diff mbox

python: Fix memleak in do_start_initialization

Message ID 20171126035308.12274-1-simon.marchi@polymtl.ca
State New, archived
Headers

Commit Message

Simon Marchi Nov. 26, 2017, 3:53 a.m. UTC 
  While playing with valgrind, I noticed that the progname variable in
do_start_initialization is not being freed (concat returns a malloc'ed
string).  Use a unique_xmalloc_ptr to manage it.

gdb/ChangeLog:

	* python/python.c (do_start_initialization): Change progname
	type to gdb::unique_xmalloc_ptr.
---
 gdb/python/python.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Tom Tromey Nov. 26, 2017, 7 p.m. UTC | #1 
>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes:

Simon> While playing with valgrind, I noticed that the progname variable in
Simon> do_start_initialization is not being freed (concat returns a malloc'ed
Simon> string).  Use a unique_xmalloc_ptr to manage it.

I don't think this is quite correct.
On the Python 2 branch, the code does this:

  Py_SetProgramName (progname);

The docs for Py_SetProgramName say:

     The argument should point to a
     zero-terminated character string in static storage whose contents
     will not change for the duration of the program's execution.

I think a comment referring to the Python docs would be better.
And, freeing progname on the Python 3 branch is ok.
Maybe the Python 2 branch could pass "progname.release ()".

Tom
diff mbox

Patch

diff --git a/gdb/python/python.c b/gdb/python/python.c
index 5f152611e8..f17ac36569 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1658,7 +1658,7 @@  finalize_python (void *ignore)
 static bool
 do_start_initialization ()
 {
-  char *progname;
+  gdb::unique_xmalloc_ptr<char> progname;
 #ifdef IS_PY3K
   int i;
   size_t progsize, count;
@@ -1672,19 +1672,19 @@  do_start_initialization ()
      /foo/bin/python
      /foo/lib/pythonX.Y/...
      This must be done before calling Py_Initialize.  */
-  progname = concat (ldirname (python_libdir).c_str (), SLASH_STRING, "bin",
-		     SLASH_STRING, "python", (char *) NULL);
+  progname.reset (concat (ldirname (python_libdir).c_str (), SLASH_STRING,
+			  "bin", SLASH_STRING, "python", (char *) NULL));
 #ifdef IS_PY3K
   std::string oldloc = setlocale (LC_ALL, NULL);
   setlocale (LC_ALL, "");
-  progsize = strlen (progname);
+  progsize = strlen (progname.get ());
   progname_copy = (wchar_t *) PyMem_Malloc ((progsize + 1) * sizeof (wchar_t));
   if (!progname_copy)
     {
       fprintf (stderr, "out of memory\n");
       return false;
     }
-  count = mbstowcs (progname_copy, progname, progsize + 1);
+  count = mbstowcs (progname_copy, progname.get (), progsize + 1);
   if (count == (size_t) -1)
     {
       fprintf (stderr, "Could not convert python path to string\n");