x86/asm: Annotate special section entries

In preparation for the objtool klp diff subcommand, add annotations for
special section entries.  This will enable objtool to determine the size
and location of the entries and to extract them when needed.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

6 files changed, 15 insertions, 1 deletions

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 15bc07a5ebb3..b14c045679e1 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -198,6 +198,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
 
 #define ALTINSTR_ENTRY(ft_flags)					      \
 	".pushsection .altinstructions,\"a\"\n"				      \
+	ANNOTATE_DATA_SPECIAL						      \
 	" .long 771b - .\n"				/* label           */ \
 	" .long 774f - .\n"				/* new instruction */ \
 	" .4byte " __stringify(ft_flags) "\n"		/* feature + flags */ \
@@ -207,6 +208,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
 
 #define ALTINSTR_REPLACEMENT(newinstr)		/* replacement */	\
 	".pushsection .altinstr_replacement, \"ax\"\n"			\
+	ANNOTATE_DATA_SPECIAL						\
 	"# ALT: replacement\n"						\
 	"774:\n\t" newinstr "\n775:\n"					\
 	".popsection\n"
@@ -337,6 +339,7 @@ void nop_func(void);
  * instruction. See apply_alternatives().
  */
 .macro altinstr_entry orig alt ft_flags orig_len alt_len
+	ANNOTATE_DATA_SPECIAL
 	.long \orig - .
 	.long \alt - .
 	.4byte \ft_flags
@@ -365,6 +368,7 @@ void nop_func(void);
 	.popsection ;							\
 	.pushsection .altinstr_replacement,"ax"	;			\
 743:									\
+	ANNOTATE_DATA_SPECIAL ;						\
 	newinst	;							\
 744:									\
 	.popsection ;
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index d5c8d3afe196..bd62bd87a841 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_ASM_H
 #define _ASM_X86_ASM_H
 
+#include <linux/annotate.h>
+
 #ifdef __ASSEMBLER__
 # define __ASM_FORM(x, ...)		x,## __VA_ARGS__
 # define __ASM_FORM_RAW(x, ...)		x,## __VA_ARGS__
@@ -132,6 +134,7 @@ static __always_inline __pure void *rip_rel_ptr(void *p)
 # define _ASM_EXTABLE_TYPE(from, to, type)			\
 	.pushsection "__ex_table","a" ;				\
 	.balign 4 ;						\
+	ANNOTATE_DATA_SPECIAL ;					\
 	.long (from) - . ;					\
 	.long (to) - . ;					\
 	.long type ;						\
@@ -179,6 +182,7 @@ static __always_inline __pure void *rip_rel_ptr(void *p)
 # define _ASM_EXTABLE_TYPE(from, to, type)			\
 	" .pushsection \"__ex_table\",\"a\"\n"			\
 	" .balign 4\n"						\
+	ANNOTATE_DATA_SPECIAL					\
 	" .long (" #from ") - .\n"				\
 	" .long (" #to ") - .\n"				\
 	" .long " __stringify(type) " \n"			\
@@ -187,6 +191,7 @@ static __always_inline __pure void *rip_rel_ptr(void *p)
 # define _ASM_EXTABLE_TYPE_REG(from, to, type, reg)				\
 	" .pushsection \"__ex_table\",\"a\"\n"					\
 	" .balign 4\n"								\
+	ANNOTATE_DATA_SPECIAL							\
 	" .long (" #from ") - .\n"						\
 	" .long (" #to ") - .\n"						\
 	DEFINE_EXTABLE_TYPE_REG							\
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 880ca15073ed..372f4018880c 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -57,6 +57,7 @@
 #define _BUG_FLAGS_ASM(ins, file, line, flags, size, extra)		\
 	"1:\t" ins "\n"							\
 	".pushsection __bug_table,\"aw\"\n"				\
+	ANNOTATE_DATA_SPECIAL						\
 	__BUG_ENTRY(file, line, flags)					\
 	"\t.org 2b + " size "\n"					\
 	".popsection\n"							\
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 893cbca37fe9..fc5f32d4da6e 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -101,6 +101,7 @@ static __always_inline bool _static_cpu_has(u16 bit)
 	asm goto(ALTERNATIVE_TERNARY("jmp 6f", %c[feature], "", "jmp %l[t_no]")
 		".pushsection .altinstr_aux,\"ax\"\n"
 		"6:\n"
+		ANNOTATE_DATA_SPECIAL
 		" testb %[bitnum], %a[cap_byte]\n"
 		" jnz %l[t_yes]\n"
 		" jmp %l[t_no]\n"
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
index 61dd1dee7812..e0a6930a4029 100644
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -15,6 +15,7 @@
 #define JUMP_TABLE_ENTRY(key, label)			\
 	".pushsection __jump_table,  \"aw\" \n\t"	\
 	_ASM_ALIGN "\n\t"				\
+	ANNOTATE_DATA_SPECIAL				\
 	".long 1b - . \n\t"				\
 	".long " label " - . \n\t"			\
 	_ASM_PTR " " key " - . \n\t"			\
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 1973e9f14bf9..4fea6a042b28 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -9,9 +9,10 @@
 
 #ifndef __ASSEMBLY__
 
-#define UNWIND_HINT(type, sp_reg, sp_offset, signal)	\
+#define UNWIND_HINT(type, sp_reg, sp_offset, signal)		\
 	"987: \n\t"						\
 	".pushsection .discard.unwind_hints\n\t"		\
+	ANNOTATE_DATA_SPECIAL					\
 	/* struct unwind_hint */				\
 	".long 987b - .\n\t"					\
 	".short " __stringify(sp_offset) "\n\t"			\
@@ -78,6 +79,7 @@
 .macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
 .Lhere_\@:
 	.pushsection .discard.unwind_hints
+		ANNOTATE_DATA_SPECIAL
 		/* struct unwind_hint */
 		.long .Lhere_\@ - .
 		.short \sp_offset