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[patch] Fix corruption of non-C++ symbols by the demangler
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: elfutils-devel at lists dot fedorahosted dot org
- Date: Mon, 13 Jan 2014 23:17:18 +0100
- Subject: [patch] Fix corruption of non-C++ symbols by the demangler
Hi,
jankratochvil/demangle
for example currently plain symbol "f" (for function f()) gets printed in the
backtrace as "float" (as for a function float()).
libiberty/cp-demangle.c contains:
d_demangle_callback()
if (mangled[0] == '_' && mangled[1] == 'Z')
type = DCT_MANGLED;
else if (strncmp (mangled, "_GLOBAL_", 8) == 0
&& (mangled[8] == '.' || mangled[8] == '_' || mangled[8] == '$')
&& (mangled[9] == 'D' || mangled[9] == 'I')
&& mangled[10] == '_')
type = mangled[9] == 'I' ? DCT_GLOBAL_CTORS : DCT_GLOBAL_DTORS;
else
{
if ((options & DMGL_TYPES) == 0)
return 0;
type = DCT_TYPE;
}
I am not completely sure about DCT_GLOBAL_CTORS and DCT_GLOBAL_DTORS but I
could not find a compliant symbol without leading _Z for it.
DCT_TYPE is apparently inappropriate for the unwinder.
Thanks,
Jan
commit e1b6b9d3131f32ef54932388c814adc02ca6a329
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Mon Jan 13 23:04:03 2014 +0100
Fix corruption of non-C++ symbols by the demangler.
./
2014-01-13 Jan Kratochvil <jan.kratochvil@redhat.com>
* configure.ac: Add AC_PROG_CXX.
src/
2014-01-13 Jan Kratochvil <jan.kratochvil@redhat.com>
* stack.c (print_frames) <USE_DEMANGLE>: Check for _Z.
tests/
2014-01-13 Jan Kratochvil <jan.kratochvil@redhat.com>
* Makefile.am (check_PROGRAMS): Add backtrace-demangle.
(TESTS): Add run-backtrace-demangle.sh.
<!DEMANGLE>: Add ELFUTILS_DISABLE_DEMANGLE export.
(EXTRA_DIST): Add run-backtrace-demangle.sh
(backtrace_demangle_SOURCES): New.
* backtrace-demangle.cc: New file.
* run-backtrace-demangle.sh: New file.
Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>
diff --git a/configure.ac b/configure.ac
index 7bfa1da..0e4e0ba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -81,6 +81,7 @@ AS_IF([test "$enable_dwz" = no -a -d /usr/lib/debug/.dwz],
AH_TEMPLATE([ENABLE_DWZ], [Defined if libdw should support GNU ref_alt FORM, dwz multi files.])
AC_PROG_CC
+AC_PROG_CXX
AC_PROG_RANLIB
AC_PROG_YACC
AM_PROG_LEX
diff --git a/src/stack.c b/src/stack.c
index fdf4b07..275be08 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -1,5 +1,5 @@
/* Unwinding of frames like gstack/pstack.
- Copyright (C) 2013 Red Hat, Inc.
+ Copyright (C) 2013-2014 Red Hat, Inc.
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
@@ -220,7 +220,8 @@ print_frames (struct frames *frames, pid_t tid, int dwflerr, const char *what)
if (symname != NULL)
{
#ifdef USE_DEMANGLE
- if (! show_raw)
+ // Require GNU v3 ABI by the "_Z" prefix.
+ if (! show_raw && symname[0] == '_' && symname[1] == 'Z')
{
int status = -1;
char *dsymname = __cxa_demangle (symname, demangle_buffer,
diff --git a/tests/Makefile.am b/tests/Makefile.am
index eae64a8..f9fd18a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,6 +1,6 @@
## Process this file with automake to create Makefile.in
##
-## Copyright (C) 1996-2013 Red Hat, Inc.
+## Copyright (C) 1996-2014 Red Hat, Inc.
## This file is part of elfutils.
##
## This file is free software; you can redistribute it and/or modify
@@ -53,7 +53,7 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
alldts md5-sha1-test typeiter typeiter2 low_high_pc \
test-elf_cntl_gelf_getshdr dwflsyms dwfllines \
dwfl-report-elf-align varlocs backtrace backtrace-child \
- backtrace-data backtrace-dwarf
+ backtrace-data backtrace-dwarf backtrace-demangle
asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \
asm-tst6 asm-tst7 asm-tst8 asm-tst9
@@ -107,12 +107,17 @@ TESTS = run-arextract.sh run-arsymtest.sh newfile test-nlist \
run-backtrace-native-biarch.sh run-backtrace-native-core.sh \
run-backtrace-native-core-biarch.sh run-backtrace-core-x86_64.sh \
run-backtrace-core-i386.sh run-backtrace-core-ppc.sh \
- run-backtrace-core-s390x.sh run-backtrace-core-s390.sh
+ run-backtrace-core-s390x.sh run-backtrace-core-s390.sh \
+ run-backtrace-demangle.sh
if !BIARCH
export ELFUTILS_DISABLE_BIARCH = 1
endif
+if !DEMANGLE
+export ELFUTILS_DISABLE_DEMANGLE = 1
+endif
+
if !STANDALONE
check_PROGRAMS += msg_tst md5-sha1-test
TESTS += msg_tst md5-sha1-test
@@ -256,7 +261,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh \
run-backtrace-core-ppc.sh testfile66.bz2 testfile66.core.bz2 \
backtrace.s390x.core.bz2 backtrace.s390x.exec.bz2 \
backtrace.s390.core.bz2 backtrace.s390.exec.bz2 \
- run-backtrace-core-s390x.sh run-backtrace-core-s390.sh
+ run-backtrace-core-s390x.sh run-backtrace-core-s390.sh \
+ run-backtrace-demangle.sh
if USE_VALGRIND
valgrind_cmd='valgrind -q --error-exitcode=1 --run-libc-freeres=no'
@@ -393,6 +399,7 @@ backtrace_child_biarch_SOURCES = backtrace-child.c
backtrace_data_LDADD = $(libdw) $(libelf) $(libmudflap)
backtrace_dwarf_CFLAGS = -Wno-unused-parameter
backtrace_dwarf_LDADD = $(libdw) $(libelf) $(libmudflap)
+backtrace_demangle_SOURCES = backtrace-demangle.cc
if GCOV
check: check-am coverage
diff --git a/tests/backtrace-demangle.cc b/tests/backtrace-demangle.cc
new file mode 100644
index 0000000..5f9c075
--- /dev/null
+++ b/tests/backtrace-demangle.cc
@@ -0,0 +1,49 @@
+/* Test program for C++ demangled unwinding.
+ Copyright (C) 2014 Red Hat, Inc.
+ This file is part of elfutils.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ elfutils is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <unistd.h>
+
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+#define NOINLINE_NOCLONE __attribute__ ((noinline, noclone))
+#else
+#define NOINLINE_NOCLONE __attribute__ ((noinline))
+#endif
+
+static void NOINLINE_NOCLONE
+cxxfunc (int i)
+{
+ sleep (60);
+ // Avoid tail call optimization.
+ asm volatile ("");
+}
+
+extern "C"
+{
+ static void NOINLINE_NOCLONE
+ f (void)
+ {
+ cxxfunc(1);
+ // Avoid tail call optimization.
+ asm volatile ("");
+ }
+}
+
+int
+main()
+{
+ f();
+}
diff --git a/tests/run-backtrace-demangle.sh b/tests/run-backtrace-demangle.sh
new file mode 100755
index 0000000..aeb4eeb
--- /dev/null
+++ b/tests/run-backtrace-demangle.sh
@@ -0,0 +1,39 @@
+#! /bin/bash
+# Copyright (C) 2014 Red Hat, Inc.
+# This file is part of elfutils.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# elfutils is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+if test -n "$ELFUTILS_DISABLE_DEMANGLE"; then
+ exit 77
+fi
+
+. $srcdir/backtrace-subr.sh
+
+child=backtrace-demangle
+tempfiles $child.{bt,err}
+${abs_builddir}/$child & pid=$!
+sleep 1
+testrun ${abs_top_builddir}/src/stack -p $pid >$child.bt 2>$child.err
+kill -9 $pid
+cat $child.{bt,err}
+check_unsupported $child.err $child
+if ! grep -w f $child.bt; then
+ echo >&2 $2: no f
+ false
+fi
+if ! grep ' cxxfunc(int)' $child.bt; then
+ echo >&2 $2: no cxxfunc
+ false
+fi