linux.git/net/9p, branch v3.10.76

9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers

2014-03-07T05:30:03+00:00

[ Upstream commit b6f52ae2f0d32387bde2b89883e3b64d88b9bfe8 ]

The 9p-virtio transport does zero copy on things larger than 1024 bytes
in size. It accomplishes this by returning the physical addresses of
pages to the virtio-pci device. At present, the translation is usually a
bit shift.

That approach produces an invalid page address when we read/write to
vmalloc buffers, such as those used for Linux kernel modules. Any
attempt to load a Linux kernel module from 9p-virtio produces the
following stack.

[] p9_virtio_zc_request+0x45e/0x510
[] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[] p9_client_read+0x15d/0x240
[] v9fs_fid_readn+0x50/0xa0
[] v9fs_file_readn+0x10/0x20
[] v9fs_file_read+0x37/0x70
[] vfs_read+0x9b/0x160
[] kernel_read+0x41/0x60
[] copy_module_from_fd.isra.34+0xfb/0x180

Subsequently, QEMU will die printing:

qemu-system-x86_64: virtio: trying to map MMIO memory

This patch enables 9p-virtio to correctly handle this case. This not
only enables us to load Linux kernel modules off virtfs, but also
enables ZFS file-based vdevs on virtfs to be used without killing QEMU.

Special thanks to both Avi Kivity and Alexander Graf for their
interpretation of QEMU backtraces. Without their guidence, tracking down
this bug would have taken much longer. Also, special thanks to Linus
Torvalds for his insightful explanation of why this should use
is_vmalloc_addr() instead of is_vmalloc_or_module_addr():

https://lkml.org/lkml/2014/2/8/272

Signed-off-by: Richard Yao 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

9p: send uevent after adding/removing mount_tag attribute

2013-12-04T18:57:19+00:00

commit e0d6cb9cd3a3ac8a3b8e5b22b83c4f8619786f22 upstream.

This driver adds an attribute to the existing virtio device so a CHANGE
event is required in order udev rules to make use of it. The ADD event
happens before this driver is probed and unlike a more typical driver
like a block device there isn't a higher level device to watch for.

Signed-off-by: Michael Marineau 
Signed-off-by: Eric Van Hensbergen 
Signed-off-by: Greg Kroah-Hartman

9p: fix off by one causing access violations and memory corruption

2013-07-28T23:29:58+00:00

[ Upstream commit 110ecd69a9feea82a152bbf9b12aba57e6396883 ]

p9_release_pages() would attempt to dereference one value past the end of
pages[]. This would cause the following crashes:

[ 6293.171817] BUG: unable to handle kernel paging request at ffff8807c96f3000
[ 6293.174146] IP: [] p9_release_pages+0x3b/0x60
[ 6293.176447] PGD 79c5067 PUD 82c1e3067 PMD 82c197067 PTE 80000007c96f3060
[ 6293.180060] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 6293.180060] Modules linked in:
[ 6293.180060] CPU: 62 PID: 174043 Comm: modprobe Tainted: G        W    3.10.0-next-20130710-sasha #3954
[ 6293.180060] task: ffff8807b803b000 ti: ffff880787dde000 task.ti: ffff880787dde000
[ 6293.180060] RIP: 0010:[]  [] p9_release_pages+0x3b/0x60
[ 6293.214316] RSP: 0000:ffff880787ddfc28  EFLAGS: 00010202
[ 6293.214316] RAX: 0000000000000001 RBX: ffff8807c96f2ff8 RCX: 0000000000000000
[ 6293.222017] RDX: ffff8807b803b000 RSI: 0000000000000001 RDI: ffffea001c7e3d40
[ 6293.222017] RBP: ffff880787ddfc48 R08: 0000000000000000 R09: 0000000000000000
[ 6293.222017] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
[ 6293.222017] R13: 0000000000000001 R14: ffff8807cc50c070 R15: ffff8807cc50c070
[ 6293.222017] FS:  00007f572641d700(0000) GS:ffff8807f3600000(0000) knlGS:0000000000000000
[ 6293.256784] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 6293.256784] CR2: ffff8807c96f3000 CR3: 00000007c8e81000 CR4: 00000000000006e0
[ 6293.256784] Stack:
[ 6293.256784]  ffff880787ddfcc8 ffff880787ddfcc8 0000000000000000 ffff880787ddfcc8
[ 6293.256784]  ffff880787ddfd48 ffffffff84128be8 ffff880700000002 0000000000000001
[ 6293.256784]  ffff8807b803b000 ffff880787ddfce0 0000100000000000 0000000000000000
[ 6293.256784] Call Trace:
[ 6293.256784]  [] p9_virtio_zc_request+0x598/0x630
[ 6293.256784]  [] ? wake_up_bit+0x40/0x40
[ 6293.256784]  [] p9_client_zc_rpc+0x111/0x3a0
[ 6293.256784]  [] ? sched_clock_cpu+0x108/0x120
[ 6293.256784]  [] p9_client_read+0xe1/0x2c0
[ 6293.256784]  [] v9fs_file_read+0x90/0xc0
[ 6293.256784]  [] vfs_read+0xc3/0x130
[ 6293.256784]  [] ? trace_hardirqs_on+0xd/0x10
[ 6293.256784]  [] SyS_read+0x62/0xa0
[ 6293.256784]  [] tracesys+0xdd/0xe2
[ 6293.256784] Code: 66 90 48 89 fb 41 89 f5 48 8b 3f 48 85 ff 74 29 85 f6 74 25 45 31 e4 66 0f 1f 84 00 00 00 00 00 e8 eb 14 12 fd 41 ff c4 49 63 c4 <48> 8b 3c c3 48 85 ff 74 05 45 39 e5 75 e7 48 83 c4 08 5b 41 5c
[ 6293.256784] RIP  [] p9_release_pages+0x3b/0x60
[ 6293.256784]  RSP 
[ 6293.256784] CR2: ffff8807c96f3000
[ 6293.256784] ---[ end trace 50822ee72cd360fc ]---

Signed-off-by: Sasha Levin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Merge tag '9p-3.10-bug-fix-1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

2013-06-11T00:35:25+00:00

Pull net/9p bug fix from Eric Van Hensbergen:
 "zero copy error fix"

* tag '9p-3.10-bug-fix-1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  net/9p: Handle error in zero copy request correctly for 9p2000.u

net/9p: Handle error in zero copy request correctly for 9p2000.u

2013-05-28T16:47:57+00:00

For zero copy request, error will be encoded in the user space buffer.
So copy the error code correctly using copy_from_user. Here we use the
extra bytes we allocate for zero copy request. If total error details
are more than P9_ZC_HDR_SZ - 7 bytes, we return -EFAULT. The patch also
avoid a memory allocation in the error path.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Eric Van Hensbergen

Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2013-05-02T21:14:04+00:00

Pull virtio & lguest updates from Rusty Russell:
 "Lots of virtio work which wasn't quite ready for last merge window.

  Plus I dived into lguest again, reworking the pagetable code so we can
  move the switcher page: our fixmaps sometimes take more than 2MB now..."

Ugh.  Annoying conflicts with the tcm_vhost -> vhost_scsi rename.
Hopefully correctly resolved.

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits)
  caif_virtio: Remove bouncing email addresses
  lguest: improve code readability in lg_cpu_start.
  virtio-net: fill only rx queues which are being used
  lguest: map Switcher below fixmap.
  lguest: cache last cpu we ran on.
  lguest: map Switcher text whenever we allocate a new pagetable.
  lguest: don't share Switcher PTE pages between guests.
  lguest: expost switcher_pages array (as lg_switcher_pages).
  lguest: extract shadow PTE walking / allocating.
  lguest: make check_gpte et. al return bool.
  lguest: assume Switcher text is a single page.
  lguest: rename switcher_page to switcher_pages.
  lguest: remove RESERVE_MEM constant.
  lguest: check vaddr not pgd for Switcher protection.
  lguest: prepare to make SWITCHER_ADDR a variable.
  virtio: console: replace EMFILE with EBUSY for already-open port
  virtio-scsi: reset virtqueue affinity when doing cpu hotplug
  virtio-scsi: introduce multiqueue support
  virtio-scsi: push vq lock/unlock into virtscsi_vq_done
  virtio-scsi: pass struct virtio_scsi to virtqueue completion function
  ...

9p/trans_virtio.c: use virtio_add_sgs[]

2013-03-20T05:15:06+00:00

virtio_add_buf() is going away, replaced with virtio_add_sgs() which
takes multiple terminated scatterlists.

Cc: Eric Van Hensbergen 
Signed-off-by: Rusty Russell

Revert parts of "hlist: drop the node parameter from iterators"

2013-03-08T23:05:34+00:00

Commit b67bfe0d42ca ("hlist: drop the node parameter from iterators")
did a lot of nice changes but also contains two small hunks that seem to
have slipped in accidentally and have no apparent connection to the
intent of the patch.

This reverts the two extraneous changes.

Signed-off-by: Arnd Bergmann 
Cc: Peter Senna Tschudin 
Cc: Paul E. McKenney 
Cc: Sasha Levin 
Cc: Thomas Gleixner 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hlist: drop the node parameter from iterators

2013-02-28T03:10:24+00:00

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin 
Acked-by: Paul E. McKenney 
Signed-off-by: Sasha Levin 
Cc: Wu Fengguang 
Cc: Marcelo Tosatti 
Cc: Gleb Natapov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

net/9p: convert to idr_alloc()

2013-02-28T03:10:20+00:00

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo 
Cc: Eric Van Hensbergen 
Cc: Ron Minnich 
Cc: Latchesar Ionkov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds