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 jpoimboe@kernel.org Cc: Peter Zijlstra peterz@infradead.org Signed-off-by: Miguel Ojeda ojeda@kernel.org --- tools/objtool/check.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f23bdda737aa..3257eefc41ed 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -224,6 +224,7 @@ static bool is_rust_noreturn(const struct symbol *func) str_ends_with(func->name, "_4core9panicking14panic_explicit") || str_ends_with(func->name, "_4core9panicking14panic_nounwind") || str_ends_with(func->name, "_4core9panicking18panic_bounds_check") || + str_ends_with(func->name, "_4core9panicking18panic_nounwind_fmt") || str_ends_with(func->name, "_4core9panicking19assert_failed_inner") || str_ends_with(func->name, "_4core9panicking30panic_null_pointer_dereference") || str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") ||
On Sat, Jul 12, 2025 at 06:01:02PM +0200, Miguel Ojeda wrote:
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_fmtThus 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 jpoimboe@kernel.org Cc: Peter Zijlstra peterz@infradead.org Signed-off-by: Miguel Ojeda ojeda@kernel.org
Acked-by: Peter Zijlstra (Intel) peterz@infradead.org
tools/objtool/check.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f23bdda737aa..3257eefc41ed 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -224,6 +224,7 @@ static bool is_rust_noreturn(const struct symbol *func) str_ends_with(func->name, "_4core9panicking14panic_explicit") || str_ends_with(func->name, "_4core9panicking14panic_nounwind") || str_ends_with(func->name, "_4core9panicking18panic_bounds_check") ||
str_ends_with(func->name, "_4core9panicking18panic_nounwind_fmt") || str_ends_with(func->name, "_4core9panicking19assert_failed_inner") || str_ends_with(func->name, "_4core9panicking30panic_null_pointer_dereference") || str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") ||
Just having "_4core9panicking" substring is not sufficient?
On Mon, Jul 14, 2025 at 10:46 AM Peter Zijlstra peterz@infradead.org wrote:
On Sat, Jul 12, 2025 at 06:01:02PM +0200, Miguel Ojeda wrote:
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_fmtThus 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 jpoimboe@kernel.org Cc: Peter Zijlstra peterz@infradead.org Signed-off-by: Miguel Ojeda ojeda@kernel.org
Acked-by: Peter Zijlstra (Intel) peterz@infradead.org
tools/objtool/check.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f23bdda737aa..3257eefc41ed 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -224,6 +224,7 @@ static bool is_rust_noreturn(const struct symbol *func) str_ends_with(func->name, "_4core9panicking14panic_explicit") || str_ends_with(func->name, "_4core9panicking14panic_nounwind") || str_ends_with(func->name, "_4core9panicking18panic_bounds_check") ||
str_ends_with(func->name, "_4core9panicking18panic_nounwind_fmt") || str_ends_with(func->name, "_4core9panicking19assert_failed_inner") || str_ends_with(func->name, "_4core9panicking30panic_null_pointer_dereference") || str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") ||Just having "_4core9panicking" substring is not sufficient?
That prefix just means it is defined in the panicking.rs file, which also has a few functions that are not noreturn.
Alice
On Mon, Jul 14, 2025 at 10:48:33AM +0200, Alice Ryhl wrote:
tools/objtool/check.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f23bdda737aa..3257eefc41ed 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -224,6 +224,7 @@ static bool is_rust_noreturn(const struct symbol *func) str_ends_with(func->name, "_4core9panicking14panic_explicit") || str_ends_with(func->name, "_4core9panicking14panic_nounwind") || str_ends_with(func->name, "_4core9panicking18panic_bounds_check") ||
str_ends_with(func->name, "_4core9panicking18panic_nounwind_fmt") || str_ends_with(func->name, "_4core9panicking19assert_failed_inner") || str_ends_with(func->name, "_4core9panicking30panic_null_pointer_dereference") || str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") ||Just having "_4core9panicking" substring is not sufficient?
That prefix just means it is defined in the panicking.rs file, which also has a few functions that are not noreturn.
Oh well, I figured it was too good to be true anyway. Its just that there was a lot of that around and I had to ask :-)
linux-stable-mirror@lists.linaro.org
-
Alice Ryhl -
Miguel Ojeda -
Peter Zijlstra