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| author | Marc Zyngier <marc.zyngier@arm.com> | 2018-11-02 17:16:51 +0000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2018-11-02 19:45:01 -0400 |
| commit | 2cbfdf4df58330f6cb493500387427dae1c5551d (patch) | |
| tree | dd68152e509003dc96217f46443ac25703638f5c /net | |
| parent | 0e9b4a82710220c04100892fb7277b78fd33a747 (diff) | |
| download | lwn-2cbfdf4df58330f6cb493500387427dae1c5551d.tar.gz lwn-2cbfdf4df58330f6cb493500387427dae1c5551d.zip | |
iov_iter: Fix 9p virtio breakage
When switching to the new iovec accessors, a negation got subtly
dropped, leading to 9p being remarkably broken (here with kvmtool):
[ 7.430941] VFS: Mounted root (9p filesystem) on device 0:15.
[ 7.432080] devtmpfs: mounted
[ 7.432717] Freeing unused kernel memory: 1344K
[ 7.433658] Run /virt/init as init process
Warning: unable to translate guest address 0x7e00902ff000 to host
Warning: unable to translate guest address 0x7e00902fefc0 to host
Warning: unable to translate guest address 0x7e00902ff000 to host
Warning: unable to translate guest address 0x7e008febef80 to host
Warning: unable to translate guest address 0x7e008febf000 to host
Warning: unable to translate guest address 0x7e008febef00 to host
Warning: unable to translate guest address 0x7e008febf000 to host
[ 7.436376] Kernel panic - not syncing: Requested init /virt/init failed (error -8).
[ 7.437554] CPU: 29 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8-02267-g00e23707442a #291
[ 7.439006] Hardware name: linux,dummy-virt (DT)
[ 7.439902] Call trace:
[ 7.440387] dump_backtrace+0x0/0x148
[ 7.441104] show_stack+0x14/0x20
[ 7.441768] dump_stack+0x90/0xb4
[ 7.442425] panic+0x120/0x27c
[ 7.443036] kernel_init+0xa4/0x100
[ 7.443725] ret_from_fork+0x10/0x18
[ 7.444444] SMP: stopping secondary CPUs
[ 7.445391] Kernel Offset: disabled
[ 7.446169] CPU features: 0x0,23000438
[ 7.446974] Memory Limit: none
[ 7.447645] ---[ end Kernel panic - not syncing: Requested init /virt/init failed (error -8). ]---
Restoring the missing "!" brings the guest back to life.
Fixes: 00e23707442a ("iov_iter: Use accessor function")
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'net')
| -rw-r--r-- | net/9p/trans_virtio.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 4d7d2070e9c8..ce94e5668ac2 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -322,7 +322,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, if (!iov_iter_count(data)) return 0; - if (iov_iter_is_kvec(data)) { + if (!iov_iter_is_kvec(data)) { int n; /* * We allow only p9_max_pages pinned. We wait for the |