[PATCH v2 1/5] x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust

[Peter Zijlstra]

On Wed, Dec 18, 2024 at 03:20:05PM +0900, FUJITA Tomonori wrote:
> Add new ARCH_WARN_ASM macro for BUG/WARN assembly code sharing with
> Rust to avoid the duplication.

This conflicts with some patches I've been sitting on, but nothing that
I can't resolve I think.

Acked-by: Peter Zijlstra (Intel) <peterz at infradead.org>

> Signed-off-by: FUJITA Tomonori <fujita.tomonori at gmail.com>
> ---
>  arch/x86/include/asm/bug.h | 51 ++++++++++++++++++--------------------
>  1 file changed, 24 insertions(+), 27 deletions(-)
> 
> diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
> index 806649c7f23d..71df68e2a731 100644
> --- a/arch/x86/include/asm/bug.h
> +++ b/arch/x86/include/asm/bug.h
> @@ -28,45 +28,42 @@
>  #ifdef CONFIG_GENERIC_BUG
>  
>  #ifdef CONFIG_X86_32
> -# define __BUG_REL(val)	".long " __stringify(val)
> +# define __BUG_REL(val)	".long " val
>  #else
> -# define __BUG_REL(val)	".long " __stringify(val) " - ."
> +# define __BUG_REL(val)	".long " val " - ."
>  #endif
>  
>  #ifdef CONFIG_DEBUG_BUGVERBOSE
> +#define __BUG_ENTRY(file, line, flags)					\
> +	"2:\t" __BUG_REL("1b") "\t# bug_entry::bug_addr\n"		\
> +	"\t" __BUG_REL(file)   "\t# bug_entry::file\n"			\
> +	"\t.word " line        "\t# bug_entry::line\n"			\
> +	"\t.word " flags       "\t# bug_entry::flags\n"
> +#else
> +#define __BUG_ENTRY(file, ine, flags)					\
> +	"2:\t" __BUG_REL("1b") "\t# bug_entry::bug_addr\n"		\
> +	"\t.word " flags       "\t# bug_entry::flags\n"
> +#endif
> +
> +#define _BUG_FLAGS_ASM(ins, file, line, flags, size, extra)		\
> +	"1:\t" ins "\n"							\
> +	".pushsection __bug_table,\"aw\"\n"				\
> +	__BUG_ENTRY(file, line, flags)					\
> +	"\t.org 2b + " size "\n"					\
> +	".popsection\n"							\
> +	extra
>  
>  #define _BUG_FLAGS(ins, flags, extra)					\
>  do {									\
> -	asm_inline volatile("1:\t" ins "\n"				\
> -		     ".pushsection __bug_table,\"aw\"\n"		\
> -		     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"	\
> -		     "\t"  __BUG_REL(%c0) "\t# bug_entry::file\n"	\
> -		     "\t.word %c1"        "\t# bug_entry::line\n"	\
> -		     "\t.word %c2"        "\t# bug_entry::flags\n"	\
> -		     "\t.org 2b+%c3\n"					\
> -		     ".popsection\n"					\
> -		     extra						\
> +	asm_inline volatile(_BUG_FLAGS_ASM(ins, "%c0",			\
> +					   "%c1", "%c2", "%c3", extra)	\
>  		     : : "i" (__FILE__), "i" (__LINE__),		\
>  			 "i" (flags),					\
>  			 "i" (sizeof(struct bug_entry)));		\
>  } while (0)
>  
> -#else /* !CONFIG_DEBUG_BUGVERBOSE */
> -
> -#define _BUG_FLAGS(ins, flags, extra)					\
> -do {									\
> -	asm_inline volatile("1:\t" ins "\n"				\
> -		     ".pushsection __bug_table,\"aw\"\n"		\
> -		     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"	\
> -		     "\t.word %c0"        "\t# bug_entry::flags\n"	\
> -		     "\t.org 2b+%c1\n"					\
> -		     ".popsection\n"					\
> -		     extra						\
> -		     : : "i" (flags),					\
> -			 "i" (sizeof(struct bug_entry)));		\
> -} while (0)
> -
> -#endif /* CONFIG_DEBUG_BUGVERBOSE */
> +#define ARCH_WARN_ASM(file, line, flags, size)				\
> +	_BUG_FLAGS_ASM(ASM_UD2, file, line, flags, size, "")
>  
>  #else
>  
> -- 
> 2.43.0
> 
>