diff mbox series

[RFA] fix leak in gdb_environ

Message ID 20221127182504.867308-1-philippe.waroquiers@skynet.be
State Committed
Commit c801f8f138c03cde994db597d11953c21ed892de
Headers
Series [RFA] fix leak in gdb_environ |

Commit Message

Philippe Waroquiers Nov. 27, 2022, 6:25 p.m. UTC 
  valgrind reports a leak when assigning a gdb_environ to another gdb_environ.
The memory allocated for the target gdb_environ env variables is not released.
The gdb_environ selftest reproduces the leak (see below).
Fix the leak by clearing the target gbd_environ before std::move-ing the
members.

Tested natively and re-running all tests under valgrind.

==3261873== 4,842 bytes in 69 blocks are definitely lost in loss record 6,772 of 6,839
==3261873==    at 0x483979B: malloc (vg_replace_malloc.c:393)
==3261873==    by 0x25A454: xmalloc (alloc.c:57)
==3261873==    by 0x7D1E4E: xstrdup (xstrdup.c:34)
==3261873==    by 0x7E2A51: gdb_environ::from_host_environ() (environ.cc:56)
==3261873==    by 0x66F1C8: test_reinit_from_host_environ (environ-selftests.c:78)
==3261873==    by 0x66F1C8: selftests::gdb_environ_tests::run_tests() (environ-selftests.c:285)
==3261873==    by 0x7EFC43: operator() (std_function.h:622)
=
---
 gdbsupport/environ.cc | 2 ++
 1 file changed, 2 insertions(+)

Comments

Simon Marchi Nov. 27, 2022, 6:41 p.m. UTC | #1 
On 11/27/22 13:25, Philippe Waroquiers via Gdb-patches wrote:
> valgrind reports a leak when assigning a gdb_environ to another gdb_environ.
> The memory allocated for the target gdb_environ env variables is not released.
> The gdb_environ selftest reproduces the leak (see below).
> Fix the leak by clearing the target gbd_environ before std::move-ing the

gbd_environ -> gdb_environ

Otherwise:

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon
Philippe Waroquiers Nov. 27, 2022, 8:16 p.m. UTC | #2 
On Sun, 2022-11-27 at 13:41 -0500, Simon Marchi wrote:
> 
> On 11/27/22 13:25, Philippe Waroquiers via Gdb-patches wrote:
> > valgrind reports a leak when assigning a gdb_environ to another gdb_environ.
> > The memory allocated for the target gdb_environ env variables is not released.
> > The gdb_environ selftest reproduces the leak (see below).
> > Fix the leak by clearing the target gbd_environ before std::move-ing the
> 
> gbd_environ -> gdb_environ
> 
> Otherwise:
> 
> Approved-By: Simon Marchi <simon.marchi@efficios.com>
Thanks for the review, pushed with the tag added.
diff mbox series

Patch

diff --git a/gdbsupport/environ.cc b/gdbsupport/environ.cc
index f5f6b38e19c..2d8e3ea6e92 100644
--- a/gdbsupport/environ.cc
+++ b/gdbsupport/environ.cc
@@ -29,6 +29,8 @@  gdb_environ::operator= (gdb_environ &&e)
   if (&e == this)
     return *this;
 
+  this->clear ();
+
   m_environ_vector = std::move (e.m_environ_vector);
   m_user_set_env = std::move (e.m_user_set_env);
   m_user_unset_env = std::move (e.m_user_unset_env);