x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust

Add new ARCH_WARN_ASM macro for BUG/WARN assembly code sharing with
Rust to avoid the duplication.

No functional changes.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250502094537.231725-2-fujita.tomonori@gmail.com
[ Fixed typo in macro parameter name. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: fujita

arch/x86/include/asm/bug.h

@@ -32,45 +32,42 @@
 #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, line, 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
 
@@ -92,11 +89,14 @@ do {								\
  * were to trigger, we'd rather wreck the machine in an attempt to get the
  * message out than not know about it.
  */
+
+#define ARCH_WARN_REACHABLE	ANNOTATE_REACHABLE(1b)
+
 #define __WARN_FLAGS(flags)					\
 do {								\
 	__auto_type __flags = BUGFLAG_WARNING|(flags);		\
 	instrumentation_begin();				\
-	_BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE(1b));	\
+	_BUG_FLAGS(ASM_UD2, __flags, ARCH_WARN_REACHABLE);	\
 	instrumentation_end();					\
 } while (0)