From e21e183059df5975e7086850d1931edb2c1bbd06 Mon Sep 17 00:00:00 2001 From: Marcin Slusarz Date: Thu, 21 Feb 2013 09:02:44 +1000 Subject: [PATCH] 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 Slusarz Reviewed-by: Peter Hutterer Tested-by: Knut Petersen --- configure.ac | 9 +++++- include/dix-config.h.in | 3 ++ os/Makefile.am | 5 ++++ os/backtrace.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 91 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 53335b1..8b9cbc9 100644 --- a/configure.ac +++ b/configure.ac @@ -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' diff --git a/include/dix-config.h.in b/include/dix-config.h.in index e1cb9eb..a643dfc 100644 --- a/include/dix-config.h.in +++ b/include/dix-config.h.in @@ -60,6 +60,9 @@ /* Has backtrace support */ #undef HAVE_BACKTRACE +/* Has libunwind support */ +#undef HAVE_LIBUNWIND + /* Define to 1 if you have the header file. */ #undef HAVE_BYTESWAP_H diff --git a/os/Makefile.am b/os/Makefile.am index 8891485..364b6da 100644 --- a/os/Makefile.am +++ b/os/Makefile.am @@ -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 diff --git a/os/backtrace.c b/os/backtrace.c index daac60c..426f9b1 100644 --- a/os/backtrace.c +++ b/os/backtrace.c @@ -30,6 +30,80 @@ #include #include +#ifdef HAVE_LIBUNWIND + +#define UNW_LOCAL_ONLY +#include + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include + +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 -- 1.8.1.4