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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _LINUX_OBJTOOL_H3#define _LINUX_OBJTOOL_H4 5#include <linux/objtool_types.h>6 7#ifdef CONFIG_OBJTOOL8 9#include <asm/asm.h>10 11#ifndef __ASSEMBLY__12 13#define UNWIND_HINT(type, sp_reg, sp_offset, signal) \14 "987: \n\t" \15 ".pushsection .discard.unwind_hints\n\t" \16 /* struct unwind_hint */ \17 ".long 987b - .\n\t" \18 ".short " __stringify(sp_offset) "\n\t" \19 ".byte " __stringify(sp_reg) "\n\t" \20 ".byte " __stringify(type) "\n\t" \21 ".byte " __stringify(signal) "\n\t" \22 ".balign 4 \n\t" \23 ".popsection\n\t"24 25/*26 * This macro marks the given function's stack frame as "non-standard", which27 * tells objtool to ignore the function when doing stack metadata validation.28 * It should only be used in special cases where you're 100% sure it won't29 * affect the reliability of frame pointers and kernel stack traces.30 *31 * For more information, see tools/objtool/Documentation/objtool.txt.32 */33#define STACK_FRAME_NON_STANDARD(func) \34 static void __used __section(".discard.func_stack_frame_non_standard") \35 *__func_stack_frame_non_standard_##func = func36 37/*38 * STACK_FRAME_NON_STANDARD_FP() is a frame-pointer-specific function ignore39 * for the case where a function is intentionally missing frame pointer setup,40 * but otherwise needs objtool/ORC coverage when frame pointers are disabled.41 */42#ifdef CONFIG_FRAME_POINTER43#define STACK_FRAME_NON_STANDARD_FP(func) STACK_FRAME_NON_STANDARD(func)44#else45#define STACK_FRAME_NON_STANDARD_FP(func)46#endif47 48#define ANNOTATE_NOENDBR \49 "986: \n\t" \50 ".pushsection .discard.noendbr\n\t" \51 ".long 986b\n\t" \52 ".popsection\n\t"53 54#define ASM_REACHABLE \55 "998:\n\t" \56 ".pushsection .discard.reachable\n\t" \57 ".long 998b\n\t" \58 ".popsection\n\t"59 60#else /* __ASSEMBLY__ */61 62/*63 * This macro indicates that the following intra-function call is valid.64 * Any non-annotated intra-function call will cause objtool to issue a warning.65 */66#define ANNOTATE_INTRA_FUNCTION_CALL \67 999: \68 .pushsection .discard.intra_function_calls; \69 .long 999b; \70 .popsection;71 72/*73 * In asm, there are two kinds of code: normal C-type callable functions and74 * the rest. The normal callable functions can be called by other code, and75 * don't do anything unusual with the stack. Such normal callable functions76 * are annotated with the ENTRY/ENDPROC macros. Most asm code falls in this77 * category. In this case, no special debugging annotations are needed because78 * objtool can automatically generate the ORC data for the ORC unwinder to read79 * at runtime.80 *81 * Anything which doesn't fall into the above category, such as syscall and82 * interrupt handlers, tends to not be called directly by other functions, and83 * often does unusual non-C-function-type things with the stack pointer. Such84 * code needs to be annotated such that objtool can understand it. The85 * following CFI hint macros are for this type of code.86 *87 * These macros provide hints to objtool about the state of the stack at each88 * instruction. Objtool starts from the hints and follows the code flow,89 * making automatic CFI adjustments when it sees pushes and pops, filling out90 * the debuginfo as necessary. It will also warn if it sees any91 * inconsistencies.92 */93.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=094.Lhere_\@:95 .pushsection .discard.unwind_hints96 /* struct unwind_hint */97 .long .Lhere_\@ - .98 .short \sp_offset99 .byte \sp_reg100 .byte \type101 .byte \signal102 .balign 4103 .popsection104.endm105 106.macro STACK_FRAME_NON_STANDARD func:req107 .pushsection .discard.func_stack_frame_non_standard, "aw"108 .long \func - .109 .popsection110.endm111 112.macro STACK_FRAME_NON_STANDARD_FP func:req113#ifdef CONFIG_FRAME_POINTER114 STACK_FRAME_NON_STANDARD \func115#endif116.endm117 118.macro ANNOTATE_NOENDBR119.Lhere_\@:120 .pushsection .discard.noendbr121 .long .Lhere_\@122 .popsection123.endm124 125/*126 * Use objtool to validate the entry requirement that all code paths do127 * VALIDATE_UNRET_END before RET.128 *129 * NOTE: The macro must be used at the beginning of a global symbol, otherwise130 * it will be ignored.131 */132.macro VALIDATE_UNRET_BEGIN133#if defined(CONFIG_NOINSTR_VALIDATION) && \134 (defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO))135.Lhere_\@:136 .pushsection .discard.validate_unret137 .long .Lhere_\@ - .138 .popsection139#endif140.endm141 142.macro REACHABLE143.Lhere_\@:144 .pushsection .discard.reachable145 .long .Lhere_\@146 .popsection147.endm148 149#endif /* __ASSEMBLY__ */150 151#else /* !CONFIG_OBJTOOL */152 153#ifndef __ASSEMBLY__154 155#define UNWIND_HINT(type, sp_reg, sp_offset, signal) "\n\t"156#define STACK_FRAME_NON_STANDARD(func)157#define STACK_FRAME_NON_STANDARD_FP(func)158#define ANNOTATE_NOENDBR159#define ASM_REACHABLE160#else161#define ANNOTATE_INTRA_FUNCTION_CALL162.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0163.endm164.macro STACK_FRAME_NON_STANDARD func:req165.endm166.macro ANNOTATE_NOENDBR167.endm168.macro REACHABLE169.endm170#endif171 172#endif /* CONFIG_OBJTOOL */173 174#endif /* _LINUX_OBJTOOL_H */175