From d2c60bde1c0fcac8b140e527546f80749ccd9c67 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Sep 2025 09:03:53 -0700 Subject: objtool: Move ANNOTATE* macros to annotate.h In preparation for using the objtool annotation macros in higher-level objtool.h macros like UNWIND_HINT, move them to their own file. Acked-by: Petr Mladek Tested-by: Joe Lawrence Signed-off-by: Josh Poimboeuf --- include/linux/annotate.h | 109 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 include/linux/annotate.h (limited to 'include/linux/annotate.h') diff --git a/include/linux/annotate.h b/include/linux/annotate.h new file mode 100644 index 000000000000..ccb445496331 --- /dev/null +++ b/include/linux/annotate.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_ANNOTATE_H +#define _LINUX_ANNOTATE_H + +#include + +#ifdef CONFIG_OBJTOOL + +#ifndef __ASSEMBLY__ + +#define __ASM_ANNOTATE(label, type) \ + ".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t" \ + ".long " __stringify(label) " - .\n\t" \ + ".long " __stringify(type) "\n\t" \ + ".popsection\n\t" + +#define ASM_ANNOTATE(type) \ + "911:\n\t" \ + __ASM_ANNOTATE(911b, type) + +#else /* __ASSEMBLY__ */ + +.macro ANNOTATE type:req +.Lhere_\@: + .pushsection .discard.annotate_insn,"M",@progbits,8 + .long .Lhere_\@ - . + .long \type + .popsection +.endm + +#endif /* __ASSEMBLY__ */ + +#else /* !CONFIG_OBJTOOL */ +#ifndef __ASSEMBLY__ +#define __ASM_ANNOTATE(label, type) "" +#define ASM_ANNOTATE(type) +#else /* __ASSEMBLY__ */ +.macro ANNOTATE type:req +.endm +#endif /* __ASSEMBLY__ */ +#endif /* !CONFIG_OBJTOOL */ + +#ifndef __ASSEMBLY__ + +/* + * Annotate away the various 'relocation to !ENDBR` complaints; knowing that + * these relocations will never be used for indirect calls. + */ +#define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR) +#define ANNOTATE_NOENDBR_SYM(sym) asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOENDBR)) + +/* + * This should be used immediately before an indirect jump/call. It tells + * objtool the subsequent indirect jump/call is vouched safe for retpoline + * builds. + */ +#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE) +/* + * See linux/instrumentation.h + */ +#define ANNOTATE_INSTR_BEGIN(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_BEGIN) +#define ANNOTATE_INSTR_END(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_END) +/* + * objtool annotation to ignore the alternatives and only consider the original + * instruction(s). + */ +#define ANNOTATE_IGNORE_ALTERNATIVE ASM_ANNOTATE(ANNOTYPE_IGNORE_ALTS) +/* + * This macro indicates that the following intra-function call is valid. + * Any non-annotated intra-function call will cause objtool to issue a warning. + */ +#define ANNOTATE_INTRA_FUNCTION_CALL ASM_ANNOTATE(ANNOTYPE_INTRA_FUNCTION_CALL) +/* + * Use objtool to validate the entry requirement that all code paths do + * VALIDATE_UNRET_END before RET. + * + * NOTE: The macro must be used at the beginning of a global symbol, otherwise + * it will be ignored. + */ +#define ANNOTATE_UNRET_BEGIN ASM_ANNOTATE(ANNOTYPE_UNRET_BEGIN) +/* + * This should be used to refer to an instruction that is considered + * terminating, like a noreturn CALL or UD2 when we know they are not -- eg + * WARN using UD2. + */ +#define ANNOTATE_REACHABLE(label) __ASM_ANNOTATE(label, ANNOTYPE_REACHABLE) +/* + * This should not be used; it annotates away CFI violations. There are a few + * valid use cases like kexec handover to the next kernel image, and there is + * no security concern there. + * + * There are also a few real issues annotated away, like EFI because we can't + * control the EFI code. + */ +#define ANNOTATE_NOCFI_SYM(sym) asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOCFI)) + +#else /* __ASSEMBLY__ */ +#define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR +#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE +/* ANNOTATE_INSTR_BEGIN ANNOTATE type=ANNOTYPE_INSTR_BEGIN */ +/* ANNOTATE_INSTR_END ANNOTATE type=ANNOTYPE_INSTR_END */ +#define ANNOTATE_IGNORE_ALTERNATIVE ANNOTATE type=ANNOTYPE_IGNORE_ALTS +#define ANNOTATE_INTRA_FUNCTION_CALL ANNOTATE type=ANNOTYPE_INTRA_FUNCTION_CALL +#define ANNOTATE_UNRET_BEGIN ANNOTATE type=ANNOTYPE_UNRET_BEGIN +#define ANNOTATE_REACHABLE ANNOTATE type=ANNOTYPE_REACHABLE +#define ANNOTATE_NOCFI_SYM ANNOTATE type=ANNOTYPE_NOCFI +#endif /* __ASSEMBLY__ */ + +#endif /* _LINUX_ANNOTATE_H */ -- cgit v1.2.3 From 58f36a5756445dcd0a733504cd798955ebe968c1 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Sep 2025 09:03:54 -0700 Subject: objtool: Add ANNOTATE_DATA_SPECIAL In preparation for the objtool klp diff subcommand, add an ANNOTATE_DATA_SPECIAL macro which annotates special section entries so that objtool can determine their size and location and extract them when needed. Acked-by: Petr Mladek Tested-by: Joe Lawrence Signed-off-by: Josh Poimboeuf --- include/linux/annotate.h | 49 ++++++++++++++++++++++++++++++++++++------------ 1 file changed, 37 insertions(+), 12 deletions(-) (limited to 'include/linux/annotate.h') diff --git a/include/linux/annotate.h b/include/linux/annotate.h index ccb445496331..7c10d34d198c 100644 --- a/include/linux/annotate.h +++ b/include/linux/annotate.h @@ -8,34 +8,52 @@ #ifndef __ASSEMBLY__ -#define __ASM_ANNOTATE(label, type) \ - ".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t" \ +#define __ASM_ANNOTATE(section, label, type) \ + ".pushsection " section ",\"M\", @progbits, 8\n\t" \ ".long " __stringify(label) " - .\n\t" \ ".long " __stringify(type) "\n\t" \ ".popsection\n\t" +#define ASM_ANNOTATE_LABEL(label, type) \ + __ASM_ANNOTATE(".discard.annotate_insn", label, type) + #define ASM_ANNOTATE(type) \ "911:\n\t" \ - __ASM_ANNOTATE(911b, type) + ASM_ANNOTATE_LABEL(911b, type) + +#define ASM_ANNOTATE_DATA(type) \ + "912:\n\t" \ + __ASM_ANNOTATE(".discard.annotate_data", 912b, type) #else /* __ASSEMBLY__ */ -.macro ANNOTATE type:req +.macro __ANNOTATE section, type .Lhere_\@: - .pushsection .discard.annotate_insn,"M",@progbits,8 + .pushsection \section, "M", @progbits, 8 .long .Lhere_\@ - . .long \type .popsection .endm +.macro ANNOTATE type + __ANNOTATE ".discard.annotate_insn", \type +.endm + +.macro ANNOTATE_DATA type + __ANNOTATE ".discard.annotate_data", \type +.endm + #endif /* __ASSEMBLY__ */ #else /* !CONFIG_OBJTOOL */ #ifndef __ASSEMBLY__ -#define __ASM_ANNOTATE(label, type) "" +#define ASM_ANNOTATE_LABEL(label, type) "" #define ASM_ANNOTATE(type) +#define ASM_ANNOTATE_DATA(type) #else /* __ASSEMBLY__ */ -.macro ANNOTATE type:req +.macro ANNOTATE type +.endm +.macro ANNOTATE_DATA type .endm #endif /* __ASSEMBLY__ */ #endif /* !CONFIG_OBJTOOL */ @@ -47,7 +65,7 @@ * these relocations will never be used for indirect calls. */ #define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR) -#define ANNOTATE_NOENDBR_SYM(sym) asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOENDBR)) +#define ANNOTATE_NOENDBR_SYM(sym) asm(ASM_ANNOTATE_LABEL(sym, ANNOTYPE_NOENDBR)) /* * This should be used immediately before an indirect jump/call. It tells @@ -58,8 +76,8 @@ /* * See linux/instrumentation.h */ -#define ANNOTATE_INSTR_BEGIN(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_BEGIN) -#define ANNOTATE_INSTR_END(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_END) +#define ANNOTATE_INSTR_BEGIN(label) ASM_ANNOTATE_LABEL(label, ANNOTYPE_INSTR_BEGIN) +#define ANNOTATE_INSTR_END(label) ASM_ANNOTATE_LABEL(label, ANNOTYPE_INSTR_END) /* * objtool annotation to ignore the alternatives and only consider the original * instruction(s). @@ -83,7 +101,7 @@ * terminating, like a noreturn CALL or UD2 when we know they are not -- eg * WARN using UD2. */ -#define ANNOTATE_REACHABLE(label) __ASM_ANNOTATE(label, ANNOTYPE_REACHABLE) +#define ANNOTATE_REACHABLE(label) ASM_ANNOTATE_LABEL(label, ANNOTYPE_REACHABLE) /* * This should not be used; it annotates away CFI violations. There are a few * valid use cases like kexec handover to the next kernel image, and there is @@ -92,7 +110,13 @@ * There are also a few real issues annotated away, like EFI because we can't * control the EFI code. */ -#define ANNOTATE_NOCFI_SYM(sym) asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOCFI)) +#define ANNOTATE_NOCFI_SYM(sym) asm(ASM_ANNOTATE_LABEL(sym, ANNOTYPE_NOCFI)) + +/* + * Annotate a special section entry. This emables livepatch module generation + * to find and extract individual special section entries as needed. + */ +#define ANNOTATE_DATA_SPECIAL ASM_ANNOTATE_DATA(ANNOTYPE_DATA_SPECIAL) #else /* __ASSEMBLY__ */ #define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR @@ -104,6 +128,7 @@ #define ANNOTATE_UNRET_BEGIN ANNOTATE type=ANNOTYPE_UNRET_BEGIN #define ANNOTATE_REACHABLE ANNOTATE type=ANNOTYPE_REACHABLE #define ANNOTATE_NOCFI_SYM ANNOTATE type=ANNOTYPE_NOCFI +#define ANNOTATE_DATA_SPECIAL ANNOTATE_DATA type=ANNOTYPE_DATA_SPECIAL #endif /* __ASSEMBLY__ */ #endif /* _LINUX_ANNOTATE_H */ -- cgit v1.2.3 From 305c8dc477175eb29df18accc95c868acd2cdd4e Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 2 Dec 2025 09:59:38 -0800 Subject: objtool: Consolidate annotation macros Consolidate __ASM_ANNOTATE into a single macro which is used by both C and asm. This also makes the code generation a bit more palatable by putting it all on a single line. Turn this: 911: .pushsection .discard.annotate_insn,"M", @progbits, 8 .long 911b - . .long 1 .popsection jmp __x86_return_thunk Into: 911: .pushsection ".discard.annotate_insn", "M", @progbits, 8; .long 911b - .; .long 1; .popsection jmp __x86_return_thunk Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://patch.msgid.link/c05ff40d3383e85c3b59018ef0b3c7aaf993a60d.1764694625.git.jpoimboe@kernel.org --- include/linux/annotate.h | 36 +++++++++++++++--------------------- 1 file changed, 15 insertions(+), 21 deletions(-) (limited to 'include/linux/annotate.h') diff --git a/include/linux/annotate.h b/include/linux/annotate.h index 7c10d34d198c..996126f5f9ec 100644 --- a/include/linux/annotate.h +++ b/include/linux/annotate.h @@ -6,41 +6,35 @@ #ifdef CONFIG_OBJTOOL -#ifndef __ASSEMBLY__ - #define __ASM_ANNOTATE(section, label, type) \ - ".pushsection " section ",\"M\", @progbits, 8\n\t" \ - ".long " __stringify(label) " - .\n\t" \ - ".long " __stringify(type) "\n\t" \ - ".popsection\n\t" + .pushsection section, "M", @progbits, 8; \ + .long label - .; \ + .long type; \ + .popsection + +#ifndef __ASSEMBLY__ #define ASM_ANNOTATE_LABEL(label, type) \ - __ASM_ANNOTATE(".discard.annotate_insn", label, type) + __stringify(__ASM_ANNOTATE(".discard.annotate_insn", label, type)) "\n\t" #define ASM_ANNOTATE(type) \ - "911:\n\t" \ - ASM_ANNOTATE_LABEL(911b, type) + "911: " \ + __stringify(__ASM_ANNOTATE(".discard.annotate_insn", 911b, type)) "\n\t" #define ASM_ANNOTATE_DATA(type) \ - "912:\n\t" \ - __ASM_ANNOTATE(".discard.annotate_data", 912b, type) + "912: " \ + __stringify(__ASM_ANNOTATE(".discard.annotate_data", 912b, type)) "\n\t" #else /* __ASSEMBLY__ */ -.macro __ANNOTATE section, type -.Lhere_\@: - .pushsection \section, "M", @progbits, 8 - .long .Lhere_\@ - . - .long \type - .popsection -.endm - .macro ANNOTATE type - __ANNOTATE ".discard.annotate_insn", \type +.Lhere_\@: + __ASM_ANNOTATE(".discard.annotate_insn", .Lhere_\@, \type) .endm .macro ANNOTATE_DATA type - __ANNOTATE ".discard.annotate_data", \type +.Lhere_\@: + __ASM_ANNOTATE(".discard.annotate_data", .Lhere_\@, \type) .endm #endif /* __ASSEMBLY__ */ -- cgit v1.2.3 From ed3bf863dc9150b56233b01ec073cbbd1fc9c6a3 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 2 Dec 2025 09:59:39 -0800 Subject: objtool: Remove newlines and tabs from annotation macros Remove newlines and tabs from the annotation macros so the invoking code can insert them as needed to match the style of the surrounding code. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://patch.msgid.link/66305834c2eb78f082217611b756231ae9c0b555.1764694625.git.jpoimboe@kernel.org --- include/linux/annotate.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux/annotate.h') diff --git a/include/linux/annotate.h b/include/linux/annotate.h index 996126f5f9ec..5efac5d4f9cf 100644 --- a/include/linux/annotate.h +++ b/include/linux/annotate.h @@ -15,15 +15,15 @@ #ifndef __ASSEMBLY__ #define ASM_ANNOTATE_LABEL(label, type) \ - __stringify(__ASM_ANNOTATE(".discard.annotate_insn", label, type)) "\n\t" + __stringify(__ASM_ANNOTATE(".discard.annotate_insn", label, type)) #define ASM_ANNOTATE(type) \ "911: " \ - __stringify(__ASM_ANNOTATE(".discard.annotate_insn", 911b, type)) "\n\t" + __stringify(__ASM_ANNOTATE(".discard.annotate_insn", 911b, type)) #define ASM_ANNOTATE_DATA(type) \ "912: " \ - __stringify(__ASM_ANNOTATE(".discard.annotate_data", 912b, type)) "\n\t" + __stringify(__ASM_ANNOTATE(".discard.annotate_data", 912b, type)) #else /* __ASSEMBLY__ */ -- cgit v1.2.3 From 2d3451ef1ef679ae496f8e335f4b1305885e8083 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 3 Dec 2025 10:07:38 -0800 Subject: objtool: Simplify .annotate_insn code generation output some more Remove the superfluous section name quotes, and combine the longs into a single command. Before: 911: .pushsection ".discard.annotate_insn", "M", @progbits, 8; .long 911b - .; .long 2; .popsection After: 911: .pushsection .discard.annotate_insn, "M", @progbits, 8; .long 911b - ., 2; .popsection No change in functionality. Suggested-by: Linus Torvalds Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Link: https://patch.msgid.link/hpsfcihgqmhcdrg7pop7z73ptymakgjq7qlxrawrjxilosk43l@xikqif3ievj4 --- include/linux/annotate.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'include/linux/annotate.h') diff --git a/include/linux/annotate.h b/include/linux/annotate.h index 5efac5d4f9cf..2f1599c9e573 100644 --- a/include/linux/annotate.h +++ b/include/linux/annotate.h @@ -8,33 +8,32 @@ #define __ASM_ANNOTATE(section, label, type) \ .pushsection section, "M", @progbits, 8; \ - .long label - .; \ - .long type; \ + .long label - ., type; \ .popsection #ifndef __ASSEMBLY__ #define ASM_ANNOTATE_LABEL(label, type) \ - __stringify(__ASM_ANNOTATE(".discard.annotate_insn", label, type)) + __stringify(__ASM_ANNOTATE(.discard.annotate_insn, label, type)) #define ASM_ANNOTATE(type) \ "911: " \ - __stringify(__ASM_ANNOTATE(".discard.annotate_insn", 911b, type)) + __stringify(__ASM_ANNOTATE(.discard.annotate_insn, 911b, type)) #define ASM_ANNOTATE_DATA(type) \ "912: " \ - __stringify(__ASM_ANNOTATE(".discard.annotate_data", 912b, type)) + __stringify(__ASM_ANNOTATE(.discard.annotate_data, 912b, type)) #else /* __ASSEMBLY__ */ .macro ANNOTATE type .Lhere_\@: - __ASM_ANNOTATE(".discard.annotate_insn", .Lhere_\@, \type) + __ASM_ANNOTATE(.discard.annotate_insn, .Lhere_\@, \type) .endm .macro ANNOTATE_DATA type .Lhere_\@: - __ASM_ANNOTATE(".discard.annotate_data", .Lhere_\@, \type) + __ASM_ANNOTATE(.discard.annotate_data, .Lhere_\@, \type) .endm #endif /* __ASSEMBLY__ */ -- cgit v1.2.3