Fix a crash in jit.c

Message ID 20181221185415.20964-1-tom@tromey.com
State New
Headers show
Series
  • Fix a crash in jit.c
Related show

Commit Message

Tom Tromey Dec. 21, 2018, 6:54 p.m.
A user at Mozilla pointed out a crash in jit.c.  In his situation, an
inferior using the JIT API exec'd an executable that did not use it.
This caused an assertion failure when jit.c:free_objfile_data called
delete_breakpoint with NULL.

This patch fixes the problem in the obvious way.  New test case
included.

gdb/ChangeLog
2018-12-21  Tom Tromey  <tom@tromey.com>

	* jit.c (free_objfile_data): Only delete breakpoint if non-null.

gdb/testsuite/ChangeLog
2018-12-21  Tom Tromey  <tom@tromey.com>

	* gdb.base/jit-exec.exp: New file.
	* gdb.base/jit-exec.c: New file.
	* gdb.base/jit-execd.c: New file.
---
 gdb/ChangeLog                       |  4 +++
 gdb/jit.c                           |  3 +-
 gdb/testsuite/ChangeLog             |  6 ++++
 gdb/testsuite/gdb.base/jit-exec.c   | 28 ++++++++++++++++++
 gdb/testsuite/gdb.base/jit-exec.exp | 46 +++++++++++++++++++++++++++++
 gdb/testsuite/gdb.base/jit-execd.c  | 22 ++++++++++++++
 6 files changed, 108 insertions(+), 1 deletion(-)
 create mode 100644 gdb/testsuite/gdb.base/jit-exec.c
 create mode 100644 gdb/testsuite/gdb.base/jit-exec.exp
 create mode 100644 gdb/testsuite/gdb.base/jit-execd.c

-- 
2.19.2

Comments

Simon Marchi Dec. 23, 2018, 3:20 p.m. | #1
On 2018-12-21 1:54 p.m., Tom Tromey wrote:
> A user at Mozilla pointed out a crash in jit.c.  In his situation, an

> inferior using the JIT API exec'd an executable that did not use it.

> This caused an assertion failure when jit.c:free_objfile_data called

> delete_breakpoint with NULL.

> 

> This patch fixes the problem in the obvious way.  New test case

> included.


The fix itself LGTM.  Using "run" in the test, however, makes it not work
with the native-gdbserver board.  Changing it to this works for me:


diff --git a/gdb/testsuite/gdb.base/jit-exec.exp b/gdb/testsuite/gdb.base/jit-exec.exp
index 74c6fa7a430f..514e01ffeaed 100644
--- a/gdb/testsuite/gdb.base/jit-exec.exp
+++ b/gdb/testsuite/gdb.base/jit-exec.exp
@@ -43,7 +43,10 @@ if {[gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" \

 clean_restart $binfile

-runto_main
-delete_breakpoints
+if ![runto_main] {
+    fail "can't run to main"
+    return
+}

+delete_breakpoints
 gdb_test "continue" "Inferior .* exited normally.*"


Simon
Tom Tromey Dec. 28, 2018, 9:07 p.m. | #2
>>>>> "Simon" == Simon Marchi <simark@simark.ca> writes:


Simon> The fix itself LGTM.  Using "run" in the test, however, makes it not work
Simon> with the native-gdbserver board.  Changing it to this works for me:

Thanks.  I'm checking it in with that change.

Tom

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 28ab3345032..8357344290e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@ 
+2018-12-21  Tom Tromey  <tom@tromey.com>
+
+	* jit.c (free_objfile_data): Only delete breakpoint if non-null.
+
 2018-12-19  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* gdb/dummy-frame.c (default_dummy_id): Defined new function.
diff --git a/gdb/jit.c b/gdb/jit.c
index e6b3cc25ca4..9ae5d4a908c 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -1464,7 +1464,8 @@  free_objfile_data (struct objfile *objfile, void *data)
       if (ps_data != NULL && ps_data->objfile == objfile)
 	{
 	  ps_data->objfile = NULL;
-	  delete_breakpoint (ps_data->jit_breakpoint);
+	  if (ps_data->jit_breakpoint != NULL)
+	    delete_breakpoint (ps_data->jit_breakpoint);
 	  ps_data->cached_code_address = 0;
 	}
     }
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index ab3a74fffd6..8c512ab564e 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@ 
+2018-12-21  Tom Tromey  <tom@tromey.com>
+
+	* gdb.base/jit-exec.exp: New file.
+	* gdb.base/jit-exec.c: New file.
+	* gdb.base/jit-execd.c: New file.
+
 2018-12-12  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* gdb.base/annota1.exp: Update a test regexp.
diff --git a/gdb/testsuite/gdb.base/jit-exec.c b/gdb/testsuite/gdb.base/jit-exec.c
new file mode 100644
index 00000000000..85b5334ee74
--- /dev/null
+++ b/gdb/testsuite/gdb.base/jit-exec.c
@@ -0,0 +1,28 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   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/>.  */
+
+/* Simple standalone program using the JIT API.  */
+
+#include "jit-simple-jit.c"
+#include <unistd.h>
+
+int
+main (int argc, char **argv)
+{
+  execl (PROGRAM, PROGRAM, (char *) 0);
+  return 99;
+}
diff --git a/gdb/testsuite/gdb.base/jit-exec.exp b/gdb/testsuite/gdb.base/jit-exec.exp
new file mode 100644
index 00000000000..0a4fce7b88d
--- /dev/null
+++ b/gdb/testsuite/gdb.base/jit-exec.exp
@@ -0,0 +1,46 @@ 
+# 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/>.
+
+# Regression test for a jit.c bug.  Previously it would crash if an
+# inferior that used the JIT API then exec'd a program that did not
+# use it.
+
+if { ![istarget "*-linux*"] } then {
+    return
+}
+
+standard_testfile jit-exec.c
+
+set testfile2 "jit-execd"
+set srcfile2 ${testfile2}.c
+set binfile2 [standard_output_file ${testfile2}]
+
+set compile_options [list debug additional_flags=-DPROGRAM=\"$binfile2\"]
+
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
+	 executable $compile_options] != ""} {
+    untested "failed to compile"
+    return -1
+}
+
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" \
+	 executable $compile_options] != ""} {
+    untested "failed to compile"
+    return -1
+}
+
+clean_restart $binfile
+
+gdb_test "run" "Inferior .* exited normally.*"
diff --git a/gdb/testsuite/gdb.base/jit-execd.c b/gdb/testsuite/gdb.base/jit-execd.c
new file mode 100644
index 00000000000..6afe539cb4b
--- /dev/null
+++ b/gdb/testsuite/gdb.base/jit-execd.c
@@ -0,0 +1,22 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   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/>.  */
+
+int
+main (int argc, char **argv)
+{
+  return 0;
+}