/* SPDX-License-Identifier: GPL-2.0 */#ifndef _LINUX_OBJTOOL_H#define _LINUX_OBJTOOL_H #ifndef __ASSEMBLY__ #include <linux/types.h> /* * This struct is used by asm and inline asm code to manually annotate the * location of registers on the stack. */struct unwind_hint {	u32		ip;	s16		sp_offset;	u8		sp_reg;	u8		type;	u8		end;};#endif /* * UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP * (the caller's SP right before it made the call).  Used for all callable * functions, i.e. all C code and all callable asm functions. * * UNWIND_HINT_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset * points to a fully populated pt_regs from a syscall, interrupt, or exception. * * UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that * sp_reg+sp_offset points to the iret return frame. * * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function. * Useful for code which doesn't have an ELF function annotation. */#define UNWIND_HINT_TYPE_CALL		0#define UNWIND_HINT_TYPE_REGS		1#define UNWIND_HINT_TYPE_REGS_PARTIAL	2#define UNWIND_HINT_TYPE_FUNC		3 #ifdef CONFIG_STACK_VALIDATION #ifndef __ASSEMBLY__ #define UNWIND_HINT(sp_reg, sp_offset, type, end)		\	"987: \n\t"						\	".pushsection .discard.unwind_hints\n\t"		\	/* struct unwind_hint */				\	".long 987b - .\n\t"					\	".short " __stringify(sp_offset) "\n\t"			\	".byte " __stringify(sp_reg) "\n\t"			\	".byte " __stringify(type) "\n\t"			\	".byte " __stringify(end) "\n\t"			\	".balign 4 \n\t"					\	".popsection\n\t" /* * This macro marks the given function's stack frame as "non-standard", which * tells objtool to ignore the function when doing stack metadata validation. * It should only be used in special cases where you're 100% sure it won't * affect the reliability of frame pointers and kernel stack traces. * * For more information, see tools/objtool/Documentation/stack-validation.txt. */#define STACK_FRAME_NON_STANDARD(func) \	static void __used __section(".discard.func_stack_frame_non_standard") \		*__func_stack_frame_non_standard_##func = func /* * STACK_FRAME_NON_STANDARD_FP() is a frame-pointer-specific function ignore * for the case where a function is intentionally missing frame pointer setup, * but otherwise needs objtool/ORC coverage when frame pointers are disabled. */#ifdef CONFIG_FRAME_POINTER#define STACK_FRAME_NON_STANDARD_FP(func) STACK_FRAME_NON_STANDARD(func)#else#define STACK_FRAME_NON_STANDARD_FP(func)#endif #else /* __ASSEMBLY__ */ /* * 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				\	999:							\	.pushsection .discard.intra_function_calls;		\	.long 999b;						\	.popsection; /* * In asm, there are two kinds of code: normal C-type callable functions and * the rest.  The normal callable functions can be called by other code, and * don't do anything unusual with the stack.  Such normal callable functions * are annotated with the ENTRY/ENDPROC macros.  Most asm code falls in this * category.  In this case, no special debugging annotations are needed because * objtool can automatically generate the ORC data for the ORC unwinder to read * at runtime. * * Anything which doesn't fall into the above category, such as syscall and * interrupt handlers, tends to not be called directly by other functions, and * often does unusual non-C-function-type things with the stack pointer.  Such * code needs to be annotated such that objtool can understand it.  The * following CFI hint macros are for this type of code. * * These macros provide hints to objtool about the state of the stack at each * instruction.  Objtool starts from the hints and follows the code flow, * making automatic CFI adjustments when it sees pushes and pops, filling out * the debuginfo as necessary.  It will also warn if it sees any * inconsistencies. */.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0.Lunwind_hint_ip_\@:	.pushsection .discard.unwind_hints		/* struct unwind_hint */		.long .Lunwind_hint_ip_\@ - .		.short \sp_offset		.byte \sp_reg		.byte \type		.byte \end		.balign 4	.popsection.endm .macro STACK_FRAME_NON_STANDARD func:req	.pushsection .discard.func_stack_frame_non_standard, "aw"		.long \func - .	.popsection.endm #endif /* __ASSEMBLY__ */ #else /* !CONFIG_STACK_VALIDATION */ #ifndef __ASSEMBLY__ #define UNWIND_HINT(sp_reg, sp_offset, type, end)	\	"\n\t"#define STACK_FRAME_NON_STANDARD(func)#define STACK_FRAME_NON_STANDARD_FP(func)#else#define ANNOTATE_INTRA_FUNCTION_CALL.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0.endm.macro STACK_FRAME_NON_STANDARD func:req.endm#endif #endif /* CONFIG_STACK_VALIDATION */ #endif /* _LINUX_OBJTOOL_H */