Andres Lagar-Cavilla
2012-Sep-14 14:58 UTC
[PATCH] Fix libxenstore memory leak when USE_PTHREAD is not defined, V2
tools/xenstore/xs.c | 17 +++++++++++++----
1 files changed, 13 insertions(+), 4 deletions(-)
Redefine usage of pthread_cleanup_push and _pop, to explicitly call free for
heap objects in error paths.
By the way, set a suitable errno value for an error path that had none.
This is V2 after comments from Ian Campbell.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
diff -r 588d0dc298a4 -r a83fd69dcb27 tools/xenstore/xs.c
--- a/tools/xenstore/xs.c
+++ b/tools/xenstore/xs.c
@@ -110,6 +110,11 @@ struct xs_handle {
#define read_thread_exists(h) (h->read_thr_exists)
+/* Because pthread_cleanup_p* are not available when USE_PTHREAD is
+ * disabled, use these macros which convert appropriately. */
+#define cleanup_push_heap(p) cleanup_push(free, p)
+#define cleanup_pop_heap(run, p) cleanup_pop((run))
+
static void *read_thread(void *arg);
#else /* !defined(USE_PTHREAD) */
@@ -130,6 +135,9 @@ struct xs_handle {
#define cleanup_pop(run) ((void)0)
#define read_thread_exists(h) (0)
+#define cleanup_push_heap(p) ((void)0)
+#define cleanup_pop_heap(run, p) do { if ((run)) free(p); } while(0)
+
#endif
static int read_message(struct xs_handle *h, int nonblocking);
@@ -1059,7 +1067,7 @@ static int read_message(struct xs_handle
msg = malloc(sizeof(*msg));
if (msg == NULL)
goto error;
- cleanup_push(free, msg);
+ cleanup_push_heap(msg);
if (!read_all(h->fd, &msg->hdr, sizeof(msg->hdr), nonblocking)) {
/* Cancellation point */
saved_errno = errno;
goto error_freemsg;
@@ -1069,7 +1077,7 @@ static int read_message(struct xs_handle
body = msg->body = malloc(msg->hdr.len + 1);
if (body == NULL)
goto error_freemsg;
- cleanup_push(free, body);
+ cleanup_push_heap(body);
if (!read_all(h->fd, body, msg->hdr.len, 0)) { /* Cancellation point */
saved_errno = errno;
goto error_freebody;
@@ -1098,6 +1106,7 @@ static int read_message(struct xs_handle
/* There should only ever be one response pending! */
if (!list_empty(&h->reply_list)) {
mutex_unlock(&h->reply_mutex);
+ saved_errno = EEXIST;
goto error_freebody;
}
@@ -1110,9 +1119,9 @@ static int read_message(struct xs_handle
ret = 0;
error_freebody:
- cleanup_pop(ret == -1);
+ cleanup_pop_heap(ret == -1, body);
error_freemsg:
- cleanup_pop(ret == -1);
+ cleanup_pop_heap(ret == -1, msg);
error:
errno = saved_errno;
Ian Campbell
2012-Sep-14 15:10 UTC
Re: [PATCH] Fix libxenstore memory leak when USE_PTHREAD is not defined, V2
On Fri, 2012-09-14 at 15:58 +0100, Andres Lagar-Cavilla wrote:> tools/xenstore/xs.c | 17 +++++++++++++---- > 1 files changed, 13 insertions(+), 4 deletions(-) > > > Redefine usage of pthread_cleanup_push and _pop, to explicitly call free for > heap objects in error paths. > > By the way, set a suitable errno value for an error path that had none. > > This is V2 after comments from Ian Campbell. > > Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>Looks good to me Acked-by: Ian Campbell <ian.campbell@citrix.com>> > diff -r 588d0dc298a4 -r a83fd69dcb27 tools/xenstore/xs.c > --- a/tools/xenstore/xs.c > +++ b/tools/xenstore/xs.c > @@ -110,6 +110,11 @@ struct xs_handle { > > #define read_thread_exists(h) (h->read_thr_exists) > > +/* Because pthread_cleanup_p* are not available when USE_PTHREAD is > + * disabled, use these macros which convert appropriately. */ > +#define cleanup_push_heap(p) cleanup_push(free, p) > +#define cleanup_pop_heap(run, p) cleanup_pop((run)) > + > static void *read_thread(void *arg); > > #else /* !defined(USE_PTHREAD) */ > @@ -130,6 +135,9 @@ struct xs_handle { > #define cleanup_pop(run) ((void)0) > #define read_thread_exists(h) (0) > > +#define cleanup_push_heap(p) ((void)0) > +#define cleanup_pop_heap(run, p) do { if ((run)) free(p); } while(0) > + > #endif > > static int read_message(struct xs_handle *h, int nonblocking); > @@ -1059,7 +1067,7 @@ static int read_message(struct xs_handle > msg = malloc(sizeof(*msg)); > if (msg == NULL) > goto error; > - cleanup_push(free, msg); > + cleanup_push_heap(msg); > if (!read_all(h->fd, &msg->hdr, sizeof(msg->hdr), nonblocking)) { /* Cancellation point */ > saved_errno = errno; > goto error_freemsg; > @@ -1069,7 +1077,7 @@ static int read_message(struct xs_handle > body = msg->body = malloc(msg->hdr.len + 1); > if (body == NULL) > goto error_freemsg; > - cleanup_push(free, body); > + cleanup_push_heap(body); > if (!read_all(h->fd, body, msg->hdr.len, 0)) { /* Cancellation point */ > saved_errno = errno; > goto error_freebody; > @@ -1098,6 +1106,7 @@ static int read_message(struct xs_handle > /* There should only ever be one response pending! */ > if (!list_empty(&h->reply_list)) { > mutex_unlock(&h->reply_mutex); > + saved_errno = EEXIST; > goto error_freebody; > } > > @@ -1110,9 +1119,9 @@ static int read_message(struct xs_handle > ret = 0; > > error_freebody: > - cleanup_pop(ret == -1); > + cleanup_pop_heap(ret == -1, body); > error_freemsg: > - cleanup_pop(ret == -1); > + cleanup_pop_heap(ret == -1, msg); > error: > errno = saved_errno; >
Ian Campbell
2012-Sep-17 10:18 UTC
Re: [PATCH] Fix libxenstore memory leak when USE_PTHREAD is not defined, V2
On Fri, 2012-09-14 at 16:10 +0100, Ian Campbell wrote:> On Fri, 2012-09-14 at 15:58 +0100, Andres Lagar-Cavilla wrote: > > tools/xenstore/xs.c | 17 +++++++++++++---- > > 1 files changed, 13 insertions(+), 4 deletions(-) > > > > > > Redefine usage of pthread_cleanup_push and _pop, to explicitly call free for > > heap objects in error paths. > > > > By the way, set a suitable errno value for an error path that had none. > > > > This is V2 after comments from Ian Campbell. > > > > Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org> > > Looks good to me > > Acked-by: Ian Campbell <ian.campbell@citrix.com>and applied, thanks.