diff options
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 81 |
1 files changed, 60 insertions, 21 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 3dffeb944523..f744617c9946 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -218,8 +218,10 @@ static void clear_insn_state(struct insn_state *state) memset(state, 0, sizeof(*state)); state->cfa.base = CFI_UNDEFINED; - for (i = 0; i < CFI_NUM_REGS; i++) + for (i = 0; i < CFI_NUM_REGS; i++) { state->regs[i].base = CFI_UNDEFINED; + state->vals[i].base = CFI_UNDEFINED; + } state->drap_reg = CFI_UNDEFINED; state->drap_offset = -1; } @@ -1201,24 +1203,47 @@ static int update_insn_state(struct instruction *insn, struct insn_state *state) switch (op->src.type) { case OP_SRC_REG: - if (cfa->base == op->src.reg && cfa->base == CFI_SP && - op->dest.reg == CFI_BP && regs[CFI_BP].base == CFI_CFA && - regs[CFI_BP].offset == -cfa->offset) { - - /* mov %rsp, %rbp */ - cfa->base = op->dest.reg; - state->bp_scratch = false; - } else if (state->drap) { - - /* drap: mov %rsp, %rbp */ - regs[CFI_BP].base = CFI_BP; - regs[CFI_BP].offset = -state->stack_size; - state->bp_scratch = false; - } else if (!no_fp) { - - WARN_FUNC("unknown stack-related register move", - insn->sec, insn->offset); - return -1; + if (op->src.reg == CFI_SP && op->dest.reg == CFI_BP) { + + if (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; + } + + else if (state->drap) { + + /* drap: mov %rsp, %rbp */ + regs[CFI_BP].base = CFI_BP; + regs[CFI_BP].offset = -state->stack_size; + state->bp_scratch = false; + } + } + + else if (op->dest.reg == cfa->base) { + + /* mov %reg, %rsp */ + if (cfa->base == CFI_SP && + state->vals[op->src.reg].base == CFI_CFA) { + + /* + * This is needed for the rare case + * where GCC does something dumb like: + * + * lea 0x8(%rsp), %rcx + * ... + * mov %rcx, %rsp + */ + cfa->offset = -state->vals[op->src.reg].offset; + state->stack_size = cfa->offset; + + } else { + cfa->base = CFI_UNDEFINED; + cfa->offset = 0; + } } break; @@ -1240,11 +1265,25 @@ static int update_insn_state(struct instruction *insn, struct insn_state *state) break; } - if (op->dest.reg != CFI_BP && op->src.reg == CFI_SP && - cfa->base == CFI_SP) { + if (op->src.reg == CFI_SP && cfa->base == CFI_SP) { /* drap: lea disp(%rsp), %drap */ state->drap_reg = op->dest.reg; + + /* + * lea disp(%rsp), %reg + * + * This is needed for the rare case where GCC + * does something dumb like: + * + * lea 0x8(%rsp), %rcx + * ... + * mov %rcx, %rsp + */ + state->vals[op->dest.reg].base = CFI_CFA; + state->vals[op->dest.reg].offset = \ + -state->stack_size + op->src.offset; + break; } |