| /* 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) |
| |
| STACK_FRAME_NON_STANDARD(__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) |
| |
| STACK_FRAME_NON_STANDARD(__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> |
