Fix corruption of non-C++ symbols by the demangler.

Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>

9 files changed, 127 insertions, 13 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d37cd1bb..50b6b588 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2014-01-15  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	Fix corruption of non-C++ symbols by the demangler.
+	* nm.c (show_symbols_sysv, show_symbols_bsd, show_symbols_posix)
+	(show_symbols): Check for _Z.
+	* stack.c (print_frames) <USE_DEMANGLE>: Check for _Z.
+
 2014-01-02  Mark Wielaard  <mjw@redhat.com>
 
 	* stack.c (show_raw): Declare unconditionally.
diff --git a/src/nm.c b/src/nm.c
index d434f44e..62efb2d0 100644
--- a/src/nm.c
+++ b/src/nm.c
@@ -820,8 +820,8 @@ show_symbols_sysv (Ebl *ebl, GElf_Word strndx, const char *fullname,
 				     symstrbuf, sizeof symstrbuf);
 
 #ifdef USE_DEMANGLE
-      /* Demangle if necessary.  */
-      if (demangle)
+      /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
+      if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
 	{
 	  int status = -1;
 	  char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
@@ -965,8 +965,8 @@ show_symbols_bsd (Elf *elf, const GElf_Ehdr *ehdr, GElf_Word strndx,
 	continue;
 
 #ifdef USE_DEMANGLE
-      /* Demangle if necessary.  */
-      if (demangle)
+      /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
+      if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
 	{
 	  int status = -1;
 	  char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
@@ -1076,8 +1076,8 @@ show_symbols_posix (Elf *elf, const GElf_Ehdr *ehdr, GElf_Word strndx,
 	continue;
 
 #ifdef USE_DEMANGLE
-      /* Demangle if necessary.  */
-      if (demangle)
+      /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
+      if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
 	{
 	  int status = -1;
 	  char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
@@ -1244,8 +1244,8 @@ show_symbols (Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn *scn, Elf_Scn *xndxscn,
 	    continue;
 
 #ifdef USE_DEMANGLE
-	  /* Demangle if necessary.  */
-	  if (demangle)
+	  /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
+	  if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
 	    {
 	      int status = -1;
 	      char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
diff --git a/src/stack.c b/src/stack.c
index fdf4b074..275be08c 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/ChangeLog b/tests/ChangeLog
index 7e9dcf4b..1b84f3a1 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,17 @@
+2014-01-15  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	Fix corruption of non-C++ symbols by the demangler.
+	* Makefile.am (TESTS): Add run-backtrace-demangle.sh.
+	<!DEMANGLE>: Add ELFUTILS_DISABLE_DEMANGLE export.
+	(EXTRA_DIST): Add run-backtrace-demangle.sh,
+	testfile-backtrace-demangle.bz2, testfile-backtrace-demangle.cc,
+	testfile-backtrace-demangle.core.bz2.
+	* backtrace-demangle.cc: New file.
+	* run-backtrace-demangle.sh: New file.
+	* testfile-backtrace-demangle.bz2: New file.
+	* testfile-backtrace-demangle.cc: New file.
+	* testfile-backtrace-demangle.core.bz2: New file.
+
 2014-01-07  Matthias Klose <doko@ubuntu.com>
 
 	* backtrace-subr.sh (check_native_core): Check to see if core file
diff --git a/tests/Makefile.am b/tests/Makefile.am
index eae64a83..1253574d 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
@@ -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 +261,10 @@ 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 testfile-backtrace-demangle.bz2 \
+	     testfile-backtrace-demangle.cc \
+	     testfile-backtrace-demangle.core.bz2
 
 if USE_VALGRIND
 valgrind_cmd='valgrind -q --error-exitcode=1 --run-libc-freeres=no'
diff --git a/tests/run-backtrace-demangle.sh b/tests/run-backtrace-demangle.sh
new file mode 100755
index 00000000..b5bddeb3
--- /dev/null
+++ b/tests/run-backtrace-demangle.sh
@@ -0,0 +1,37 @@
+#! /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
+set -x
+
+child=testfile-backtrace-demangle
+testfiles $child{,.core}
+tempfiles $child.{bt,err}
+testrun ${abs_top_builddir}/src/stack -e $child --core $child.core >$child.bt 2>$child.err
+cat $child.{bt,err}
+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
diff --git a/tests/testfile-backtrace-demangle.bz2 b/tests/testfile-backtrace-demangle.bz2
new file mode 100644
index 00000000..c3156e89
--- /dev/null
+++ b/tests/testfile-backtrace-demangle.bz2
diff --git a/tests/testfile-backtrace-demangle.cc b/tests/testfile-backtrace-demangle.cc
new file mode 100644
index 00000000..6daa4297
--- /dev/null
+++ b/tests/testfile-backtrace-demangle.cc
@@ -0,0 +1,47 @@
+/* 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/>.  */
+
+#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)
+{
+  *(volatile int *)0=0;
+  // 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/testfile-backtrace-demangle.core.bz2 b/tests/testfile-backtrace-demangle.core.bz2
new file mode 100644
index 00000000..c68edce1
--- /dev/null
+++ b/tests/testfile-backtrace-demangle.core.bz2