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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_OBJTOOL_H
#define _LINUX_OBJTOOL_H
#include <linux/objtool_types.h>
#ifdef CONFIG_OBJTOOL
#include <asm/asm.h>
#ifndef __ASSEMBLY__
#define UNWIND_HINT(type, sp_reg, sp_offset, signal) \
"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(signal) "\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/objtool.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
#define ANNOTATE_NOENDBR \
"986: \n\t" \
".pushsection .discard.noendbr\n\t" \
".long 986b\n\t" \
".popsection\n\t"
#define ASM_REACHABLE \
"998:\n\t" \
".pushsection .discard.reachable\n\t" \
".long 998b\n\t" \
".popsection\n\t"
#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 type:req sp_reg=0 sp_offset=0 signal=0
.Lhere_\@:
.pushsection .discard.unwind_hints
/* struct unwind_hint */
.long .Lhere_\@ - .
.short \sp_offset
.byte \sp_reg
.byte \type
.byte \signal
.balign 4
.popsection
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.pushsection .discard.func_stack_frame_non_standard, "aw"
.long \func - .
.popsection
.endm
.macro STACK_FRAME_NON_STANDARD_FP func:req
#ifdef CONFIG_FRAME_POINTER
STACK_FRAME_NON_STANDARD \func
#endif
.endm
.macro ANNOTATE_NOENDBR
.Lhere_\@:
.pushsection .discard.noendbr
.long .Lhere_\@
.popsection
.endm
/*
* 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.
*/
.macro VALIDATE_UNRET_BEGIN
#if defined(CONFIG_NOINSTR_VALIDATION) && \
(defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO))
.Lhere_\@:
.pushsection .discard.validate_unret
.long .Lhere_\@ - .
.popsection
#endif
.endm
.macro REACHABLE
.Lhere_\@:
.pushsection .discard.reachable
.long .Lhere_\@
.popsection
.endm
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_OBJTOOL */
#ifndef __ASSEMBLY__
#define UNWIND_HINT(type, sp_reg, sp_offset, signal) "\n\t"
#define STACK_FRAME_NON_STANDARD(func)
#define STACK_FRAME_NON_STANDARD_FP(func)
#define ANNOTATE_NOENDBR
#define ASM_REACHABLE
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
.macro ANNOTATE_NOENDBR
.endm
.macro REACHABLE
.endm
#endif
#endif /* CONFIG_OBJTOOL */
#endif /* _LINUX_OBJTOOL_H */
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