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| author | Arnd Bergmann <arnd@arndb.de> | 2017-03-28 18:46:59 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2017-03-28 20:41:28 +0300 |
| commit | f0bb2d50dfcc519f06f901aac88502be6ff1df2c (patch) | |
| tree | 11716cb90806e4de4adb2ae4e89334da92bb5dca /drivers/virtio | |
| parent | 9646b26e85896ef0256e66649f7937f774dc18a6 (diff) | |
| download | lwn-f0bb2d50dfcc519f06f901aac88502be6ff1df2c.tar.gz lwn-f0bb2d50dfcc519f06f901aac88502be6ff1df2c.zip | |
virtio_balloon: prevent uninitialized variable use
The latest gcc-7.0.1 snapshot reports a new warning:
virtio/virtio_balloon.c: In function 'update_balloon_stats':
virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function [-Werror=uninitialized]
virtio/virtio_balloon.c:260:26: error: 'events[3]' is used uninitialized in this function [-Werror=uninitialized]
virtio/virtio_balloon.c:261:56: error: 'events[18]' is used uninitialized in this function [-Werror=uninitialized]
virtio/virtio_balloon.c:262:56: error: 'events[17]' is used uninitialized in this function [-Werror=uninitialized]
This seems absolutely right, so we should add an extra check to
prevent copying uninitialized stack data into the statistics.
>From all I can tell, this has been broken since the statistics code
was originally added in 2.6.34.
Fixes: 9564e138b1f6 ("virtio: Add memory statistics reporting to the balloon driver (V4)")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_balloon.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index d9544db231ef..34adf9b9c053 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -254,12 +254,14 @@ static unsigned int update_balloon_stats(struct virtio_balloon *vb) available = si_mem_available(); +#ifdef CONFIG_VM_EVENT_COUNTERS update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN, pages_to_bytes(events[PSWPIN])); update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_OUT, pages_to_bytes(events[PSWPOUT])); update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]); update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]); +#endif update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE, pages_to_bytes(i.freeram)); update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMTOT, |