On Tue, Feb 19, 2013 at 09:29:03PM +0100, Marcin Slusarz wrote: [...] > --- > From: Marcin Slusarz <marcin.slus...@gmail.com> > 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 <marcin.slus...@gmail.com> > --- > configure.ac | 7 +++++ > include/dix-config.h.in | 3 ++ > os/Makefile.am | 5 ++++ > os/backtrace.c | 75 > +++++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 90 insertions(+) > > diff --git a/configure.ac b/configure.ac > index 9415a54..4a292da 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -309,6 +309,13 @@ 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. > diff --git a/include/dix-config.h.in b/include/dix-config.h.in > index 578f249..5102263 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 <byteswap.h> 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 <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 > -- > 1.8.1
thanks for the changes but after applying this patch locally I do wonder: how did you test this? i'm getting undefined references to the various libunwind calls (_Ux86_64_getcontext, _Ux86_64_strerror,etc) for Xvfb, Xdmx, Xnext and all the tests). This needs some more polishing. Cheers, Peter _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel