kernel/linux.git/tools/objtool/check.c, branch v6.12.80

objtool: Handle Clang RSP musical chairs

2026-04-02T11:09:29+00:00

[ Upstream commit 7fdaa640c810cb42090a182c33f905bcc47a616a ] 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 Signed-off-by: Sasha Levin

objtool: Fix standalone --hacks=jump_label

2025-12-18T12:54:41+00:00

[ Upstream commit be8374a5ba7cbab6b97df94b4ffe0b92f5c8a6d2 ] The objtool command line 'objtool --hacks=jump_label foo.o' on its own should be expected to rewrite jump labels to NOPs. This means the add_special_section_alts() code path needs to run when only this option is provided. This is mainly relevant in certain debugging situations, but could potentially also fix kernel builds in which objtool is run with --hacks=jump_label but without --orc, --stackval, --uaccess, or --hacks=noinstr. Fixes: de6fbcedf5ab ("objtool: Read special sections with alts only when specific options are selected") Signed-off-by: Dylan Hatch Signed-off-by: Josh Poimboeuf Signed-off-by: Sasha Levin

objtool/rust: add one more `noreturn` Rust function

2025-10-29T13:09:01+00:00

commit dbdf2a7feb422f9bacfd12774e624cf26f503eb0 upstream. Between Rust 1.79 and 1.86, under `CONFIG_RUST_KERNEL_DOCTESTS=y`, `objtool` may report: rust/doctests_kernel_generated.o: warning: objtool: rust_doctest_kernel_alloc_kbox_rs_13() falls through to next function rust_doctest_kernel_alloc_kvec_rs_0() (as well as in rust_doctest_kernel_alloc_kvec_rs_0) due to calls to the `noreturn` symbol: core::option::expect_failed from code added in commits 779db37373a3 ("rust: alloc: kvec: implement AsPageIter for VVec") and 671618432f46 ("rust: alloc: kbox: implement AsPageIter for VBox"). Thus add the mangled one to the list so that `objtool` knows it is actually `noreturn`. This can be reproduced as well in other versions by tweaking the code, such as the latest stable Rust (1.90.0). Stable does not have code that triggers this, but it could have it in the future. Downstream forks could too. Thus tag it for backport. See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") for more details. Signed-off-by: Miguel Ojeda Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alice Ryhl Cc: stable@vger.kernel.org # Needed in 6.12.y and later. Link: https://patch.msgid.link/20251020020714.2511718-1-ojeda@kernel.org Signed-off-by: Greg Kroah-Hartman

objtool/rust: add one more `noreturn` Rust function for Rust 1.89.0

2025-07-24T06:56:22+00:00

commit aa7b65c2a29e8b07057b13624102c6810597c0d5 upstream. Starting with Rust 1.89.0 (expected 2025-08-07), under `CONFIG_RUST_DEBUG_ASSERTIONS=y`, `objtool` may report: rust/kernel.o: warning: objtool: _R..._6kernel4pageNtB5_4Page8read_raw() falls through to next function _R..._6kernel4pageNtB5_4Page9write_raw() (and many others) due to calls to the `noreturn` symbol: core::panicking::panic_nounwind_fmt Thus add the mangled one to the list so that `objtool` knows it is actually `noreturn`. See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") for more details. Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Cc: Josh Poimboeuf Cc: Peter Zijlstra Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250712160103.1244945-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

objtool/rust: relax slice condition to cover more `noreturn` Rust functions

2025-06-19T13:32:33+00:00

commit cbeaa41dfe26b72639141e87183cb23e00d4b0dd upstream. Developers are indeed hitting other of the `noreturn` slice symbols in Nova [1], thus relax the last check in the list so that we catch all of them, i.e. *_4core5slice5index22slice_index_order_fail *_4core5slice5index24slice_end_index_len_fail *_4core5slice5index26slice_start_index_len_fail *_4core5slice5index29slice_end_index_overflow_fail *_4core5slice5index31slice_start_index_overflow_fail These all exist since at least Rust 1.78.0, thus backport it too. See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") for more details. Cc: stable@vger.kernel.org # Needed in 6.12.y and later. Cc: John Hubbard Cc: Timur Tabi Cc: Kane York Cc: Josh Poimboeuf Cc: Peter Zijlstra Reported-by: Joel Fernandes Fixes: 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") Closes: https://lore.kernel.org/rust-for-linux/20250513180757.GA1295002@joelnvbox/ [1] Tested-by: Joel Fernandes Link: https://lore.kernel.org/r/20250520185555.825242-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

objtool: Fix error handling inconsistencies in check()

2025-05-29T09:02:16+00:00

[ Upstream commit b745962cb97569aad026806bb0740663cf813147 ] Make sure all fatal errors are funneled through the 'out' label with a negative ret. Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Brendan Jackman Link: https://lore.kernel.org/r/0f49d6a27a080b4012e84e6df1e23097f44cc082.1741975349.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin

objtool: Properly disable uaccess validation

2025-05-29T09:02:08+00:00

[ Upstream commit e1a9dda74dbffbc3fa2069ff418a1876dc99fb14 ] If opts.uaccess isn't set, the uaccess validation is disabled, but only partially: it doesn't read the uaccess_safe_builtin list but still tries to do the validation. Disable it completely to prevent false warnings. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/0e95581c1d2107fb5f59418edf2b26bba38b0cbb.1742852846.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin

objtool/rust: add one more `noreturn` Rust function for Rust 1.87.0

2025-05-18T06:24:51+00:00

commit 19f5ca461d5fc09bdf93a9f8e4bd78ed3a49dc71 upstream. Starting with Rust 1.87.0 (expected 2025-05-15), `objtool` may report: rust/core.o: warning: objtool: _R..._4core9panicking9panic_fmt() falls through to next function _R..._4core9panicking18panic_nounwind_fmt() rust/core.o: warning: objtool: _R..._4core9panicking18panic_nounwind_fmt() falls through to next function _R..._4core9panicking5panic() The reason is that `rust_begin_unwind` is now mangled: _R..._7___rustc17rust_begin_unwind Thus add the mangled one to the list so that `objtool` knows it is actually `noreturn`. See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") for more details. Alternatively, we could remove the fixed one in `noreturn.h` and relax this test to cover both, but it seems best to be strict as long as we can. Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Cc: Josh Poimboeuf Cc: Peter Zijlstra Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250502140237.1659624-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

objtool: Ignore end-of-section jumps for KCOV/GCOV

2025-05-02T05:59:33+00:00

commit 0d7597749f5a3ac67851d3836635d084df15fb66 upstream. When KCOV or GCOV is enabled, dead code can be left behind, in which case objtool silences unreachable and undefined behavior (fallthrough) warnings. Fallthrough warnings, and their variant "end of section" warnings, were silenced with the following commit: 6b023c784204 ("objtool: Silence more KCOV warnings") Another variant of a fallthrough warning is a jump to the end of a function. If that function happens to be at the end of a section, the jump destination doesn't actually exist. Normally that would be a fatal objtool error, but for KCOV/GCOV it's just another undefined behavior fallthrough. Silence it like the others. Fixes the following warning: drivers/iommu/dma-iommu.o: warning: objtool: iommu_dma_sw_msi+0x92: can't find jump dest instruction at .text+0x54d5 Fixes: 6b023c784204 ("objtool: Silence more KCOV warnings") Reported-by: Randy Dunlap Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/08fbe7d7e1e20612206f1df253077b94f178d93e.1743481539.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/314f8809-cd59-479b-97d7-49356bf1c8d1@infradead.org/ Signed-off-by: Greg Kroah-Hartman

objtool: Stop UNRET validation on UD2

2025-05-02T05:59:23+00:00

[ Upstream commit 9f9cc012c2cbac4833746a0182e06a8eec940d19 ] In preparation for simplifying INSN_SYSCALL, make validate_unret() terminate control flow on UD2 just like validate_branch() already does. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/ce841269e7e28c8b7f32064464a9821034d724ff.1744095216.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin