Commit e21e1830 authored by Marcin Ślusarz's avatar Marcin Ślusarz Committed by Peter Hutterer

os: use libunwind to generate backtraces

Libunwind generates backtraces much more reliably than glibc's "backtrace".

Before:
0: /opt/xserver/bin/X (0x400000+0x18ce36) [0x58ce36]
1: /opt/xserver/bin/X (xorg_backtrace+0x9) [0x58d119]
2: /opt/xserver/bin/X (0x400000+0x190d69) [0x590d69]
3: /lib64/libpthread.so.0 (0x7fb904268000+0x10a90) [0x7fb904278a90]
4: /lib64/libc.so.6 (ioctl+0x7) [0x7fb902fbf987]
5: /usr/lib64/libdrm.so.2 (drmIoctl+0x28) [0x7fb90405ffa8]
6: /usr/lib64/libdrm.so.2 (drmCommandWrite+0x1b) [0x7fb90406235b]
7: /usr/lib64/libdrm_nouveau.so.2 (nouveau_bo_wait+0x89) [0x7fb902009719]
8: /opt/xserver/lib/xorg/modules/drivers/nouveau_drv.so (0x7fb90220e000+0x76f3) [0x7fb9022156f3]
9: /opt/xserver/lib/xorg/modules/libexa.so (0x7fb9019c7000+0xbae0) [0x7fb9019d2ae0]
10: /opt/xserver/bin/X (0x400000+0x17d2b3) [0x57d2b3]
11: /opt/xserver/bin/X (0x400000+0xc9930) [0x4c9930]
12: /opt/xserver/bin/X (0x400000+0x3a81a) [0x43a81a]
13: /opt/xserver/bin/X (0x400000+0x3d6a1) [0x43d6a1]
14: /opt/xserver/bin/X (0x400000+0x2c2ca) [0x42c2ca]
15: /lib64/libc.so.6 (__libc_start_main+0xf5) [0x7fb902f019b5]
16: /opt/xserver/bin/X (0x400000+0x2c60d) [0x42c60d]
17: ?? [0x0]

After:
0: /opt/xserver/bin/X (OsSigHandler+0x39) [0x590d69]
1: /lib64/libpthread.so.0 (__restore_rt+0x0) [0x7fb904278a8f]
2: /lib64/libc.so.6 (ioctl+0x7) [0x7fb902fbf987]
3: /usr/lib64/libdrm.so.2 (drmIoctl+0x28) [0x7fb90405ffa8]
4: /usr/lib64/libdrm.so.2 (drmCommandWrite+0x1b) [0x7fb90406235b]
5: /usr/lib64/libdrm_nouveau.so.2 (nouveau_bo_wait+0x89) [0x7fb902009719]
6: /opt/xserver/lib/xorg/modules/drivers/nouveau_drv.so (nouveau_exa_download_from_screen+0x1a3) [0x7fb9022156f3]
7: /opt/xserver/lib/xorg/modules/libexa.so (exaGetImage+0x1f0) [0x7fb9019d2ae0]
8: /opt/xserver/bin/X (miSpriteGetImage+0x173) [0x57d2b3]
9: /opt/xserver/bin/X (compGetImage+0xb0) [0x4c9930]
10: /opt/xserver/bin/X (ProcGetImage+0x55a) [0x43a81a]
11: /opt/xserver/bin/X (Dispatch+0x341) [0x43d6a1]
12: /opt/xserver/bin/X (main+0x3ba) [0x42c2ca]
13: /lib64/libc.so.6 (__libc_start_main+0xf5) [0x7fb902f019b5]
14: /opt/xserver/bin/X (_start+0x29) [0x42c60d]
15: ? (?+0x29) [0x29]
Signed-off-by: Marcin Ślusarz's avatarMarcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Peter Hutterer's avatarPeter Hutterer <peter.hutterer@who-t.net>
Tested-by: default avatarKnut Petersen <knut.petersen@t-online.de>
parent e27b2e61
......@@ -308,6 +308,13 @@ AC_CHECK_HEADER([execinfo.h],[
])]
)
PKG_CHECK_MODULES(LIBUNWIND, libunwind, [HAVE_LIBUNWIND=yes], [HAVE_LIBUNWIND=no])
if test "x$HAVE_LIBUNWIND" = xyes; then
AC_DEFINE(HAVE_LIBUNWIND, 1, [Have libunwind support])
fi
AM_CONDITIONAL(HAVE_LIBUNWIND, [test "x$HAVE_LIBUNWIND" = xyes])
dnl ---------------------------------------------------------------------------
dnl Bus options and CPU capabilities. Replaces logic in
dnl hw/xfree86/os-support/bus/Makefile.am, among others.
......@@ -1336,7 +1343,7 @@ AC_DEFINE(BIGREQS, 1, [Support BigRequests extension])
if test "x$SPECIAL_DTRACE_OBJECTS" = "xyes" ; then
DIX_LIB='$(top_builddir)/dix/dix.O'
OS_LIB='$(top_builddir)/os/os.O $(SHA1_LIBS) $(DLOPEN_LIBS)'
OS_LIB='$(top_builddir)/os/os.O $(SHA1_LIBS) $(DLOPEN_LIBS) $(LIBUNWIND_LIBS)'
else
DIX_LIB='$(top_builddir)/dix/libdix.la'
OS_LIB='$(top_builddir)/os/libos.la'
......
......@@ -60,6 +60,9 @@
/* Has backtrace support */
#undef HAVE_BACKTRACE
/* Has libunwind support */
#undef HAVE_LIBUNWIND
/* Define to 1 if you have the <byteswap.h> header file. */
#undef HAVE_BYTESWAP_H
......
......@@ -34,6 +34,11 @@ if XDMCP
libos_la_SOURCES += $(XDMCP_SRCS)
endif
if HAVE_LIBUNWIND
AM_CFLAGS += $(LIBUNWIND_CFLAGS)
libos_la_LIBADD += $(LIBUNWIND_LIBS)
endif
EXTRA_DIST = $(SECURERPC_SRCS) $(XDMCP_SRCS)
if SPECIAL_DTRACE_OBJECTS
......
......@@ -30,6 +30,80 @@
#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 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;
}
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 (dladdr((void *)(pip.start_ip + off), &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 *)(pip.start_ip + off));
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
......@@ -246,3 +320,4 @@ xorg_backtrace(void)
#endif
#endif
#endif
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