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[PATCH 5/5] Fix memory leak in exception code
- From: Tom Tromey <tromey at adacore dot com>
- To: gdb-patches at sourceware dot org
- Cc: Tom Tromey <tromey at adacore dot com>
- Date: Thu, 25 Apr 2019 10:52:56 -0600
- Subject: [PATCH 5/5] Fix memory leak in exception code
- References: <20190425165256.31226-1-tromey@adacore.com>
PR gdb/24475 concerns a memory leak coming from gdb's exception
handling code.
The leak occurs because throw_exception_sjlj does not arrange to
destroy the exception object it is passed. However, because
gdb_exception has a destructor, it's undefined to longjmp in this
situation.
This patch fixes the problem by avoiding the need to run any
destructors in gdb_rl_callback_handler, by making the gdb_exception
"static".
gdb/ChangeLog
2019-04-25 Tom Tromey <tromey@adacore.com>
PR gdb/24475:
* event-top.c (gdb_rl_callback_handler): Make "gdb_rl_expt"
static.
---
gdb/ChangeLog | 6 ++++++
gdb/event-top.c | 6 +++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/gdb/event-top.c b/gdb/event-top.c
index 9fa46c8ad44..f4a7574741a 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -205,11 +205,15 @@ gdb_rl_callback_read_char_wrapper (gdb_client_data client_data)
static void
gdb_rl_callback_handler (char *rl) noexcept
{
- struct gdb_exception gdb_rl_expt;
+ /* This is static to avoid undefined behavior when calling
+ longjmp. */
+ static struct gdb_exception gdb_rl_expt;
struct ui *ui = current_ui;
try
{
+ /* Ensure the exception is reset on each call. */
+ gdb_rl_expt = {};
ui->input_handler (gdb::unique_xmalloc_ptr<char> (rl));
}
catch (gdb_exception &ex)
--
2.20.1