linux/tools/objtool/check.c, branch v6.16

Merge tag 'rust-fixes-6.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2025-07-19T16:22:26Z

Pull Rust fixes from Miguel Ojeda: "Toolchain and infrastructure: - Fix build and modpost confusion for the upcoming Rust 1.89.0 release - Clean objtool warning for the upcoming Rust 1.89.0 release by adding one more noreturn function 'kernel' crate: - Fix build error when using generics in the 'try_{,pin_}init!' macros" * tag 'rust-fixes-6.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: rust: use `#[used(compiler)]` to fix build and `modpost` with Rust >= 1.89.0 objtool/rust: add one more `noreturn` Rust function for Rust 1.89.0 rust: init: Fix generics in *_init! macros

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

2025-07-14T21:09:02Z

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

objtool: Add missing endian conversion to read_annotate()

2025-07-01T13:02:04Z

Trying to compile an x86 kernel on big endian results in this error: net/ipv4/netfilter/iptable_nat.o: warning: objtool: iptable_nat_table_init+0x150: Unknown annotation type: 50331648 make[5]: *** [scripts/Makefile.build:287: net/ipv4/netfilter/iptable_nat.o] Error 255 Reason is a missing endian conversion in read_annotate(). Add the missing conversion to fix this. Fixes: 2116b349e29a ("objtool: Generic annotation infrastructure") Signed-off-by: Heiko Carstens Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250630131230.4130185-1-hca@linux.ibm.com

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

2025-05-22T10:00:58Z

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

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

2025-05-06T22:08:51Z

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

Merge tag 'rust-fixes-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2025-04-19T17:02:43Z

Pull rust fixes from Miguel Ojeda: "Toolchain and infrastructure: - Fix missing KASAN LLVM flags on first build (and fix spurious rebuilds) by skipping '--target' - Fix Make < 4.3 build error by using '$(pound)' - Fix UML build error by removing 'volatile' qualifier from io helpers - Fix UML build error by adding 'dma_{alloc,free}_attrs()' helpers - Clean gendwarfksyms warnings by avoiding to export '__pfx' symbols - Clean objtool warning by adding a new 'noreturn' function for 1.86.0 - Disable 'needless_continue' Clippy lint due to new 1.86.0 warnings - Add missing 'ffi' crate to 'generate_rust_analyzer.py' 'pin-init' crate: - Import a couple fixes from upstream" * tag 'rust-fixes-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: rust: helpers: Add dma_alloc_attrs() and dma_free_attrs() rust: helpers: Remove volatile qualifier from io helpers rust: kbuild: use `pound` to support GNU Make < 4.3 objtool/rust: add one more `noreturn` Rust function for Rust 1.86.0 rust: kasan/kbuild: fix missing flags on first build rust: disable `clippy::needless_continue` rust: kbuild: Don't export __pfx symbols rust: pin-init: use Markdown autolinks in Rust comments rust: pin-init: alloc: restrict `impl ZeroableOption` for `Box` to `T: Sized` scripts: generate_rust_analyzer: Add ffi crate

objtool/rust: add one more `noreturn` Rust function for Rust 1.86.0

2025-04-14T15:02:49Z

Starting with Rust 1.86.0 (see upstream commit b151b513ba2b ("Insert null checks for pointer dereferences when debug assertions are enabled") [1]), under some kernel configurations with `CONFIG_RUST_DEBUG_ASSERTIONS=y`, one may trigger a new `objtool` warning: rust/kernel.o: warning: objtool: _R..._6kernel9workqueue6system() falls through to next function _R...9workqueue14system_highpri() due to a call to the `noreturn` symbol: core::panicking::panic_null_pointer_dereference Thus add it 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). Fixes: 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") Link: https://github.com/rust-lang/rust/commit/b151b513ba2b65c7506ec1a80f2712bbd09154d1 [1] Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250413002338.1741593-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda

objtool: Remove ANNOTATE_IGNORE_ALTERNATIVE from CLAC/STAC

2025-04-08T20:03:51Z

ANNOTATE_IGNORE_ALTERNATIVE adds additional noise to the code generated by CLAC/STAC alternatives, hurting readability for those whose read uaccess-related code generation on a regular basis. Remove the annotation specifically for the "NOP patched with CLAC/STAC" case in favor of a manual check. Leave the other uses of that annotation in place as they're less common and more difficult to detect. Suggested-by: Linus Torvalds Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Acked-by: Linus Torvalds Link: https://lore.kernel.org/r/fc972ba4995d826fcfb8d02733a14be8d670900b.1744098446.git.jpoimboe@kernel.org

objtool, xen: Fix INSN_SYSCALL / INSN_SYSRET semantics

2025-04-08T07:14:12Z

Objtool uses an arbitrary rule for INSN_SYSCALL and INSN_SYSRET that almost works by accident: if it's in a function, control flow continues after the instruction, otherwise it terminates. That behavior should instead be based on the semantics of the underlying instruction. Change INSN_SYSCALL to always preserve control flow and INSN_SYSRET to always terminate it. The changed semantic for INSN_SYSCALL requires a tweak to the !CONFIG_IA32_EMULATION version of xen_entry_SYSCALL_compat(). In Xen, SYSCALL is a hypercall which usually returns. But in this case it's a hypercall to IRET which doesn't return. Add UD2 to tell objtool to terminate control flow, and to prevent undefined behavior at runtime. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Reviewed-by: Juergen Gross # for the Xen part Cc: Linus Torvalds Link: https://lore.kernel.org/r/19453dfe9a0431b7f016e9dc16d031cad3812a50.1744095216.git.jpoimboe@kernel.org

objtool: Stop UNRET validation on UD2

2025-04-08T07:14:11Z

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