Mercurial > hg > index.cgi
view lwasm/main.c @ 577:e49d24f4a9a5
Correct bug in the object file output code leading to stack corruption
It turns out leaving a pointer to a stack allocated temporary in a
persistent data structure is not conducive to correct program operation.
Undo the export check setup in the object file output sequence so a
pointer to stack allocated memory is not left hanging when the function
returns. This seems to correct at least one mysterious crash bug, and
possibly others.
Thanks to Boisy Pitre for reporting the crash bug that led to this
discovery, as well as a previous crash bug that likely has the same
root cause.
Additional thanks to Ciaran Anscomb whose debugger wielding wizardry
revealed the exact location of this particular bit of unbrilliance.
author | William Astle <lost@l-w.ca> |
---|---|
date | Sat, 03 Aug 2024 14:30:06 -0600 |
parents | ddc7b05a5675 |
children |
line wrap: on
line source
/* main.c Copyright © 2010 William Astle This file is part of LWTOOLS. LWTOOLS is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <lw_alloc.h> #include <lw_string.h> #include <lw_stringlist.h> #include <lw_expr.h> #include <lw_cmdline.h> #include "lwasm.h" #include "input.h" void lwasm_do_unicorns(asmstate_t *as); int parse_pragma_string(asmstate_t *as, char *str, int ignoreerr); /* command line option handling */ #define PROGVER "lwasm from " PACKAGE_STRING char *program_name; static struct lw_cmdline_options options[] = { { "output", 'o', "FILE", 0, "Output to FILE"}, { "debug", 'd', "LEVEL", lw_cmdline_opt_optional, "Set debug mode"}, { "format", 'f', "TYPE", 0, "Select output format: decb, basic, raw, obj, os9, ihex, srec, dragon, abs"}, { "list", 'l', "FILE", lw_cmdline_opt_optional, "Generate list [to FILE]"}, { "list-nofiles", 0x104, 0, 0, "Omit file names in list output"}, { "symbols", 's', 0, lw_cmdline_opt_optional, "Generate symbol list in listing, no effect without --list"}, { "symbols-nolocals", 0x103, 0, lw_cmdline_opt_optional, "Same as --symbols but with local labels ignored"}, { "symbol-dump", 0x106, "FILE", lw_cmdline_opt_optional, "Dump global symbol table in assembly format" }, { "tabs", 't', "WIDTH", 0, "Set tab spacing in listing (0=don't expand tabs)" }, { "map", 'm', "FILE", lw_cmdline_opt_optional, "Generate map [to FILE]"}, { "decb", 'b', 0, 0, "Generate DECB .bin format output, equivalent of --format=decb"}, { "dragon", 0x107, 0, 0, "Generate a Dragon DOS binary format, equivalent of --format=dragon"}, { "abs", 0x108, 0, 0, "Generate absolute binary format, equivalent of --format=abs"}, { "raw", 'r', 0, 0, "Generate raw binary format output, equivalent of --format=raw"}, { "obj", 0x100, 0, 0, "Generate proprietary object file format for later linking, equivalent of --format=obj" }, { "depend", 0x101, 0, 0, "Output a dependency list to stdout; do not do any actual output though assembly is completed as usual" }, { "dependnoerr", 0x102, 0, 0, "Output a dependency list to stdout; do not do any actual output though assembly is completed as usual; don't bail on missing include files" }, { "pragma", 'p', "PRAGMA", 0, "Set an assembler pragma to any value understood by the \"pragma\" pseudo op"}, { "6809", '9', 0, 0, "Set assembler to 6809 only mode" }, { "6309", '3', 0, 0, "Set assembler to 6309 mode (default)" }, { "includedir", 'I', "PATH", 0, "Add entry to include path" }, { "define", 'D', "SYM[=VAL]",0, "Automatically define SYM to be VAL (or 1)"}, { "preprocess", 'P', 0, 0, "Preprocess macros and conditionals and output revised source to stdout" }, { "unicorns", 0x142, 0, 0, "Add sooper sekrit sauce"}, { "6800compat", 0x200, 0, 0, "Enable 6800 compatibility instructions, equivalent to --pragma=6800compat" }, { "no-output", 0x105, 0, 0, "Inhibit creation of output file" }, { "no-warn", 0x109, "FLAG", 0, "Suppress warnings of the specified type" }, { 0 } }; static int parse_opts(int key, char *arg, void *state) { asmstate_t *as = state; switch (key) { case 'I': lw_stringlist_addstring(as -> include_list, arg); break; case 'D': { char *offs; int val = 1; lw_expr_t te; if ((offs = strchr(arg, '='))) { *offs = '\0'; val = strtol(offs + 1, NULL, 0); } /* register global symbol */ te = lw_expr_build(lw_expr_type_int, val); register_symbol(as, NULL, arg, te, symbol_flag_nocheck | symbol_flag_set); lw_expr_destroy(te); if (offs) *offs = '='; break; } case 'o': if (as -> output_file) lw_free(as -> output_file); as -> output_file = lw_strdup(arg); as -> flags &= ~FLAG_NOOUT; break; case 0x105: as -> flags |= FLAG_NOOUT; break; case 0x106: if (as -> symbol_dump_file) lw_free(as -> symbol_dump_file); if (!arg) as -> symbol_dump_file = lw_strdup("-"); else as -> symbol_dump_file = lw_strdup(arg); as -> flags |= FLAG_SYMDUMP; break; case 'd': #ifdef LWASM_NODEBUG fprintf(stderr, "This binary has been built without debugging message support\n"); #else if (!arg) as -> debug_level = 50; else as -> debug_level = atoi(arg); #endif break; case 't': if (arg) as -> tabwidth = atoi(arg); break; case 'l': if (as -> list_file) lw_free(as -> list_file); if (!arg) as -> list_file = lw_strdup("-"); else as -> list_file = lw_strdup(arg); as -> flags |= FLAG_LIST; break; case 'm': if (as -> map_file) lw_free(as -> map_file); if (!arg) as -> map_file = lw_strdup("-"); else as -> map_file = lw_strdup(arg); as -> flags |= FLAG_MAP; break; case 's': as -> flags |= FLAG_SYMBOLS; break; case 0x103: as -> flags |= FLAG_SYMBOLS | FLAG_SYMBOLS_NOLOCALS; break; case 0x104: as -> listnofile = 1; break; case 'b': as -> output_format = OUTPUT_DECB; break; case 0x107: as -> output_format = OUTPUT_DRAGON; break; case 0x108: as -> output_format = OUTPUT_ABS; break; case 'r': as -> output_format = OUTPUT_RAW; break; case 0x100: as -> output_format = OUTPUT_OBJ; break; case 0x101: as -> flags |= FLAG_DEPEND; break; case 0x102: as -> flags |= FLAG_DEPEND | FLAG_DEPENDNOERR; break; case 0x142: as -> flags |= FLAG_UNICORNS; break; case 'f': if (!strcasecmp(arg, "decb")) as -> output_format = OUTPUT_DECB; else if (!strcasecmp(arg, "basic")) as -> output_format = OUTPUT_BASIC; else if (!strcasecmp(arg, "raw")) as -> output_format = OUTPUT_RAW; else if (!strcasecmp(arg, "rawrel")) as -> output_format = OUTPUT_RAWREL; else if (!strcasecmp(arg, "obj")) as -> output_format = OUTPUT_OBJ; else if (!strcasecmp(arg, "srec")) as -> output_format = OUTPUT_SREC; else if (!strcasecmp(arg, "ihex")) as -> output_format = OUTPUT_IHEX; else if (!strcasecmp(arg, "hex")) as -> output_format = OUTPUT_HEX; else if (!strcasecmp(arg, "dragon")) as -> output_format = OUTPUT_DRAGON; else if (!strcasecmp(arg, "abs")) as -> output_format = OUTPUT_ABS; else if (!strcasecmp(arg, "os9")) { as -> pragmas |= PRAGMA_DOLLARNOTLOCAL; as -> output_format = OUTPUT_OS9; } else if (!strcasecmp(arg, "lwmod")) { as -> output_format = OUTPUT_LWMOD; } else { fprintf(stderr, "Invalid output format: %s\n", arg); exit(1); } break; case 'p': if (parse_pragma_string(as, arg, 0) == 0) { fprintf(stderr, "Unrecognized pragma string: %s\n", arg); exit(1); } break; case '9': as -> pragmas |= PRAGMA_6809; break; case '3': as -> pragmas &= ~PRAGMA_6809; break; case 'P': as -> preprocess = 1; break; case 0x109: if (!strcasecmp(arg, "ifp1") || !strcasecmp(arg, "ifp2")) as -> nowarn_flags |= NOWARN_IFP1; break; case 0x200: as -> pragmas |= PRAGMA_6800COMPAT; break; case lw_cmdline_key_end: break; case lw_cmdline_key_arg: lw_stringlist_addstring(as -> input_files, arg); break; default: return lw_cmdline_err_unknown; } return 0; } static struct lw_cmdline_parser cmdline_parser = { options, parse_opts, "INPUTFILE", "lwasm, a HD6309 and MC6809 cross-assembler\vPlease report bugs to lost@l-w.ca.", PROGVER }; /* main function; parse command line, set up assembler state, and run the assembler on the first file */ void do_pass1(asmstate_t *as); void do_pass2(asmstate_t *as); void do_pass3(asmstate_t *as); void do_pass4(asmstate_t *as); void do_pass5(asmstate_t *as); void do_pass6(asmstate_t *as); void do_pass7(asmstate_t *as); void do_output(asmstate_t *as); void do_symdump(asmstate_t *as); void do_list(asmstate_t *as); void do_map(asmstate_t *as); lw_expr_t lwasm_evaluate_special(int t, void *ptr, void *priv); lw_expr_t lwasm_evaluate_var(char *var, void *priv); lw_expr_t lwasm_parse_term(char **p, void *priv); void lwasm_dividezero(void *priv); struct passlist_s { char *passname; void (*fn)(asmstate_t *as); int fordep; } passlist[] = { { "parse", do_pass1, 1 }, { "symcheck", do_pass2 }, { "resolve1", do_pass3 }, { "resolve2", do_pass4 }, { "addressresolve", do_pass5 }, { "finalize", do_pass6 }, { "emit", do_pass7 }, { NULL, NULL } }; int main(int argc, char **argv) { int passnum; /* assembler state */ asmstate_t asmstate = { 0 }; program_name = argv[0]; lw_expr_set_special_handler(lwasm_evaluate_special); lw_expr_set_var_handler(lwasm_evaluate_var); lw_expr_set_term_parser(lwasm_parse_term); lw_expr_setdivzero(lwasm_dividezero); /* initialize assembler state */ asmstate.include_list = lw_stringlist_create(); asmstate.input_files = lw_stringlist_create(); asmstate.nextcontext = 1; asmstate.exprwidth = 16; asmstate.tabwidth = 8; // enable the "forward reference maximum size" pragma; old available // can be obtained with --pragma=noforwardrefmax asmstate.pragmas = PRAGMA_FORWARDREFMAX; /* parse command line arguments */ if (lw_cmdline_parse(&cmdline_parser, argc, argv, 0, 0, &asmstate) != 0) { exit(1); } if (!asmstate.output_file) { asmstate.output_file = lw_strdup("a.out"); } input_init(&asmstate); for (passnum = 0; passlist[passnum].fn; passnum++) { if ((asmstate.flags & FLAG_DEPEND) && passlist[passnum].fordep == 0) continue; asmstate.passno = passnum; debug_message(&asmstate, 50, "Doing pass %d (%s)\n", passnum, passlist[passnum].passname); (passlist[passnum].fn)(&asmstate); debug_message(&asmstate, 50, "After pass %d (%s)\n", passnum, passlist[passnum].passname); dump_state(&asmstate); if (asmstate.preprocess) { /* we're done if we were preprocessing */ exit(0); } if (asmstate.errorcount > 0) { if (asmstate.flags & FLAG_DEPEND) { // don't show errors during dependency scanning but // stop processing immediately break; } if (asmstate.flags & FLAG_UNICORNS) lwasm_do_unicorns(&asmstate); else lwasm_show_errors(&asmstate); exit(1); } } if (asmstate.flags & FLAG_DEPEND) { // output dependencies (other than "includebin") char *n; while ((n = lw_stack_pop(asmstate.includelist))) { fprintf(stdout, "%s\n", n); lw_free(n); } } else if ((asmstate.flags & FLAG_NOOUT) == 0) { debug_message(&asmstate, 50, "Doing output"); do_output(&asmstate); } debug_message(&asmstate, 50, "Done assembly"); if (asmstate.flags & FLAG_UNICORNS) { debug_message(&asmstate, 50, "Invoking unicorns"); lwasm_do_unicorns(&asmstate); } do_symdump(&asmstate); do_list(&asmstate); do_map(&asmstate); if (asmstate.testmode_errorcount > 0) exit(1); exit(0); }