

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: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files") Reported-by: Song Liu Reviewed-and-tested-by: Song Liu Link: https://patch.msgid.link/124ad747b751df0df1725eff89de8332e3fb26d6.1770759954.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf

kbuild: Leave objtool binary around with 'make clean'

2026-03-02T21:22:39Z

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 68b4fe32d737 ("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: 68b4fe32d737 ("kbuild: Add objtool to top-level clean target") Reported-by: Michal Suchanek Closes: https://lore.kernel.org/20260225112633.6123-1-msuchanek@suse.de/ Reported-by: Rainer Fiebig Closes: https://lore.kernel.org/62d12399-76e5-3d40-126a-7490b4795b17@mailbox.org/ Acked-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) Reviewed-by: Nicolas Schier Tested-by: Nicolas Schier Link: https://patch.msgid.link/20260227-avoid-objtool-binary-removal-clean-v1-1-122f3e55eae9@kernel.org Signed-off-by: Nathan Chancellor