| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | |
| 3 | #include <linux/stringify.h> |
| 4 | #include <linux/linkage.h> |
| 5 | #include <asm/dwarf2.h> |
| 6 | #include <asm/cpufeatures.h> |
| 7 | #include <asm/alternative-asm.h> |
| 8 | #include <asm/export.h> |
| 9 | #include <asm/nospec-branch.h> |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 10 | #include <asm/unwind_hints.h> |
| 11 | #include <asm/frame.h> |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 12 | |
| 13 | .macro THUNK reg |
| 14 | .section .text.__x86.indirect_thunk |
| 15 | |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 16 | .align 32 |
| 17 | SYM_FUNC_START(__x86_indirect_thunk_\reg) |
| 18 | JMP_NOSPEC \reg |
| 19 | SYM_FUNC_END(__x86_indirect_thunk_\reg) |
| 20 | |
| 21 | SYM_FUNC_START_NOALIGN(__x86_retpoline_\reg) |
| 22 | ANNOTATE_INTRA_FUNCTION_CALL |
| 23 | call .Ldo_rop_\@ |
| 24 | .Lspec_trap_\@: |
| 25 | UNWIND_HINT_EMPTY |
| 26 | pause |
| 27 | lfence |
| 28 | jmp .Lspec_trap_\@ |
| 29 | .Ldo_rop_\@: |
| 30 | mov %\reg, (%_ASM_SP) |
| 31 | UNWIND_HINT_RET_OFFSET |
| 32 | ret |
| 33 | SYM_FUNC_END(__x86_retpoline_\reg) |
| 34 | |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 35 | .endm |
| 36 | |
| 37 | /* |
| 38 | * Despite being an assembler file we can't just use .irp here |
| 39 | * because __KSYM_DEPS__ only uses the C preprocessor and would |
| 40 | * only see one instance of "__x86_indirect_thunk_\reg" rather |
| 41 | * than one per register with the correct names. So we do it |
| 42 | * the simple and nasty way... |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 43 | * |
| 44 | * Worse, you can only have a single EXPORT_SYMBOL per line, |
| 45 | * and CPP can't insert newlines, so we have to repeat everything |
| 46 | * at least twice. |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 47 | */ |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 48 | |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 49 | #define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym) |
| 50 | #define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg) |
| 51 | #define EXPORT_RETPOLINE(reg) __EXPORT_THUNK(__x86_retpoline_ ## reg) |
| 52 | |
| 53 | #undef GEN |
| 54 | #define GEN(reg) THUNK reg |
| 55 | #include <asm/GEN-for-each-reg.h> |
| 56 | |
| 57 | #undef GEN |
| 58 | #define GEN(reg) EXPORT_THUNK(reg) |
| 59 | #include <asm/GEN-for-each-reg.h> |
| 60 | |
| 61 | #undef GEN |
| 62 | #define GEN(reg) EXPORT_RETPOLINE(reg) |
| 63 | #include <asm/GEN-for-each-reg.h> |