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