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Diffstat (limited to 'include/linux/annotate.h')
| -rw-r--r-- | include/linux/annotate.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/include/linux/annotate.h b/include/linux/annotate.h new file mode 100644 index 000000000000..2f1599c9e573 --- /dev/null +++ b/include/linux/annotate.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_ANNOTATE_H +#define _LINUX_ANNOTATE_H + +#include <linux/objtool_types.h> + +#ifdef CONFIG_OBJTOOL + +#define __ASM_ANNOTATE(section, label, type) \ + .pushsection section, "M", @progbits, 8; \ + .long label - ., type; \ + .popsection + +#ifndef __ASSEMBLY__ + +#define ASM_ANNOTATE_LABEL(label, type) \ + __stringify(__ASM_ANNOTATE(.discard.annotate_insn, label, type)) + +#define ASM_ANNOTATE(type) \ + "911: " \ + __stringify(__ASM_ANNOTATE(.discard.annotate_insn, 911b, type)) + +#define ASM_ANNOTATE_DATA(type) \ + "912: " \ + __stringify(__ASM_ANNOTATE(.discard.annotate_data, 912b, type)) + +#else /* __ASSEMBLY__ */ + +.macro ANNOTATE type +.Lhere_\@: + __ASM_ANNOTATE(.discard.annotate_insn, .Lhere_\@, \type) +.endm + +.macro ANNOTATE_DATA type +.Lhere_\@: + __ASM_ANNOTATE(.discard.annotate_data, .Lhere_\@, \type) +.endm + +#endif /* __ASSEMBLY__ */ + +#else /* !CONFIG_OBJTOOL */ +#ifndef __ASSEMBLY__ +#define ASM_ANNOTATE_LABEL(label, type) "" +#define ASM_ANNOTATE(type) +#define ASM_ANNOTATE_DATA(type) +#else /* __ASSEMBLY__ */ +.macro ANNOTATE type +.endm +.macro ANNOTATE_DATA type +.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_LABEL(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(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). + */ +#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(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_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 +#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 +#define ANNOTATE_DATA_SPECIAL ANNOTATE_DATA type=ANNOTYPE_DATA_SPECIAL +#endif /* __ASSEMBLY__ */ + +#endif /* _LINUX_ANNOTATE_H */ |