Re: [Qemu-devel] [PATCH 1/1] hw/9pfs: Fix memory leak in error path

["Andreas Färber" <afaerber@suse.de>]

Am 07.07.2013 19:18, schrieb Aneesh Kumar K.V:
> "M. Mohan Kumar" <mohan@in.ibm.com> writes:
> 
>> From: "M. Mohan Kumar" <mohan@in.ibm.com>
>>
>> Fix few more memory leaks in virtio-9p-device.c detected using valgrind.
>>
>> Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
>> ---
>>  hw/9pfs/virtio-9p-device.c | 26 +++++++++++++++++---------
>>  1 file changed, 17 insertions(+), 9 deletions(-)
>>
>> diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
>> index dc6f4e4..35e2af4 100644
>> --- a/hw/9pfs/virtio-9p-device.c
>> +++ b/hw/9pfs/virtio-9p-device.c
>> @@ -68,14 +68,14 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
>>          fprintf(stderr, "Virtio-9p device couldn't find fsdev with the "
>>                  "id = %s\n",
>>                  s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
>> -        return -1;
>> +        goto out;
>>      }
>>
>>      if (!s->fsconf.tag) {
>>          /* we haven't specified a mount_tag */
>>          fprintf(stderr, "fsdev with id %s needs mount_tag arguments\n",
>>                  s->fsconf.fsdev_id);
>> -        return -1;
>> +        goto out;
>>      }
>>
>>      s->ctx.export_flags = fse->export_flags;
>> @@ -85,10 +85,10 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
>>      if (len > MAX_TAG_LEN - 1) {
>>          fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
>>                  "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
>> -        return -1;
>> +        goto out;
>>      }
>>
>> -    s->tag = strdup(s->fsconf.tag);
>> +    s->tag = g_strdup(s->fsconf.tag);
>>      s->ctx.uid = -1;
>>
>>      s->ops = fse->ops;
>> @@ -99,11 +99,11 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
>>      if (s->ops->init(&s->ctx) < 0) {
>>          fprintf(stderr, "Virtio-9p Failed to initialize fs-driver with id:%s"
>>                  " and export path:%s\n", s->fsconf.fsdev_id, s->ctx.fs_root);
>> -        return -1;
>> +        goto out;
>>      }
>>      if (v9fs_init_worker_threads() < 0) {
>>          fprintf(stderr, "worker thread initialization failed\n");
>> -        return -1;
>> +        goto out;
>>      }
>>
>>      /*
>> @@ -115,18 +115,26 @@ static int virtio_9p_device_init(VirtIODevice *vdev)
>>      if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
>>          fprintf(stderr,
>>                  "error in converting name to path %s", strerror(errno));
>> -        return -1;
>> +        goto out;
>>      }
>>      if (s->ops->lstat(&s->ctx, &path, &stat)) {
>>          fprintf(stderr, "share path %s does not exist\n", fse->path);
>> -        return -1;
>> +        goto out;
>>      } else if (!S_ISDIR(stat.st_mode)) {
>>          fprintf(stderr, "share path %s is not a directory\n", fse->path);
>> -        return -1;
>> +        goto out;
>>      }
>>      v9fs_path_free(&path);
>>
>>      return 0;
>> +out:
>> +    g_free(s->ctx.fs_root);
>> +    g_free(s->tag);
>> +    virtio_cleanup(vdev);
>> +    v9fs_path_free(&path);
>> +
>> +    return -1;
>> +
>>  }
>>
> 
> The error path will result in qemu terminating right ? Do we care about
> g_free in those case ?

See my patches on the list converting VirtioDevices to QOM realize:
Realization grows an Error **errp argument for reporting errors, and
it's up to the caller to decide whether to continue (think device_add)
or terminate (-device).

Andreas

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