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| author | Stefano Garzarella <sgarzare@redhat.com> | 2023-09-25 12:30:57 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-10-04 08:26:48 +0100 |
| commit | 7aed44babc7f97e82b38e9a68515e699692cc100 (patch) | |
| tree | e527c0c689861df102dd83a329120e48500ac374 /drivers/vhost | |
| parent | a0c55bba0d0d0b5591083f65f830940d8ae63f31 (diff) | |
| download | linux-7aed44babc7f97e82b38e9a68515e699692cc100.tar.gz linux-7aed44babc7f97e82b38e9a68515e699692cc100.tar.bz2 linux-7aed44babc7f97e82b38e9a68515e699692cc100.zip | |
vringh: don't use vringh_kiov_advance() in vringh_iov_xfer()
In the while loop of vringh_iov_xfer(), `partlen` could be 0 if one of
the `iov` has 0 lenght.
In this case, we should skip the iov and go to the next one.
But calling vringh_kiov_advance() with 0 lenght does not cause the
advancement, since it returns immediately if asked to advance by 0 bytes.
Let's restore the code that was there before commit b8c06ad4d67d
("vringh: implement vringh_kiov_advance()"), avoiding using
vringh_kiov_advance().
Fixes: b8c06ad4d67d ("vringh: implement vringh_kiov_advance()")
Cc: stable@vger.kernel.org
Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vringh.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 955d938eb663..7b8fd977f71c 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -123,8 +123,18 @@ static inline ssize_t vringh_iov_xfer(struct vringh *vrh, done += partlen; len -= partlen; ptr += partlen; + iov->consumed += partlen; + iov->iov[iov->i].iov_len -= partlen; + iov->iov[iov->i].iov_base += partlen; - vringh_kiov_advance(iov, partlen); + if (!iov->iov[iov->i].iov_len) { + /* Fix up old iov element then increment. */ + iov->iov[iov->i].iov_len = iov->consumed; + iov->iov[iov->i].iov_base -= iov->consumed; + + iov->consumed = 0; + iov->i++; + } } return done; } |