From 66bdb2b07a1f50833ad79ea71a378dafd79030e6 Mon Sep 17 00:00:00 2001 From: notaz Date: Thu, 19 Mar 2015 03:41:02 +0200 Subject: [PATCH] translate: improve epilogue search, clear with and op --- tools/translate.c | 488 ++++++++++++++++++++++------------------------ 1 file changed, 229 insertions(+), 259 deletions(-) diff --git a/tools/translate.c b/tools/translate.c index a894f17..6c432dd 100644 --- a/tools/translate.c +++ b/tools/translate.c @@ -2862,20 +2862,170 @@ static void scan_for_call_type(int i, const struct parsed_opr *opr, } } -// early check for tail call or branch back -static int is_like_tailjmp(int j) +static void add_label_ref(struct label_ref *lr, int op_i) { - if (!(ops[j].flags & OPF_JMP)) - return 0; + struct label_ref *lr_new; - if (ops[j].op == OP_JMP && !ops[j].operand[0].had_ds) - // probably local branch back.. - return 1; - if (ops[j].op == OP_CALL) - // probably noreturn call.. - return 1; + if (lr->i == -1) { + lr->i = op_i; + return; + } - return 0; + lr_new = calloc(1, sizeof(*lr_new)); + lr_new->i = op_i; + lr_new->next = lr->next; + lr->next = lr_new; +} + +static struct parsed_data *try_resolve_jumptab(int i, int opcnt) +{ + struct parsed_op *po = &ops[i]; + struct parsed_data *pd; + char label[NAMELEN], *p; + int len, j, l; + + p = strchr(po->operand[0].name, '['); + if (p == NULL) + return NULL; + + len = p - po->operand[0].name; + strncpy(label, po->operand[0].name, len); + label[len] = 0; + + for (j = 0, pd = NULL; j < g_func_pd_cnt; j++) { + if (IS(g_func_pd[j].label, label)) { + pd = &g_func_pd[j]; + break; + } + } + if (pd == NULL) + //ferr(po, "label '%s' not parsed?\n", label); + return NULL; + + if (pd->type != OPT_OFFSET) + ferr(po, "label '%s' with non-offset data?\n", label); + + // find all labels, link + for (j = 0; j < pd->count; j++) { + for (l = 0; l < opcnt; l++) { + if (g_labels[l] != NULL && IS(g_labels[l], pd->d[j].u.label)) { + add_label_ref(&g_label_refs[l], i); + pd->d[j].bt_i = l; + break; + } + } + } + + return pd; +} + +static void clear_labels(int count) +{ + int i; + + for (i = 0; i < count; i++) { + if (g_labels[i] != NULL) { + free(g_labels[i]); + g_labels[i] = NULL; + } + } +} + +static void resolve_branches_parse_calls(int opcnt) +{ + const struct parsed_proto *pp_c; + struct parsed_proto *pp; + struct parsed_data *pd; + struct parsed_op *po; + const char *tmpname; + int i, l, ret; + + for (i = 0; i < opcnt; i++) + { + po = &ops[i]; + po->bt_i = -1; + po->btj = NULL; + + if (po->op == OP_CALL) { + pp = NULL; + + if (po->operand[0].type == OPT_LABEL) { + tmpname = opr_name(po, 0); + if (IS_START(tmpname, "loc_")) + ferr(po, "call to loc_*\n"); + pp_c = proto_parse(g_fhdr, tmpname, g_header_mode); + if (!g_header_mode && pp_c == NULL) + ferr(po, "proto_parse failed for call '%s'\n", tmpname); + + if (pp_c != NULL) { + pp = proto_clone(pp_c); + my_assert_not(pp, NULL); + } + } + else if (po->datap != NULL) { + pp = calloc(1, sizeof(*pp)); + my_assert_not(pp, NULL); + + ret = parse_protostr(po->datap, pp); + if (ret < 0) + ferr(po, "bad protostr supplied: %s\n", (char *)po->datap); + free(po->datap); + po->datap = NULL; + } + + if (pp != NULL) { + if (pp->is_fptr) + check_func_pp(po, pp, "fptr var call"); + if (pp->is_noreturn) + po->flags |= OPF_TAIL; + } + po->pp = pp; + continue; + } + + if (!(po->flags & OPF_JMP) || po->op == OP_RET) + continue; + + if (po->operand[0].type == OPT_REGMEM) { + pd = try_resolve_jumptab(i, opcnt); + if (pd == NULL) + goto tailcall; + + po->btj = pd; + continue; + } + + for (l = 0; l < opcnt; l++) { + if (g_labels[l] != NULL + && IS(po->operand[0].name, g_labels[l])) + { + if (l == i + 1 && po->op == OP_JMP) { + // yet another alignment type.. + po->flags |= OPF_RMD|OPF_DONE; + break; + } + add_label_ref(&g_label_refs[l], i); + po->bt_i = l; + break; + } + } + + if (po->bt_i != -1 || (po->flags & OPF_RMD)) + continue; + + if (po->operand[0].type == OPT_LABEL) + // assume tail call + goto tailcall; + + ferr(po, "unhandled branch\n"); + +tailcall: + po->op = OP_CALL; + po->flags |= OPF_TAIL; + if (i > 0 && ops[i - 1].op == OP_POP) + po->flags |= OPF_ATAIL; + i--; // reprocess + } } static void scan_prologue_epilogue(int opcnt) @@ -2925,12 +3075,13 @@ static void scan_prologue_epilogue(int opcnt) found = 0; do { for (; i < opcnt; i++) - if (ops[i].op == OP_RET) + if (ops[i].flags & OPF_TAIL) break; j = i - 1; if (i == opcnt && (ops[j].flags & OPF_JMP)) { - if (found && is_like_tailjmp(j)) - break; + if (ops[j].bt_i != -1 || ops[j].btj != NULL) + break; + i--; j--; } @@ -2939,6 +3090,14 @@ static void scan_prologue_epilogue(int opcnt) { ops[j].flags |= OPF_RMD | OPF_DONE; } + else if (ops[i].op == OP_CALL && ops[i].pp != NULL + && ops[i].pp->is_noreturn) + { + // on noreturn, msvc sometimes cleans stack, sometimes not + i++; + found = 1; + continue; + } else if (!(g_ida_func_attr & IDAFA_NORETURN)) ferr(&ops[j], "'pop ebp' expected\n"); @@ -2966,6 +3125,8 @@ static void scan_prologue_epilogue(int opcnt) i++; } while (i < opcnt); + if (!found) + ferr(ops, "missing ebp epilogue\n"); return; } @@ -3031,12 +3192,13 @@ static void scan_prologue_epilogue(int opcnt) i++; do { for (; i < opcnt; i++) - if (ops[i].op == OP_RET) + if (ops[i].flags & OPF_TAIL) break; j = i - 1; if (i == opcnt && (ops[j].flags & OPF_JMP)) { - if (found && is_like_tailjmp(j)) - break; + if (ops[j].bt_i != -1 || ops[j].btj != NULL) + break; + i--; j--; } @@ -3077,6 +3239,9 @@ static void scan_prologue_epilogue(int opcnt) i++; } while (i < opcnt); + + if (!found) + ferr(ops, "missing esp epilogue\n"); } } @@ -3808,75 +3973,6 @@ static void pp_insert_reg_arg(struct parsed_proto *pp, const char *reg) pp->argc_reg++; } -static void add_label_ref(struct label_ref *lr, int op_i) -{ - struct label_ref *lr_new; - - if (lr->i == -1) { - lr->i = op_i; - return; - } - - lr_new = calloc(1, sizeof(*lr_new)); - lr_new->i = op_i; - lr_new->next = lr->next; - lr->next = lr_new; -} - -static struct parsed_data *try_resolve_jumptab(int i, int opcnt) -{ - struct parsed_op *po = &ops[i]; - struct parsed_data *pd; - char label[NAMELEN], *p; - int len, j, l; - - p = strchr(po->operand[0].name, '['); - if (p == NULL) - return NULL; - - len = p - po->operand[0].name; - strncpy(label, po->operand[0].name, len); - label[len] = 0; - - for (j = 0, pd = NULL; j < g_func_pd_cnt; j++) { - if (IS(g_func_pd[j].label, label)) { - pd = &g_func_pd[j]; - break; - } - } - if (pd == NULL) - //ferr(po, "label '%s' not parsed?\n", label); - return NULL; - - if (pd->type != OPT_OFFSET) - ferr(po, "label '%s' with non-offset data?\n", label); - - // find all labels, link - for (j = 0; j < pd->count; j++) { - for (l = 0; l < opcnt; l++) { - if (g_labels[l] != NULL && IS(g_labels[l], pd->d[j].u.label)) { - add_label_ref(&g_label_refs[l], i); - pd->d[j].bt_i = l; - break; - } - } - } - - return pd; -} - -static void clear_labels(int count) -{ - int i; - - for (i = 0; i < count; i++) { - if (g_labels[i] != NULL) { - free(g_labels[i]); - g_labels[i] = NULL; - } - } -} - static void output_std_flags(FILE *fout, struct parsed_op *po, int *pfomask, const char *dst_opr_text) { @@ -3993,10 +4089,8 @@ static void gen_func(FILE *fout, FILE *fhdr, const char *funcn, int opcnt) struct parsed_op *po, *delayed_flag_op = NULL, *tmp_op; struct parsed_opr *last_arith_dst = NULL; char buf1[256], buf2[256], buf3[256], cast[64]; - const struct parsed_proto *pp_c; struct parsed_proto *pp, *pp_tmp; struct parsed_data *pd; - const char *tmpname; unsigned int uval; int save_arg_vars[MAX_ARG_GRP] = { 0, }; int cond_vars = 0; @@ -4029,110 +4123,28 @@ static void gen_func(FILE *fout, FILE *fhdr, const char *funcn, int opcnt) regmask_arg = get_pp_arg_regmask(g_func_pp); // pass1: - // - handle ebp/esp frame, remove ops related to it - scan_prologue_epilogue(opcnt); - - // pass2: - // - parse calls with labels // - resolve all branches - for (i = 0; i < opcnt; i++) - { - po = &ops[i]; - po->bt_i = -1; - po->btj = NULL; - - if (po->flags & (OPF_RMD|OPF_DONE)) - continue; - - if (po->op == OP_CALL) { - pp = NULL; - - if (po->operand[0].type == OPT_LABEL) { - tmpname = opr_name(po, 0); - if (IS_START(tmpname, "loc_")) - ferr(po, "call to loc_*\n"); - pp_c = proto_parse(fhdr, tmpname, 0); - if (pp_c == NULL) - ferr(po, "proto_parse failed for call '%s'\n", tmpname); - - pp = proto_clone(pp_c); - my_assert_not(pp, NULL); - } - else if (po->datap != NULL) { - pp = calloc(1, sizeof(*pp)); - my_assert_not(pp, NULL); - - ret = parse_protostr(po->datap, pp); - if (ret < 0) - ferr(po, "bad protostr supplied: %s\n", (char *)po->datap); - free(po->datap); - po->datap = NULL; - } - - if (pp != NULL) { - if (pp->is_fptr) - check_func_pp(po, pp, "fptr var call"); - if (pp->is_noreturn) - po->flags |= OPF_TAIL; - } - po->pp = pp; - continue; - } - - if (!(po->flags & OPF_JMP) || po->op == OP_RET) - continue; - - if (po->operand[0].type == OPT_REGMEM) { - pd = try_resolve_jumptab(i, opcnt); - if (pd == NULL) - goto tailcall; - - po->btj = pd; - continue; - } - - for (l = 0; l < opcnt; l++) { - if (g_labels[l] != NULL - && IS(po->operand[0].name, g_labels[l])) - { - if (l == i + 1 && po->op == OP_JMP) { - // yet another alignment type.. - po->flags |= OPF_RMD|OPF_DONE; - break; - } - add_label_ref(&g_label_refs[l], i); - po->bt_i = l; - break; - } - } - - if (po->bt_i != -1 || (po->flags & OPF_RMD)) - continue; - - if (po->operand[0].type == OPT_LABEL) - // assume tail call - goto tailcall; - - ferr(po, "unhandled branch\n"); + // - parse calls with labels + resolve_branches_parse_calls(opcnt); -tailcall: - po->op = OP_CALL; - po->flags |= OPF_TAIL; - if (i > 0 && ops[i - 1].op == OP_POP) - po->flags |= OPF_ATAIL; - i--; // reprocess - } + // pass2: + // - handle ebp/esp frame, remove ops related to it + scan_prologue_epilogue(opcnt); // pass3: // - remove dead labels - // - process trivial calls for (i = 0; i < opcnt; i++) { if (g_labels[i] != NULL && g_label_refs[i].i == -1) { free(g_labels[i]); g_labels[i] = NULL; } + } + // pass4: + // - process trivial calls + for (i = 0; i < opcnt; i++) + { po = &ops[i]; if (po->flags & (OPF_RMD|OPF_DONE)) continue; @@ -4165,7 +4177,7 @@ tailcall: } } - // pass4: + // pass5: // - process calls // - handle push /pop pairs for (i = 0; i < opcnt; i++) @@ -4192,7 +4204,7 @@ tailcall: scan_for_pop_const(i, opcnt, ®mask_pp); } - // pass5: + // pass6: // - find POPs for PUSHes, rm both // - scan for STD/CLD, propagate DF // - scan for all used registers @@ -4437,7 +4449,7 @@ tailcall: } } - // pass6: + // pass7: // - confirm regmask_save, it might have been reduced if (regmask_save != 0) { @@ -4969,6 +4981,19 @@ tailcall: // arithmetic w/flags case OP_AND: + if (po->operand[1].type == OPT_CONST && !po->operand[1].val) { + // deal with complex dst clear + assert_operand_cnt(2); + fprintf(fout, " %s = %s;", + out_dst_opr(buf1, sizeof(buf1), po, &po->operand[0]), + out_src_opr(buf2, sizeof(buf2), po, &po->operand[1], + default_cast_to(buf3, sizeof(buf3), &po->operand[0]), 0)); + output_std_flags(fout, po, &pfomask, buf1); + last_arith_dst = &po->operand[0]; + delayed_flag_op = NULL; + break; + } + // fallthrough case OP_OR: propagate_lmod(po, &po->operand[0], &po->operand[1]); // fallthrough @@ -5929,17 +5954,14 @@ static void gen_hdr(const char *funcn, int opcnt) { int save_arg_vars[MAX_ARG_GRP] = { 0, }; unsigned char cbits[MAX_OPS / 8]; - const struct parsed_proto *pp_c; struct parsed_proto *pp; struct func_prototype *fp; - struct parsed_data *pd; struct parsed_op *po; - const char *tmpname; int regmask_dummy = 0; int regmask_dep; int max_bp_offset = 0; int has_ret; - int i, j, l, ret; + int i, j, ret; if ((hg_fp_cnt & 0xff) == 0) { hg_fp = realloc(hg_fp, sizeof(hg_fp[0]) * (hg_fp_cnt + 0x100)); @@ -5967,89 +5989,37 @@ static void gen_hdr(const char *funcn, int opcnt) g_stack_frame_used = 0; // pass1: + // - resolve all branches + // - parse calls with labels + resolve_branches_parse_calls(opcnt); + + // pass2: // - handle ebp/esp frame, remove ops related to it scan_prologue_epilogue(opcnt); - // pass2: + // pass3: + // - remove dead labels // - collect calls - // - resolve all branches for (i = 0; i < opcnt; i++) { - po = &ops[i]; - po->bt_i = -1; - po->btj = NULL; + if (g_labels[i] != NULL && g_label_refs[i].i == -1) { + free(g_labels[i]); + g_labels[i] = NULL; + } + po = &ops[i]; if (po->flags & (OPF_RMD|OPF_DONE)) continue; if (po->op == OP_CALL) { - tmpname = opr_name(po, 0); - pp = NULL; - if (po->operand[0].type == OPT_LABEL) { - hg_fp_add_dep(fp, tmpname); - - // perhaps a call to already known func? - pp_c = proto_parse(g_fhdr, tmpname, 1); - if (pp_c != NULL) - pp = proto_clone(pp_c); - } - else if (po->datap != NULL) { - pp = calloc(1, sizeof(*pp)); - my_assert_not(pp, NULL); - - ret = parse_protostr(po->datap, pp); - if (ret < 0) - ferr(po, "bad protostr supplied: %s\n", (char *)po->datap); - free(po->datap); - po->datap = NULL; - } - if (pp != NULL && pp->is_noreturn) - po->flags |= OPF_TAIL; - - po->pp = pp; - continue; - } - - if (!(po->flags & OPF_JMP) || po->op == OP_RET) - continue; - - if (po->operand[0].type == OPT_REGMEM) { - pd = try_resolve_jumptab(i, opcnt); - if (pd == NULL) - goto tailcall; - - po->btj = pd; - continue; - } - - for (l = 0; l < opcnt; l++) { - if (g_labels[l] != NULL - && IS(po->operand[0].name, g_labels[l])) - { - add_label_ref(&g_label_refs[l], i); - po->bt_i = l; - break; - } + if (po->operand[0].type == OPT_LABEL) + hg_fp_add_dep(fp, opr_name(po, 0)); + else if (po->pp != NULL) + hg_fp_add_dep(fp, po->pp->name); } - - if (po->bt_i != -1 || (po->flags & OPF_RMD)) - continue; - - if (po->operand[0].type == OPT_LABEL) - // assume tail call - goto tailcall; - - ferr(po, "unhandled branch\n"); - -tailcall: - po->op = OP_CALL; - po->flags |= OPF_TAIL; - if (i > 0 && ops[i - 1].op == OP_POP) - po->flags |= OPF_ATAIL; - i--; // reprocess } - // pass3: + // pass4: // - remove dead labels // - handle push /pop pairs for (i = 0; i < opcnt; i++) @@ -6067,7 +6037,7 @@ tailcall: scan_for_pop_const(i, opcnt, ®mask_dummy); } - // pass4: + // pass5: // - process trivial calls for (i = 0; i < opcnt; i++) { @@ -6100,7 +6070,7 @@ tailcall: } } - // pass5: + // pass6: // - track saved regs (simple) // - process calls for (i = 0; i < opcnt; i++) @@ -6130,7 +6100,7 @@ tailcall: } } - // pass6 + // pass7 memset(cbits, 0, sizeof(cbits)); regmask_dep = 0; has_ret = -1; -- 2.39.2