diff options
Diffstat (limited to 'tools/objtool/arch/x86')
-rw-r--r-- | tools/objtool/arch/x86/Build | 1 | ||||
-rw-r--r-- | tools/objtool/arch/x86/decode.c | 19 | ||||
-rw-r--r-- | tools/objtool/arch/x86/orc.c | 188 | ||||
-rw-r--r-- | tools/objtool/arch/x86/special.c | 2 |
4 files changed, 204 insertions, 6 deletions
diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build index 9f7869b5c5..3dedb2fd8f 100644 --- a/tools/objtool/arch/x86/Build +++ b/tools/objtool/arch/x86/Build @@ -1,5 +1,6 @@ objtool-y += special.o objtool-y += decode.o +objtool-y += orc.o inat_tables_script = ../arch/x86/tools/gen-insn-attr-x86.awk inat_tables_maps = ../arch/x86/lib/x86-opcode-map.txt diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index e327cd8271..3a1d80a787 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -509,11 +509,20 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec if (op2 == 0x01) { - if (modrm == 0xca) - insn->type = INSN_CLAC; - else if (modrm == 0xcb) - insn->type = INSN_STAC; - + switch (insn_last_prefix_id(&ins)) { + case INAT_PFX_REPE: + case INAT_PFX_REPNE: + if (modrm == 0xca) + /* eretu/erets */ + insn->type = INSN_CONTEXT_SWITCH; + break; + default: + if (modrm == 0xca) + insn->type = INSN_CLAC; + else if (modrm == 0xcb) + insn->type = INSN_STAC; + break; + } } else if (op2 >= 0x80 && op2 <= 0x8f) { insn->type = INSN_JUMP_CONDITIONAL; diff --git a/tools/objtool/arch/x86/orc.c b/tools/objtool/arch/x86/orc.c new file mode 100644 index 0000000000..b6cd943e87 --- /dev/null +++ b/tools/objtool/arch/x86/orc.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <linux/objtool_types.h> +#include <asm/orc_types.h> + +#include <objtool/check.h> +#include <objtool/orc.h> +#include <objtool/warn.h> +#include <objtool/endianness.h> + +int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn) +{ + struct cfi_reg *bp = &cfi->regs[CFI_BP]; + + memset(orc, 0, sizeof(*orc)); + + if (!cfi) { + /* + * This is usually either unreachable nops/traps (which don't + * trigger unreachable instruction warnings), or + * STACK_FRAME_NON_STANDARD functions. + */ + orc->type = ORC_TYPE_UNDEFINED; + return 0; + } + + switch (cfi->type) { + case UNWIND_HINT_TYPE_UNDEFINED: + orc->type = ORC_TYPE_UNDEFINED; + return 0; + case UNWIND_HINT_TYPE_END_OF_STACK: + orc->type = ORC_TYPE_END_OF_STACK; + return 0; + case UNWIND_HINT_TYPE_CALL: + orc->type = ORC_TYPE_CALL; + break; + case UNWIND_HINT_TYPE_REGS: + orc->type = ORC_TYPE_REGS; + break; + case UNWIND_HINT_TYPE_REGS_PARTIAL: + orc->type = ORC_TYPE_REGS_PARTIAL; + break; + default: + WARN_INSN(insn, "unknown unwind hint type %d", cfi->type); + return -1; + } + + orc->signal = cfi->signal; + + switch (cfi->cfa.base) { + case CFI_SP: + orc->sp_reg = ORC_REG_SP; + break; + case CFI_SP_INDIRECT: + orc->sp_reg = ORC_REG_SP_INDIRECT; + break; + case CFI_BP: + orc->sp_reg = ORC_REG_BP; + break; + case CFI_BP_INDIRECT: + orc->sp_reg = ORC_REG_BP_INDIRECT; + break; + case CFI_R10: + orc->sp_reg = ORC_REG_R10; + break; + case CFI_R13: + orc->sp_reg = ORC_REG_R13; + break; + case CFI_DI: + orc->sp_reg = ORC_REG_DI; + break; + case CFI_DX: + orc->sp_reg = ORC_REG_DX; + break; + default: + WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base); + return -1; + } + + switch (bp->base) { + case CFI_UNDEFINED: + orc->bp_reg = ORC_REG_UNDEFINED; + break; + case CFI_CFA: + orc->bp_reg = ORC_REG_PREV_SP; + break; + case CFI_BP: + orc->bp_reg = ORC_REG_BP; + break; + default: + WARN_INSN(insn, "unknown BP base reg %d", bp->base); + return -1; + } + + orc->sp_offset = cfi->cfa.offset; + orc->bp_offset = bp->offset; + + return 0; +} + +int write_orc_entry(struct elf *elf, struct section *orc_sec, + struct section *ip_sec, unsigned int idx, + struct section *insn_sec, unsigned long insn_off, + struct orc_entry *o) +{ + struct orc_entry *orc; + + /* populate ORC data */ + orc = (struct orc_entry *)orc_sec->data->d_buf + idx; + memcpy(orc, o, sizeof(*orc)); + orc->sp_offset = bswap_if_needed(elf, orc->sp_offset); + orc->bp_offset = bswap_if_needed(elf, orc->bp_offset); + + /* populate reloc for ip */ + if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx, + insn_sec, insn_off)) + return -1; + + return 0; +} + +static const char *reg_name(unsigned int reg) +{ + switch (reg) { + case ORC_REG_PREV_SP: + return "prevsp"; + case ORC_REG_DX: + return "dx"; + case ORC_REG_DI: + return "di"; + case ORC_REG_BP: + return "bp"; + case ORC_REG_SP: + return "sp"; + case ORC_REG_R10: + return "r10"; + case ORC_REG_R13: + return "r13"; + case ORC_REG_BP_INDIRECT: + return "bp(ind)"; + case ORC_REG_SP_INDIRECT: + return "sp(ind)"; + default: + return "?"; + } +} + +static const char *orc_type_name(unsigned int type) +{ + switch (type) { + case ORC_TYPE_UNDEFINED: + return "(und)"; + case ORC_TYPE_END_OF_STACK: + return "end"; + case ORC_TYPE_CALL: + return "call"; + case ORC_TYPE_REGS: + return "regs"; + case ORC_TYPE_REGS_PARTIAL: + return "regs (partial)"; + default: + return "?"; + } +} + +static void print_reg(unsigned int reg, int offset) +{ + if (reg == ORC_REG_BP_INDIRECT) + printf("(bp%+d)", offset); + else if (reg == ORC_REG_SP_INDIRECT) + printf("(sp)%+d", offset); + else if (reg == ORC_REG_UNDEFINED) + printf("(und)"); + else + printf("%s%+d", reg_name(reg), offset); +} + +void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i) +{ + printf("type:%s", orc_type_name(orc[i].type)); + + printf(" sp:"); + print_reg(orc[i].sp_reg, bswap_if_needed(dummy_elf, orc[i].sp_offset)); + + printf(" bp:"); + print_reg(orc[i].bp_reg, bswap_if_needed(dummy_elf, orc[i].bp_offset)); + + printf(" signal:%d\n", orc[i].signal); +} diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index 29e949579e..4134d27c69 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -83,7 +83,7 @@ bool arch_support_alt_relocation(struct special_alt *special_alt, * TODO: Once we have DWARF CFI and smarter instruction decoding logic, * ensure the same register is used in the mov and jump instructions. * - * NOTE: RETPOLINE made it harder still to decode dynamic jumps. + * NOTE: MITIGATION_RETPOLINE made it harder still to decode dynamic jumps. */ struct reloc *arch_find_switch_table(struct objtool_file *file, struct instruction *insn) |