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IABSD.fr/xenocara/xserver/os/backtrace.c
matthieu
- xserver/os/backtrace.c
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/* * Copyright 2008 Red Hat, Inc. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ #ifdef HAVE_DIX_CONFIG_H #include <dix-config.h> #endif #include "os.h" #include "misc.h" #include <errno.h> #include <string.h> #ifdef HAVE_LIBUNWIND #define UNW_LOCAL_ONLY #include <libunwind.h> #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include <dlfcn.h> void xorg_backtrace(void) { unw_cursor_t cursor; unw_context_t context; unw_word_t ip; unw_word_t off; unw_proc_info_t pip; int ret, i = 0; char procname[256]; const char *filename; Dl_info dlinfo; pip.unwind_info = NULL; ret = unw_getcontext(&context); if (ret) { ErrorFSigSafe("unw_getcontext failed: %s [%d]\n", unw_strerror(ret), ret); return; } ret = unw_init_local(&cursor, &context); if (ret) { ErrorFSigSafe("unw_init_local failed: %s [%d]\n", unw_strerror(ret), ret); return; } ErrorFSigSafe("\n"); ErrorFSigSafe("Backtrace:\n"); ret = unw_step(&cursor); while (ret > 0) { ret = unw_get_proc_info(&cursor, &pip); if (ret) { ErrorFSigSafe("unw_get_proc_info failed: %s [%d]\n", unw_strerror(ret), ret); break; } off = 0; ret = unw_get_proc_name(&cursor, procname, 256, &off); if (ret && ret != -UNW_ENOMEM) { if (ret != -UNW_EUNSPEC) ErrorFSigSafe("unw_get_proc_name failed: %s [%d]\n", unw_strerror(ret), ret); procname[0] = '?'; procname[1] = 0; } if (unw_get_reg (&cursor, UNW_REG_IP, &ip) < 0) ip = pip.start_ip + off; if (dladdr((void *)(uintptr_t)(ip), &dlinfo) && dlinfo.dli_fname && *dlinfo.dli_fname) filename = dlinfo.dli_fname; else filename = "?"; ErrorFSigSafe("%u: %s (%s%s+0x%x) [%p]\n", i++, filename, procname, ret == -UNW_ENOMEM ? "..." : "", (int)off, (void *)(uintptr_t)(ip)); ret = unw_step(&cursor); if (ret < 0) ErrorFSigSafe("unw_step failed: %s [%d]\n", unw_strerror(ret), ret); } ErrorFSigSafe("\n"); } #else /* HAVE_LIBUNWIND */ #ifdef HAVE_BACKTRACE #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include <dlfcn.h> #include <execinfo.h> void xorg_backtrace(void) { const int BT_SIZE = 64; void *array[BT_SIZE]; const char *mod; int size, i; Dl_info info; ErrorFSigSafe("\n"); ErrorFSigSafe("Backtrace:\n"); size = backtrace(array, BT_SIZE); for (i = 0; i < size; i++) { int rc = dladdr(array[i], &info); if (rc == 0) { ErrorFSigSafe("%u: ?? [%p]\n", i, array[i]); continue; } mod = (info.dli_fname && *info.dli_fname) ? info.dli_fname : "(vdso)"; if (info.dli_saddr) ErrorFSigSafe( "%u: %s (%s+0x%x) [%p]\n", i, mod, info.dli_sname, (unsigned int)((char *) array[i] - (char *) info.dli_saddr), array[i]); else ErrorFSigSafe( "%u: %s (%p+0x%x) [%p]\n", i, mod, info.dli_fbase, (unsigned int)((char *) array[i] - (char *) info.dli_fbase), array[i]); } ErrorFSigSafe("\n"); } #else /* not glibc or glibc < 2.1 */ #if defined(__sun) && defined(__SVR4) #define HAVE_PSTACK #endif #if defined(HAVE_WALKCONTEXT) /* Solaris 9 & later */ #include <ucontext.h> #include <signal.h> #include <dlfcn.h> #include <sys/elf.h> #ifdef _LP64 #define ElfSym Elf64_Sym #else #define ElfSym Elf32_Sym #endif /* Called for each frame on the stack to print its contents */ static int xorg_backtrace_frame(uintptr_t pc, int signo, void *arg) { Dl_info dlinfo; ElfSym *dlsym; char header[32]; int depth = *((int *) arg); if (signo) { char signame[SIG2STR_MAX]; if (sig2str(signo, signame) != 0) { strcpy(signame, "unknown"); } ErrorFSigSafe("** Signal %u (%s)\n", signo, signame); } snprintf(header, sizeof(header), "%d: 0x%lx", depth, pc); *((int *) arg) = depth + 1; /* Ask system dynamic loader for info on the address */ if (dladdr1((void *) pc, &dlinfo, (void **) &dlsym, RTLD_DL_SYMENT)) { unsigned long offset = pc - (uintptr_t) dlinfo.dli_saddr; const char *symname; if (offset < dlsym->st_size) { /* inside a function */ symname = dlinfo.dli_sname; } else { /* found which file it was in, but not which function */ symname = "<section start>"; offset = pc - (uintptr_t) dlinfo.dli_fbase; } ErrorFSigSafe("%s: %s:%s+0x%x\n", header, dlinfo.dli_fname, symname, offset); } else { /* Couldn't find symbol info from system dynamic loader, should * probably poke elfloader here, but haven't written that code yet, * so we just print the pc. */ ErrorFSigSafe("%s\n", header); } return 0; } #endif /* HAVE_WALKCONTEXT */ #ifdef HAVE_PSTACK #include <unistd.h> static int xorg_backtrace_pstack(void) { pid_t kidpid; int pipefd[2]; if (pipe(pipefd) != 0) { return -1; } kidpid = fork1(); if (kidpid == -1) { /* ERROR */ return -1; } else if (kidpid == 0) { /* CHILD */ char parent[16]; seteuid(0); close(STDIN_FILENO); close(STDOUT_FILENO); dup2(pipefd[1], STDOUT_FILENO); closefrom(STDERR_FILENO); snprintf(parent, sizeof(parent), "%d", getppid()); execle("/usr/bin/pstack", "pstack", parent, NULL); exit(1); } else { /* PARENT */ char btline[256]; int kidstat; int bytesread; int done = 0; close(pipefd[1]); while (!done) { bytesread = read(pipefd[0], btline, sizeof(btline) - 1); if (bytesread > 0) { btline[bytesread] = 0; ErrorFSigSafe("%s", btline); } else if ((bytesread < 0) || ((errno != EINTR) && (errno != EAGAIN))) done = 1; } close(pipefd[0]); waitpid(kidpid, &kidstat, 0); if (kidstat != 0) return -1; } return 0; } #endif /* HAVE_PSTACK */ #if defined(HAVE_PSTACK) || defined(HAVE_WALKCONTEXT) void xorg_backtrace(void) { ErrorFSigSafe("\n"); ErrorFSigSafe("Backtrace:\n"); #ifdef HAVE_PSTACK /* First try fork/exec of pstack - otherwise fall back to walkcontext pstack is preferred since it can print names of non-exported functions */ if (xorg_backtrace_pstack() < 0) #endif { #ifdef HAVE_WALKCONTEXT ucontext_t u; int depth = 1; if (getcontext(&u) == 0) walkcontext(&u, xorg_backtrace_frame, &depth); else #endif ErrorFSigSafe("Failed to get backtrace info: %s\n", strerror(errno)); } ErrorFSigSafe("\n"); } #else /* Default fallback if we can't find any way to get a backtrace */ void xorg_backtrace(void) { return; } #endif #endif #endif