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[pushed] Fix Python unwinder frames regression
- From: Pedro Alves <palves at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Thu, 6 Jul 2017 00:51:11 +0100
- Subject: [pushed] Fix Python unwinder frames regression
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The gdb.python/py-unwind.exp test is crashing GDB / leaving core dumps
in the test dir, even though it all passes cleanly. The crash is not
visible in gdb.sum/gdb.log because it happens as side effect of the
"quit" command, while flushing the frame cache.
The problem is simply a typo in a 'for' loop's condition, introduced
by a recent change [4fa847d78edd ("Remove MAX_REGISTER_SIZE from
py-unwind.c")], resulting in infinite loop / double-free.
The new test exposes the crash, like:
Running src/gdb/testsuite/gdb.python/py-unwind.exp ...
ERROR: Process no longer exists
gdb/ChangeLog:
2017-07-06 Pedro Alves <palves@redhat.com>
* python/py-unwind.c (pyuw_dealloc_cache): Fix for loop condition.
gdb/testsuite/ChangeLog:
2017-07-06 Pedro Alves <palves@redhat.com>
* gdb.python/py-unwind.exp: Test flushregs.
---
gdb/ChangeLog | 4 ++++
gdb/testsuite/ChangeLog | 4 ++++
gdb/python/py-unwind.c | 2 +-
gdb/testsuite/gdb.python/py-unwind.exp | 3 ++-
4 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 03f30af..7908142 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2017-07-06 Pedro Alves <palves@redhat.com>
+
+ * python/py-unwind.c (pyuw_dealloc_cache): Fix for loop condition.
+
2017-07-04 Pedro Alves <palves@redhat.com>
* gdbtypes.c (recursive_dump_type): Don't reference TYPE_STATIC.
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 6160c4b..d6a7252 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2017-07-06 Pedro Alves <palves@redhat.com>
+
+ * gdb.python/py-unwind.exp: Test flushregs.
+
2017-06-30 Sergio Durigan Junior <sergiodj@redhat.com>
PR cli/21688
diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c
index 1d800a7..acfce7d 100644
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -595,7 +595,7 @@ pyuw_dealloc_cache (struct frame_info *this_frame, void *cache)
TRACE_PY_UNWIND (3, "%s: enter", __FUNCTION__);
cached_frame_info *cached_frame = (cached_frame_info *) cache;
- for (int i = 0; cached_frame->reg_count; i++)
+ for (int i = 0; i < cached_frame->reg_count; i++)
xfree (cached_frame->reg[i].data);
xfree (cache);
diff --git a/gdb/testsuite/gdb.python/py-unwind.exp b/gdb/testsuite/gdb.python/py-unwind.exp
index 0a4d34f..625b04c 100644
--- a/gdb/testsuite/gdb.python/py-unwind.exp
+++ b/gdb/testsuite/gdb.python/py-unwind.exp
@@ -51,4 +51,5 @@ gdb_test_sequence "where" "Backtrace restored by unwinder" {
"\\r\\n#2 .* main \\(.*\\) at"
}
-
+# Check that the Python unwinder frames can be flushed / released.
+gdb_test "flushregs" "Register cache flushed\\." "flush frames"
--
2.5.5