Re: [PATCH] objtool/rust: add one more `noreturn` Rust function

[Gary Guo]

On Sun, 12 Jan 2025 15:39:51 +0100
Miguel Ojeda <ojeda@xxxxxxxxxx> wrote:

> Starting with Rust 1.85.0 (currently in beta, to be released 2025-02-20),
> under some kernel configurations with `CONFIG_RUST_DEBUG_ASSERTIONS=y`,
> one may trigger a new `objtool` warning:
> 
>     rust/kernel.o: warning: objtool: _R...securityNtB2_11SecurityCtx8as_bytes()
>     falls through to next function _R...core3ops4drop4Drop4drop()
> 
> due to a call to the `noreturn` symbol:
> 
>     core::panicking::assert_failed::<usize, usize>
> 
> Thus add it to the list so that `objtool` knows it is actually `noreturn`.
> Do so matching with `strstr` since it is a generic.
> 
> See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions")
> for more details.
> 
> Cc: <stable@xxxxxxxxxxxxxxx> # Needed in 6.12.y only (Rust is pinned in older LTSs).
> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>

Reviewed-by: Gary Guo <gary@xxxxxxxxxxx>

> ---
>  tools/objtool/check.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 76060da755b5..e7ec29dfdff2 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -218,6 +218,7 @@ static bool is_rust_noreturn(const struct symbol *func)
>  	       str_ends_with(func->name, "_4core9panicking18panic_bounds_check")			||
>  	       str_ends_with(func->name, "_4core9panicking19assert_failed_inner")			||
>  	       str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference")	||
> +	       strstr(func->name, "_4core9panicking13assert_failed")					||
>  	       strstr(func->name, "_4core9panicking11panic_const24panic_const_")			||
>  	       (strstr(func->name, "_4core5slice5index24slice_") &&
>  		str_ends_with(func->name, "_fail"));
> 
> base-commit: 9d89551994a430b50c4fffcb1e617a057fa76e20