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| author | Stefano Garzarella <sgarzare@redhat.com> | 2022-11-09 16:42:13 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-12-28 05:28:10 -0500 |
| commit | c070c1912a83432530cbb4271d5b9b11fa36b67a (patch) | |
| tree | f7371e7b877cf574a8475acb1916ac4c9142a17a /drivers/vhost | |
| parent | 98047313cdb46828093894d0ac8b1183b8b317f9 (diff) | |
| download | linux-c070c1912a83432530cbb4271d5b9b11fa36b67a.tar.bz2 | |
vhost-vdpa: fix an iotlb memory leak
Before commit 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB")
we called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during
release to free all the resources allocated when processing user IOTLB
messages through vhost_vdpa_process_iotlb_update().
That commit changed the handling of IOTLB a bit, and we accidentally
removed some code called during the release.
We partially fixed this with commit 037d4305569a ("vhost-vdpa: call
vhost_vdpa_cleanup during the release") but a potential memory leak is
still there as showed by kmemleak if the application does not send
VHOST_IOTLB_INVALIDATE or crashes:
unreferenced object 0xffff888007fbaa30 (size 16):
comm "blkio-bench", pid 914, jiffies 4294993521 (age 885.500s)
hex dump (first 16 bytes):
40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00 @sA.............
backtrace:
[<0000000087736d2a>] kmem_cache_alloc_trace+0x142/0x1c0
[<0000000060740f50>] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa]
[<0000000083e8e205>] vhost_chr_write_iter+0xc0/0x4a0 [vhost]
[<000000008f2f414a>] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa]
[<00000000de1cd4a0>] vfs_write+0x216/0x4b0
[<00000000a2850200>] ksys_write+0x71/0xf0
[<00000000de8e720b>] __x64_sys_write+0x19/0x20
[<0000000018b12cbb>] do_syscall_64+0x3f/0x90
[<00000000986ec465>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Let's fix this calling vhost_vdpa_iotlb_unmap() on the whole range in
vhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup()
since we need a valid v->vdev.mm in vhost_vdpa_pa_unmap().
vhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap()
on the whole range removes all the entries.
The kmemleak log reported was observed with a vDPA device that has `use_va`
set to true (e.g. VDUSE). This patch has been tested with both types of
devices.
Fixes: 037d4305569a ("vhost-vdpa: call vhost_vdpa_cleanup during the release")
Fixes: 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20221109154213.146789-1-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vdpa.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 166044642fd5..b08e07fc7d1f 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -65,6 +65,10 @@ static DEFINE_IDA(vhost_vdpa_ida); static dev_t vhost_vdpa_major; +static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, + struct vhost_iotlb *iotlb, + u64 start, u64 last); + static inline u32 iotlb_to_asid(struct vhost_iotlb *iotlb) { struct vhost_vdpa_as *as = container_of(iotlb, struct @@ -135,7 +139,7 @@ static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid) return -EINVAL; hlist_del(&as->hash_link); - vhost_iotlb_reset(&as->iotlb); + vhost_vdpa_iotlb_unmap(v, &as->iotlb, 0ULL, 0ULL - 1); kfree(as); return 0; @@ -1162,14 +1166,14 @@ static void vhost_vdpa_cleanup(struct vhost_vdpa *v) struct vhost_vdpa_as *as; u32 asid; - vhost_dev_cleanup(&v->vdev); - kfree(v->vdev.vqs); - for (asid = 0; asid < v->vdpa->nas; asid++) { as = asid_to_as(v, asid); if (as) vhost_vdpa_remove_as(v, asid); } + + vhost_dev_cleanup(&v->vdev); + kfree(v->vdev.vqs); } static int vhost_vdpa_open(struct inode *inode, struct file *filep) |