diff options
| author | malc <malc@c046a42c-6fe2-441c-8c8c-71466251a162> | 2009-01-16 22:32:33 +0000 |
|---|---|---|
| committer | malc <malc@c046a42c-6fe2-441c-8c8c-71466251a162> | 2009-01-16 22:32:33 +0000 |
| commit | 63c75dcd669d011f438421980b4379827da4bb1c (patch) | |
| tree | b98f96862b5dd98eb8485ed8cb64c7a681a4fa3f /block-qcow2.c | |
| parent | 4c62180560cc06866aee509b0c0caed310245c1d (diff) | |
| download | qemu-63c75dcd669d011f438421980b4379827da4bb1c.tar.gz | |
Avoid calling qemu_mallocz with zero size
Currently qemu_mallocz calls malloc and handling of zero by malloc is
implementation defined behaviour:
http://www.opengroup.org/onlinepubs/7990989775/xsh/malloc.html
malloc(0) on AIX returns NULL[1] and qcow2 images without snapshots
are thus unusable
[1] Unless special Linux compatibility define is used when compiling
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6359 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'block-qcow2.c')
| -rw-r--r-- | block-qcow2.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/block-qcow2.c b/block-qcow2.c index 9aa7261e3f..d4556efa4e 100644 --- a/block-qcow2.c +++ b/block-qcow2.c @@ -1809,6 +1809,12 @@ static int qcow_read_snapshots(BlockDriverState *bs) int64_t offset; uint32_t extra_data_size; + if (!s->nb_snapshots) { + s->snapshots = NULL; + s->snapshots_size = 0; + return 0; + } + offset = s->snapshots_offset; s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot)); if (!s->snapshots) @@ -2023,8 +2029,10 @@ static int qcow_snapshot_create(BlockDriverState *bs, snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); if (!snapshots1) goto fail; - memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot)); - qemu_free(s->snapshots); + if (s->snapshots) { + memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot)); + qemu_free(s->snapshots); + } s->snapshots = snapshots1; s->snapshots[s->nb_snapshots++] = *sn; |