diff options
Diffstat (limited to 'tools/objtool')
-rw-r--r-- | tools/objtool/Documentation/stack-validation.txt | 6 | ||||
-rw-r--r-- | tools/objtool/Makefile | 1 | ||||
-rw-r--r-- | tools/objtool/arch/x86/decode.c | 17 | ||||
-rw-r--r-- | tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk | 1 | ||||
-rw-r--r-- | tools/objtool/check.c | 52 | ||||
-rw-r--r-- | tools/objtool/elf.c | 33 |
6 files changed, 72 insertions, 38 deletions
diff --git a/tools/objtool/Documentation/stack-validation.txt b/tools/objtool/Documentation/stack-validation.txt index 6a1af43862df..3995735a878f 100644 --- a/tools/objtool/Documentation/stack-validation.txt +++ b/tools/objtool/Documentation/stack-validation.txt @@ -194,10 +194,10 @@ they mean, and suggestions for how to fix them. If it's a GCC-compiled .c file, the error may be because the function uses an inline asm() statement which has a "call" instruction. An asm() statement with a call instruction must declare the use of the - stack pointer in its output operand. For example, on x86_64: + stack pointer in its output operand. On x86_64, this means adding + the ASM_CALL_CONSTRAINT as an output constraint: - register void *__sp asm("rsp"); - asm volatile("call func" : "+r" (__sp)); + asm volatile("call func" : ASM_CALL_CONSTRAINT); Otherwise the stack frame may not get created before the call. diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index 6976c73e60c4..424b1965d06f 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 include ../scripts/Makefile.include include ../scripts/Makefile.arch diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 0e8c8ec4fd4e..34a579f806e3 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -208,14 +208,14 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, break; case 0x89: - if (rex == 0x48 && modrm == 0xe5) { + if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) { - /* mov %rsp, %rbp */ + /* mov %rsp, reg */ *type = INSN_STACK; op->src.type = OP_SRC_REG; op->src.reg = CFI_SP; op->dest.type = OP_DEST_REG; - op->dest.reg = CFI_BP; + op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b]; break; } @@ -284,11 +284,16 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, case 0x8d: if (sib == 0x24 && rex_w && !rex_b && !rex_x) { - /* lea disp(%rsp), reg */ *type = INSN_STACK; - op->src.type = OP_SRC_ADD; + if (!insn.displacement.value) { + /* lea (%rsp), reg */ + op->src.type = OP_SRC_REG; + } else { + /* lea disp(%rsp), reg */ + op->src.type = OP_SRC_ADD; + op->src.offset = insn.displacement.value; + } op->src.reg = CFI_SP; - op->src.offset = insn.displacement.value; op->dest.type = OP_DEST_REG; op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; diff --git a/tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk b/tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk index a3d2c62fd805..b02a36b2c14f 100644 --- a/tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk +++ b/tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk @@ -1,4 +1,5 @@ #!/bin/awk -f +# SPDX-License-Identifier: GPL-2.0 # gen-insn-attr-x86.awk: Instruction attribute table generator # Written by Masami Hiramatsu <mhiramat@redhat.com> # diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f744617c9946..c0e26ad1fa7e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -267,12 +267,13 @@ static int decode_instructions(struct objtool_file *file) &insn->immediate, &insn->stack_op); if (ret) - return ret; + goto err; if (!insn->type || insn->type > INSN_LAST) { WARN_FUNC("invalid instruction type %d", insn->sec, insn->offset, insn->type); - return -1; + ret = -1; + goto err; } hash_add(file->insn_hash, &insn->hash, insn->offset); @@ -296,6 +297,10 @@ static int decode_instructions(struct objtool_file *file) } return 0; + +err: + free(insn); + return ret; } /* @@ -1203,24 +1208,39 @@ static int update_insn_state(struct instruction *insn, struct insn_state *state) switch (op->src.type) { case OP_SRC_REG: - if (op->src.reg == CFI_SP && op->dest.reg == CFI_BP) { + if (op->src.reg == CFI_SP && op->dest.reg == CFI_BP && + cfa->base == CFI_SP && + regs[CFI_BP].base == CFI_CFA && + regs[CFI_BP].offset == -cfa->offset) { + + /* mov %rsp, %rbp */ + cfa->base = op->dest.reg; + state->bp_scratch = false; + } - if (cfa->base == CFI_SP && - regs[CFI_BP].base == CFI_CFA && - regs[CFI_BP].offset == -cfa->offset) { + else if (op->src.reg == CFI_SP && + op->dest.reg == CFI_BP && state->drap) { - /* mov %rsp, %rbp */ - cfa->base = op->dest.reg; - state->bp_scratch = false; - } + /* drap: mov %rsp, %rbp */ + regs[CFI_BP].base = CFI_BP; + regs[CFI_BP].offset = -state->stack_size; + state->bp_scratch = false; + } - else if (state->drap) { + else if (op->src.reg == CFI_SP && cfa->base == CFI_SP) { - /* drap: mov %rsp, %rbp */ - regs[CFI_BP].base = CFI_BP; - regs[CFI_BP].offset = -state->stack_size; - state->bp_scratch = false; - } + /* + * mov %rsp, %reg + * + * This is needed for the rare case where GCC + * does: + * + * mov %rsp, %rax + * ... + * mov %rax, %rsp + */ + state->vals[op->dest.reg].base = CFI_CFA; + state->vals[op->dest.reg].offset = -state->stack_size; } else if (op->dest.reg == cfa->base) { diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 6e9f980a7d26..24460155c82c 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -175,19 +175,20 @@ static int read_sections(struct elf *elf) return -1; } - sec->data = elf_getdata(s, NULL); - if (!sec->data) { - WARN_ELF("elf_getdata"); - return -1; - } - - if (sec->data->d_off != 0 || - sec->data->d_size != sec->sh.sh_size) { - WARN("unexpected data attributes for %s", sec->name); - return -1; + if (sec->sh.sh_size != 0) { + sec->data = elf_getdata(s, NULL); + if (!sec->data) { + WARN_ELF("elf_getdata"); + return -1; + } + if (sec->data->d_off != 0 || + sec->data->d_size != sec->sh.sh_size) { + WARN("unexpected data attributes for %s", + sec->name); + return -1; + } } - - sec->len = sec->data->d_size; + sec->len = sec->sh.sh_size; } /* sanity check, one more call to elf_nextscn() should return NULL */ @@ -508,6 +509,7 @@ struct section *elf_create_rela_section(struct elf *elf, struct section *base) strcat(relaname, base->name); sec = elf_create_section(elf, relaname, sizeof(GElf_Rela), 0); + free(relaname); if (!sec) return NULL; @@ -561,6 +563,7 @@ int elf_write(struct elf *elf) struct section *sec; Elf_Scn *s; + /* Update section headers for changed sections: */ list_for_each_entry(sec, &elf->sections, list) { if (sec->changed) { s = elf_getscn(elf->elf, sec->idx); @@ -568,13 +571,17 @@ int elf_write(struct elf *elf) WARN_ELF("elf_getscn"); return -1; } - if (!gelf_update_shdr (s, &sec->sh)) { + if (!gelf_update_shdr(s, &sec->sh)) { WARN_ELF("gelf_update_shdr"); return -1; } } } + /* Make sure the new section header entries get updated properly. */ + elf_flagelf(elf->elf, ELF_C_SET, ELF_F_DIRTY); + + /* Write all changes to the file. */ if (elf_update(elf->elf, ELF_C_WRITE) < 0) { WARN_ELF("elf_update"); return -1; |