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#ifndef _ASM_X86_UNWIND_HINTS_H
#define _ASM_X86_UNWIND_HINTS_H
#include "orc_types.h"
#ifdef __ASSEMBLY__
/*
* 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=ORC_REG_SP sp_offset=0 type=ORC_TYPE_CALL end=0
#ifdef CONFIG_STACK_VALIDATION
.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
#endif
.endm
.macro UNWIND_HINT_EMPTY
UNWIND_HINT sp_reg=ORC_REG_UNDEFINED end=1
.endm
.macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 iret=0
.if \base == %rsp
.if \indirect
.set sp_reg, ORC_REG_SP_INDIRECT
.else
.set sp_reg, ORC_REG_SP
.endif
.elseif \base == %rbp
.set sp_reg, ORC_REG_BP
.elseif \base == %rdi
.set sp_reg, ORC_REG_DI
.elseif \base == %rdx
.set sp_reg, ORC_REG_DX
.elseif \base == %r10
.set sp_reg, ORC_REG_R10
.else
.error "UNWIND_HINT_REGS: bad base register"
.endif
.set sp_offset, \offset
.if \iret
.set type, ORC_TYPE_REGS_IRET
.elseif \extra == 0
.set type, ORC_TYPE_REGS_IRET
.set sp_offset, \offset + (16*8)
.else
.set type, ORC_TYPE_REGS
.endif
UNWIND_HINT sp_reg=sp_reg sp_offset=sp_offset type=type
.endm
.macro UNWIND_HINT_IRET_REGS base=%rsp offset=0
UNWIND_HINT_REGS base=\base offset=\offset iret=1
.endm
.macro UNWIND_HINT_FUNC sp_offset=8
UNWIND_HINT sp_offset=\sp_offset
.endm
#else /* !__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"
#define UNWIND_HINT_SAVE UNWIND_HINT(0, 0, UNWIND_HINT_TYPE_SAVE, 0)
#define UNWIND_HINT_EMPTY
#define UNWIND_HINT_RESTORE UNWIND_HINT(0, 0, UNWIND_HINT_TYPE_RESTORE, 0)
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_UNWIND_HINTS_H */
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