qemu/hw/display/virtio-dmabuf.c
Matheus Tavares Bernardino 9b50fd0290 hw/display: fix memleak from virtio_add_resource
When the given uuid is already present in the hash table,
virtio_add_resource() does not add the passed VirtioSharedObject. In
this case, free it in the callers to avoid leaking memory. This fixed
the following `make check` error, when built with --enable-sanitizers:

  4/166 qemu:unit / test-virtio-dmabuf   ERROR 1.51s   exit status 1

  ==7716==ERROR: LeakSanitizer: detected memory leaks
  Direct leak of 320 byte(s) in 20 object(s) allocated from:
      #0 0x7f6fc16e3808 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:144
      #1 0x7f6fc1503e98 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x57e98)
      #2 0x564d63cafb6b in test_add_invalid_resource ../tests/unit/test-virtio-dmabuf.c:100
      #3 0x7f6fc152659d  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a59d)
  SUMMARY: AddressSanitizer: 320 byte(s) leaked in 20 allocation(s).

The changes at virtio_add_resource() itself are not strictly necessary
for the memleak fix, but they make it more obvious that, on an error
return, the passed object is not added to the hash.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Message-Id: <c61c13f9a0c67dec473bdbfc8789c29ef26c900b.1696624734.git.quic_mathbern@quicinc.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Albert Esteve <aesteve@redhat.com>
Signed-off-by: Matheus Tavares Bernardino &lt;<a href="mailto:quic_mathbern@quicinc.com" target="_blank">quic_mathbern@quicinc.com</a>&gt;<br>
2023-10-22 05:18:16 -04:00

147 lines
3.3 KiB
C

/*
* Virtio Shared dma-buf
*
* Copyright Red Hat, Inc. 2023
*
* Authors:
* Albert Esteve <aesteve@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "hw/virtio/virtio-dmabuf.h"
static GMutex lock;
static GHashTable *resource_uuids;
/*
* uuid_equal_func: wrapper for UUID is_equal function to
* satisfy g_hash_table_new expected parameters signatures.
*/
static int uuid_equal_func(const void *lhv, const void *rhv)
{
return qemu_uuid_is_equal(lhv, rhv);
}
static bool virtio_add_resource(QemuUUID *uuid, VirtioSharedObject *value)
{
bool result = true;
g_mutex_lock(&lock);
if (resource_uuids == NULL) {
resource_uuids = g_hash_table_new_full(qemu_uuid_hash,
uuid_equal_func,
NULL,
g_free);
}
if (g_hash_table_lookup(resource_uuids, uuid) == NULL) {
g_hash_table_insert(resource_uuids, uuid, value);
} else {
result = false;
}
g_mutex_unlock(&lock);
return result;
}
bool virtio_add_dmabuf(QemuUUID *uuid, int udmabuf_fd)
{
bool result;
VirtioSharedObject *vso;
if (udmabuf_fd < 0) {
return false;
}
vso = g_new(VirtioSharedObject, 1);
vso->type = TYPE_DMABUF;
vso->value = GINT_TO_POINTER(udmabuf_fd);
result = virtio_add_resource(uuid, vso);
if (!result) {
g_free(vso);
}
return result;
}
bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev)
{
bool result;
VirtioSharedObject *vso;
if (dev == NULL) {
return false;
}
vso = g_new(VirtioSharedObject, 1);
vso->type = TYPE_VHOST_DEV;
vso->value = dev;
result = virtio_add_resource(uuid, vso);
if (!result) {
g_free(vso);
}
return result;
}
bool virtio_remove_resource(const QemuUUID *uuid)
{
bool result;
g_mutex_lock(&lock);
result = g_hash_table_remove(resource_uuids, uuid);
g_mutex_unlock(&lock);
return result;
}
static VirtioSharedObject *get_shared_object(const QemuUUID *uuid)
{
gpointer lookup_res = NULL;
g_mutex_lock(&lock);
if (resource_uuids != NULL) {
lookup_res = g_hash_table_lookup(resource_uuids, uuid);
}
g_mutex_unlock(&lock);
return (VirtioSharedObject *) lookup_res;
}
int virtio_lookup_dmabuf(const QemuUUID *uuid)
{
VirtioSharedObject *vso = get_shared_object(uuid);
if (vso == NULL) {
return -1;
}
assert(vso->type == TYPE_DMABUF);
return GPOINTER_TO_INT(vso->value);
}
struct vhost_dev *virtio_lookup_vhost_device(const QemuUUID *uuid)
{
VirtioSharedObject *vso = get_shared_object(uuid);
if (vso == NULL) {
return NULL;
}
assert(vso->type == TYPE_VHOST_DEV);
return (struct vhost_dev *) vso->value;
}
SharedObjectType virtio_object_type(const QemuUUID *uuid)
{
VirtioSharedObject *vso = get_shared_object(uuid);
if (vso == NULL) {
return TYPE_INVALID;
}
return vso->type;
}
void virtio_free_resources(void)
{
g_mutex_lock(&lock);
g_hash_table_destroy(resource_uuids);
/* Reference count shall be 0 after the implicit unref on destroy */
resource_uuids = NULL;
g_mutex_unlock(&lock);
}