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-rw-r--r--xorg-server/os/backtrace.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/xorg-server/os/backtrace.c b/xorg-server/os/backtrace.c
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+++ b/xorg-server/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
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * them 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 MERCHANTIBILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS 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"
+
+#ifdef HAVE_BACKTRACE
+#include <execinfo.h>
+
+void xorg_backtrace(void)
+{
+ void *array[32]; /* deeper nesting than this means something's wrong */
+ size_t size, i;
+ char **strings;
+ ErrorF("\nBacktrace:\n");
+ size = backtrace(array, 32);
+ strings = backtrace_symbols(array, size);
+ for (i = 0; i < size; i++)
+ ErrorF("%d: %s\n", i, strings[i]);
+ free(strings);
+}
+
+#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 it's 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");
+ }
+
+ ErrorF("** Signal %d (%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;
+ }
+ ErrorF("%s: %s:%s+0x%lx\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.
+ */
+ ErrorF("%s\n", header);
+ }
+
+ return 0;
+}
+# endif /* HAVE_WALKCONTEXT */
+
+# ifdef HAVE_PSTACK
+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;
+ ErrorF("%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) {
+
+ ErrorF("\nBacktrace:\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
+ Error("Failed to get backtrace info");
+ }
+ ErrorF("\n");
+}
+
+# else
+
+/* Default fallback if we can't find any way to get a backtrace */
+void xorg_backtrace(void) { return; }
+
+# endif
+#endif