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[PATCH][gdb/breakpoints] Fix sigsegv in info prog at exec catchpoint
- From: Tom de Vries <tdevries at suse dot de>
- To: gdb-patches at sourceware dot org
- Date: Fri, 20 Jul 2018 16:14:00 +0200
- Subject: [PATCH][gdb/breakpoints] Fix sigsegv in info prog at exec catchpoint
Hi,
with the test-case contained in this patch and compiled for debug we run into
a segfault with trunk gdb:
...
$ gdb catch-follow-exec -batch -ex "catch exec" \
-ex "set follow-exec-mode new" -ex "run" -ex "info prog"
Catchpoint 1 (exec)
process xxx is executing new program: /usr/bin/ls
[New inferior 2 (process 0)]
[New process xxx]
Thread 2.1 "ls" hit Catchpoint 1 (exec'd /usr/bin/ls), in _start () from
/lib64/ld-linux-x86-64.so.2
Segmentation fault (core dumped)
...
The patch fixes the segfault by returning an error in info_program_command
if get_last_target_status returns minus_one_ptid.
The test-case is non-standard, because the standard approach runs into
PR23020, a problem with gdb going to the background.
Build and reg-tested on x86_64-linux.
OK for trunk?
Thanks,
- Tom
[gdb/breakpoints] Fix sigsegv in info prog at exec catchpoint
2018-07-20 Tom de Vries <tdevries@suse.de>
PR breakpoints/23366
* infcmd.c (info_program_command): Handle ptid == minus_one_ptid.
* gdb.base/catch-follow-exec.c: New test.
* gdb.base/catch-follow-exec.exp: New file.
---
gdb/infcmd.c | 2 +-
gdb/testsuite/gdb.base/catch-follow-exec.c | 10 +++++
gdb/testsuite/gdb.base/catch-follow-exec.exp | 56 ++++++++++++++++++++++++++++
3 files changed, 67 insertions(+), 1 deletion(-)
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 821bcc6544..74d5956765 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -2091,7 +2091,7 @@ info_program_command (const char *args, int from_tty)
get_last_target_status (&ptid, &ws);
}
- if (ptid == null_ptid)
+ if (ptid == null_ptid || ptid == minus_one_ptid)
error (_("No selected thread."));
thread_info *tp = find_thread_ptid (ptid);
diff --git a/gdb/testsuite/gdb.base/catch-follow-exec.c b/gdb/testsuite/gdb.base/catch-follow-exec.c
new file mode 100644
index 0000000000..fa68a2a34e
--- /dev/null
+++ b/gdb/testsuite/gdb.base/catch-follow-exec.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+int
+main (void)
+{
+ char *exec_args[] = { "/bin/ls", "ppp", NULL };
+ execve (exec_args[0], exec_args, NULL);
+}
diff --git a/gdb/testsuite/gdb.base/catch-follow-exec.exp b/gdb/testsuite/gdb.base/catch-follow-exec.exp
new file mode 100644
index 0000000000..03611e9517
--- /dev/null
+++ b/gdb/testsuite/gdb.base/catch-follow-exec.exp
@@ -0,0 +1,56 @@
+# Copyright 2018 Free Software Foundation, Inc.
+
+# This program 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.
+#
+# This program 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/>.
+
+# Check whether finish respects the print pretty user setting when printing the
+# function result.
+
+standard_testfile
+
+if {[build_executable "failed to prepare" $testfile $srcfile debug] == -1} {
+ return -1
+}
+
+if { ![file exists /bin/bash] } {
+ unsupported "no bash"
+}
+
+if { ![file exists /bin/ls] } {
+ unsupported "no ls"
+}
+
+proc catch_follow_exec { } {
+ global binfile
+ global GDB
+
+ set test "catch-follow-exec"
+
+ append FLAGS " \"$binfile\""
+ append FLAGS " -batch"
+ append FLAGS " -ex \"catch exec\""
+ append FLAGS " -ex \"set follow-exec-mode new\""
+ append FLAGS " -ex \"run\""
+ append FLAGS " -ex \"info prog\""
+
+ catch {exec /bin/bash -c "$GDB $FLAGS"} catchlog
+ send_log "$catchlog\n"
+
+ if { [regexp {No selected thread} $catchlog] } {
+ pass $test
+ } else {
+ fail $test
+ }
+}
+
+catch_follow_exec