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/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/stringify.h>
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/cpufeatures.h>
#include <asm/alternative.h>
#include <asm/export.h>
#include <asm/nospec-branch.h>
#include <asm/unwind_hints.h>
#include <asm/frame.h>
.section .text.__x86.indirect_thunk
.macro RETPOLINE reg
ANNOTATE_INTRA_FUNCTION_CALL
call .Ldo_rop_\@
.Lspec_trap_\@:
UNWIND_HINT_EMPTY
pause
lfence
jmp .Lspec_trap_\@
.Ldo_rop_\@:
mov %\reg, (%_ASM_SP)
UNWIND_HINT_FUNC
ret
.endm
.macro THUNK reg
.align 32
SYM_FUNC_START(__x86_indirect_thunk_\reg)
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
__stringify(RETPOLINE \reg), X86_FEATURE_RETPOLINE, \
__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD
SYM_FUNC_END(__x86_indirect_thunk_\reg)
.endm
/*
* This generates .altinstr_replacement symbols for use by objtool. They,
* however, must not actually live in .altinstr_replacement since that will be
* discarded after init, but module alternatives will also reference these
* symbols.
*
* Their names matches the "__x86_indirect_" prefix to mark them as retpolines.
*/
.macro ALT_THUNK reg
.align 1
SYM_FUNC_START_NOALIGN(__x86_indirect_alt_call_\reg)
ANNOTATE_RETPOLINE_SAFE
1: call *%\reg
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_call_\reg)
SYM_FUNC_START_NOALIGN(__x86_indirect_alt_jmp_\reg)
ANNOTATE_RETPOLINE_SAFE
1: jmp *%\reg
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_jmp_\reg)
.endm
/*
* Despite being an assembler file we can't just use .irp here
* because __KSYM_DEPS__ only uses the C preprocessor and would
* only see one instance of "__x86_indirect_thunk_\reg" rather
* than one per register with the correct names. So we do it
* the simple and nasty way...
*
* Worse, you can only have a single EXPORT_SYMBOL per line,
* and CPP can't insert newlines, so we have to repeat everything
* at least twice.
*/
#define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym)
#define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg)
#undef GEN
#define GEN(reg) THUNK reg
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) EXPORT_THUNK(reg)
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) ALT_THUNK reg
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_call_ ## reg)
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_jmp_ ## reg)
#include <asm/GEN-for-each-reg.h>
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