X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/0f5e8daaa6e9f74521068aa75837200bcd182ea6..3719170cd3de26a8fc027b9a6bb539a195b9e08c:/src/xbt/backtrace_linux.c diff --git a/src/xbt/backtrace_linux.c b/src/xbt/backtrace_linux.c index 29dd7f7a1a..04a26c714f 100644 --- a/src/xbt/backtrace_linux.c +++ b/src/xbt/backtrace_linux.c @@ -25,13 +25,69 @@ void xbt_backtrace_postexit(void) { } +#include +struct trace_arg { + void **array; + int cnt, size; +}; + +static _Unwind_Reason_Code +backtrace_helper (struct _Unwind_Context *ctx, void *a) +{ + struct trace_arg *arg = a; + + /* We are first called with address in the __backtrace function. + Skip it. */ + if (arg->cnt != -1) + { + arg->array[arg->cnt] = (void *) _Unwind_GetIP(ctx); + + /* Check whether we make any progress. */ + if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt]) + return _URC_END_OF_STACK; + } + if (++arg->cnt == arg->size) + return _URC_END_OF_STACK; + return _URC_NO_REASON; +} + +/** @brief reimplementation of glibc backtrace based directly on gcc library, without implicit malloc + * + * See http://webloria.loria.fr/~quinson/blog/2012/0208/system_programming_fun_in_SimGrid/ + * for the motivation behind this function + * */ + +int xbt_backtrace_no_malloc(void **array, int size) { + + int i = 0; + for(i=0; i < size; i++) + array[i] = NULL; + + struct trace_arg arg = { .array = array, .size = size, .cnt = -1 }; + + if (size >= 1) + _Unwind_Backtrace(backtrace_helper, &arg); + + /* _Unwind_Backtrace on IA-64 seems to put NULL address above + _start. Fix it up here. */ + if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL) + --arg.cnt; + return arg.cnt != -1 ? arg.cnt : 0; +} + void xbt_backtrace_current(xbt_ex_t * e) { e->used = backtrace((void **) e->bt, XBT_BACKTRACE_SIZE); + if (e->used == 0) { + fprintf(stderr, "The backtrace() function failed, which probably means that the memory is exhausted. Here is a crude dump of the exception that I was trying to build:"); + fprintf(stderr, "%s:%s(%d) [%s:%d] %s", e->host,e->procname,e->pid, e->file,e->line,e->msg); + fprintf(stderr, "Bailing out now since there is nothing I can do without a decent amount of memory. Please go fix the memleaks\n"); + exit(1); + } } -void xbt_ex_setup_backtrace(xbt_ex_t * e) +void xbt_ex_setup_backtrace(xbt_ex_t * e) //FIXME: This code could be greatly improved/simplifyied with http://cairo.sourcearchive.com/documentation/1.9.4/backtrace-symbols_8c-source.html { int i; @@ -43,7 +99,7 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) /* to extract the addresses from the backtrace */ char **addrs; - char buff[256], *p; + char buff[256]; /* To read the output of addr2line */ FILE *pipe; @@ -56,27 +112,25 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) struct stat stat_buf; char *binary_name = NULL; - xbt_assert0(e - && e->used, - "Backtrace not setup yet, cannot set it up for display"); - - backtrace_syms = backtrace_symbols(e->bt, e->used); - /* ignore first one, which is this xbt_backtrace_current() */ - e->used--; - memmove(backtrace_syms, backtrace_syms + 1, sizeof(char *) * e->used); - addrs = xbt_new(char *, e->used); + xbt_assert(e, "Backtrace not setup yet, cannot set it up for display"); e->bt_strings = NULL; - /* Some arches only have stubs of backtrace, no implementation (hppa comes to mind) */ - if (!e->used) + if (xbt_binary_name == NULL) /* no binary name, nothing to do */ + return; + + if (e->used <= 1) return; + /* ignore first one, which is xbt_backtrace_current() */ + e->used--; + memmove(e->bt, e->bt + 1, (sizeof *e->bt) * e->used); + + backtrace_syms = backtrace_symbols(e->bt, e->used); + /* build the commandline */ if (stat(xbt_binary_name, &stat_buf)) { /* Damn. binary not in current dir. We'll have to dig the PATH to find it */ - int i; - for (i = 0; environ[i]; i++) { if (!strncmp("PATH=", environ[i], 5)) { xbt_dynar_t path = xbt_str_split(environ[i] + 5, ":"); @@ -84,27 +138,26 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) char *data; xbt_dynar_foreach(path, cpt, data) { - if (binary_name) - free(binary_name); + free(binary_name); binary_name = bprintf("%s/%s", data, xbt_binary_name); if (!stat(binary_name, &stat_buf)) { /* Found. */ - DEBUG1("Looked in the PATH for the binary. Found %s", + XBT_DEBUG("Looked in the PATH for the binary. Found %s", binary_name); - xbt_dynar_free(&path); break; } } + xbt_dynar_free(&path); if (stat(binary_name, &stat_buf)) { /* not found */ e->used = 1; e->bt_strings = xbt_new(char *, 1); e->bt_strings[0] = - bprintf("(binary '%s' not found the path)", xbt_binary_name); + bprintf("(binary '%s' not found in the PATH)", xbt_binary_name); + free(backtrace_syms); return; } - xbt_dynar_free(&path); break; } } @@ -118,17 +171,19 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) curr += sprintf(curr, "%s -f -e %s ", ADDR2LINE, binary_name); free(binary_name); + addrs = xbt_new(char *, e->used); for (i = 0; i < e->used; i++) { + char *p; /* retrieve this address */ - DEBUG2("Retrieving address number %d from '%s'", i, backtrace_syms[i]); + XBT_DEBUG("Retrieving address number %d from '%s'", i, backtrace_syms[i]); snprintf(buff, 256, "%s", strchr(backtrace_syms[i], '[') + 1); p = strchr(buff, ']'); *p = '\0'; if (strcmp(buff, "(nil)")) - addrs[i] = bprintf("%s", buff); + addrs[i] = xbt_strdup(buff); else - addrs[i] = bprintf("0x0"); - DEBUG3("Set up a new address: %d, '%s'(%p)", i, addrs[i], addrs[i]); + addrs[i] = xbt_strdup("0x0"); + XBT_DEBUG("Set up a new address: %d, '%s'(%p)", i, addrs[i], addrs[i]); /* Add it to the command line args */ curr += sprintf(curr, "%s ", addrs[i]); @@ -138,31 +193,29 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) /* parse the output and build a new backtrace */ e->bt_strings = xbt_new(char *, e->used); - VERB1("Fire a first command: '%s'", cmd); + XBT_VERB("Fire a first command: '%s'", cmd); pipe = popen(cmd, "r"); if (!pipe) { - CRITICAL0("Cannot fork addr2line to display the backtrace"); - abort(); + xbt_die("Cannot fork addr2line to display the backtrace"); } for (i = 0; i < e->used; i++) { - char *fgets_res; - DEBUG2("Looking for symbol %d, addr = '%s'", i, addrs[i]); - fgets_res = fgets(line_func, 1024, pipe); - if (fgets_res == NULL) - THROW2(system_error, 0, - "Cannot run fgets to look for symbol %d, addr %s", i, - addrs[i]); - line_func[strlen(line_func) - 1] = '\0'; - fgets_res = fgets(line_pos, 1024, pipe); - if (fgets_res == NULL) - THROW2(system_error, 0, - "Cannot run fgets to look for symbol %d, addr %s", i, - addrs[i]); - line_pos[strlen(line_pos) - 1] = '\0'; - - if (strcmp("??", line_func)) { - DEBUG2("Found static symbol %s() at %s", line_func, line_pos); + XBT_DEBUG("Looking for symbol %d, addr = '%s'", i, addrs[i]); + if (fgets(line_func, 1024, pipe)) { + line_func[strlen(line_func) - 1] = '\0'; + } else { + XBT_VERB("Cannot run fgets to look for symbol %d, addr %s", i, addrs[i]); + strcpy(line_func, "???"); + } + if (fgets(line_pos, 1024, pipe)) { + line_pos[strlen(line_pos) - 1] = '\0'; + } else { + XBT_VERB("Cannot run fgets to look for symbol %d, addr %s", i, addrs[i]); + strcpy(line_pos, backtrace_syms[i]); + } + + if (strcmp("??", line_func) != 0) { + XBT_DEBUG("Found static symbol %s() at %s", line_func, line_pos); e->bt_strings[i] = bprintf("** In %s() at %s", line_func, line_pos); } else { @@ -182,14 +235,12 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) maps_name = bprintf("/proc/%d/maps", (int) getpid()); maps = fopen(maps_name, "r"); - sscanf(addrs[i], "%lx", &addr); - sprintf(maps_buff, "%#lx", addr); - - if (strcmp(addrs[i], maps_buff)) { - CRITICAL2("Cannot parse backtrace address '%s' (addr=%#lx)", + addr = strtol(addrs[i], &p, 16); + if (*p != '\0') { + XBT_CRITICAL("Cannot parse backtrace address '%s' (addr=%#lx)", addrs[i], addr); } - DEBUG2("addr=%s (as string) =%#lx (as number)", addrs[i], addr); + XBT_DEBUG("addr=%s (as string) =%#lx (as number)", addrs[i], addr); while (!found) { long int first, last; @@ -198,7 +249,7 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) break; if (i == 0) { maps_buff[strlen(maps_buff) - 1] = '\0'; - DEBUG1("map line: %s", maps_buff); + XBT_DEBUG("map line: %s", maps_buff); } sscanf(maps_buff, "%lx", &first); p = strchr(maps_buff, '-') + 1; @@ -208,18 +259,19 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) found = 1; } if (found) { - DEBUG3("%#lx in [%#lx-%#lx]", addr, first, last); - DEBUG0 + XBT_DEBUG("%#lx in [%#lx-%#lx]", addr, first, last); + XBT_DEBUG ("Symbol found, map lines not further displayed (even if looking for next ones)"); } } fclose(maps); free(maps_name); + free(addrs[i]); if (!found) { - VERB0 + XBT_VERB ("Problem while reading the maps file. Following backtrace will be mangled."); - DEBUG1("No dynamic. Static symbol: %s", backtrace_syms[i]); + XBT_DEBUG("No dynamic. Static symbol: %s", backtrace_syms[i]); e->bt_strings[i] = bprintf("** In ?? (%s)", backtrace_syms[i]); continue; } @@ -228,9 +280,8 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) We now need to substract this from the address we got from backtrace. */ - free(addrs[i]); addrs[i] = bprintf("0x%0*lx", addr_len - 2, addr - offset); - DEBUG2("offset=%#lx new addr=%s", offset, addrs[i]); + XBT_DEBUG("offset=%#lx new addr=%s", offset, addrs[i]); /* Got it. We have our new address. Let's get the library path and we are set */ @@ -250,34 +301,35 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) /* Here we go, fire an addr2line up */ subcmd = bprintf("%s -f -e %s %s", ADDR2LINE, p, addrs[i]); free(p); - VERB1("Fire a new command: '%s'", subcmd); + XBT_VERB("Fire a new command: '%s'", subcmd); subpipe = popen(subcmd, "r"); if (!subpipe) { - CRITICAL0("Cannot fork addr2line to display the backtrace"); - abort(); + xbt_die("Cannot fork addr2line to display the backtrace"); + } + if (fgets(line_func, 1024, subpipe)) { + line_func[strlen(line_func) - 1] = '\0'; + } else { + XBT_VERB("Cannot read result of subcommand %s", subcmd); + strcpy(line_func, "???"); + } + if (fgets(line_pos, 1024, subpipe)) { + line_pos[strlen(line_pos) - 1] = '\0'; + } else { + XBT_VERB("Cannot read result of subcommand %s", subcmd); + strcpy(line_pos, backtrace_syms[i]); } - fgets_res = fgets(line_func, 1024, subpipe); - if (fgets_res == NULL) - THROW1(system_error, 0, "Cannot read result of subcommand %s", - subcmd); - line_func[strlen(line_func) - 1] = '\0'; - fgets_res = fgets(line_pos, 1024, subpipe); - if (fgets_res == NULL) - THROW1(system_error, 0, "Cannot read result of subcommand %s", - subcmd); - line_pos[strlen(line_pos) - 1] = '\0'; pclose(subpipe); free(subcmd); } /* check whether the trick worked */ if (strcmp("??", line_func)) { - DEBUG2("Found dynamic symbol %s() at %s", line_func, line_pos); + XBT_DEBUG("Found dynamic symbol %s() at %s", line_func, line_pos); e->bt_strings[i] = bprintf("** In %s() at %s", line_func, line_pos); } else { /* damn, nothing to do here. Let's print the raw address */ - DEBUG1("Dynamic symbol not found. Raw address = %s", + XBT_DEBUG("Dynamic symbol not found. Raw address = %s", backtrace_syms[i]); e->bt_strings[i] = bprintf("** In ?? at %s", backtrace_syms[i]); } @@ -295,13 +347,13 @@ void xbt_ex_setup_backtrace(xbt_ex_t * e) for (j = i + 1; j < e->used; j++) free(addrs[j]); - e->used = i; + e->used = i + 1; if (!strncmp ("xbt_thread_context_wrapper", line_func, strlen("xbt_thread_context_wrapper"))) { - e->used++; - e->bt_strings[i] = bprintf("** (in a separate thread)"); + free(e->bt_strings[i]); + e->bt_strings[i] = xbt_strdup("** (in a separate thread)"); } }