<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/rxrpc/call_object.c, branch v4.15</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2017-11-29T21:10:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-29T21:10:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96c22a49ac125bc4ceddc0817dfb9ff3de8aea7d'/>
<id>96c22a49ac125bc4ceddc0817dfb9ff3de8aea7d</id>
<content type='text'>
Pull networking fixes from David Miller:

 1) The forcedeth conversion from pci_*() DMA interfaces to dma_*() ones
    missed one spot. From Zhu Yanjun.

 2) Missing CRYPTO_SHA256 Kconfig dep in cfg80211, from Johannes Berg.

 3) Fix checksum offloading in thunderx driver, from Sunil Goutham.

 4) Add SPDX to vm_sockets_diag.h, from Stephen Hemminger.

 5) Fix use after free of packet headers in TIPC, from Jon Maloy.

 6) "sizeof(ptr)" vs "sizeof(*ptr)" bug in i40e, from Gustavo A R Silva.

 7) Tunneling fixes in mlxsw driver, from Petr Machata.

 8) Fix crash in fanout_demux_rollover() of AF_PACKET, from Mike
    Maloney.

 9) Fix race in AF_PACKET bind() vs. NETDEV_UP notifier, from Eric
    Dumazet.

10) Fix regression in sch_sfq.c due to one of the timer_setup()
    conversions. From Paolo Abeni.

11) SCTP does list_for_each_entry() using wrong struct member, fix from
    Xin Long.

12) Don't use big endian netlink attribute read for
    IFLA_BOND_AD_ACTOR_SYSTEM, it is in cpu endianness. Also from Xin
    Long.

13) Fix mis-initialization of q-&gt;link.clock in CBQ scheduler, preventing
    adding filters there. From Jiri Pirko.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits)
  ethernet: dwmac-stm32: Fix copyright
  net: via: via-rhine: use %p to format void * address instead of %x
  net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit
  myri10ge: Update MAINTAINERS
  net: sched: cbq: create block for q-&gt;link.block
  atm: suni: remove extraneous space to fix indentation
  atm: lanai: use %p to format kernel addresses instead of %x
  VSOCK: Don't set sk_state to TCP_CLOSE before testing it
  atm: fore200e: use %pK to format kernel addresses instead of %x
  ambassador: fix incorrect indentation of assignment statement
  vxlan: use __be32 type for the param vni in __vxlan_fdb_delete
  bonding: use nla_get_u64 to extract the value for IFLA_BOND_AD_ACTOR_SYSTEM
  sctp: use right member as the param of list_for_each_entry
  sch_sfq: fix null pointer dereference at timer expiration
  cls_bpf: don't decrement net's refcount when offload fails
  net/packet: fix a race in packet_bind() and packet_notifier()
  packet: fix crash in fanout_demux_rollover()
  sctp: remove extern from stream sched
  sctp: force the params with right types for sctp csum apis
  sctp: force SCTP_ERROR_INV_STRM with __u32 when calling sctp_chunk_fail
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:

 1) The forcedeth conversion from pci_*() DMA interfaces to dma_*() ones
    missed one spot. From Zhu Yanjun.

 2) Missing CRYPTO_SHA256 Kconfig dep in cfg80211, from Johannes Berg.

 3) Fix checksum offloading in thunderx driver, from Sunil Goutham.

 4) Add SPDX to vm_sockets_diag.h, from Stephen Hemminger.

 5) Fix use after free of packet headers in TIPC, from Jon Maloy.

 6) "sizeof(ptr)" vs "sizeof(*ptr)" bug in i40e, from Gustavo A R Silva.

 7) Tunneling fixes in mlxsw driver, from Petr Machata.

 8) Fix crash in fanout_demux_rollover() of AF_PACKET, from Mike
    Maloney.

 9) Fix race in AF_PACKET bind() vs. NETDEV_UP notifier, from Eric
    Dumazet.

10) Fix regression in sch_sfq.c due to one of the timer_setup()
    conversions. From Paolo Abeni.

11) SCTP does list_for_each_entry() using wrong struct member, fix from
    Xin Long.

12) Don't use big endian netlink attribute read for
    IFLA_BOND_AD_ACTOR_SYSTEM, it is in cpu endianness. Also from Xin
    Long.

13) Fix mis-initialization of q-&gt;link.clock in CBQ scheduler, preventing
    adding filters there. From Jiri Pirko.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits)
  ethernet: dwmac-stm32: Fix copyright
  net: via: via-rhine: use %p to format void * address instead of %x
  net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit
  myri10ge: Update MAINTAINERS
  net: sched: cbq: create block for q-&gt;link.block
  atm: suni: remove extraneous space to fix indentation
  atm: lanai: use %p to format kernel addresses instead of %x
  VSOCK: Don't set sk_state to TCP_CLOSE before testing it
  atm: fore200e: use %pK to format kernel addresses instead of %x
  ambassador: fix incorrect indentation of assignment statement
  vxlan: use __be32 type for the param vni in __vxlan_fdb_delete
  bonding: use nla_get_u64 to extract the value for IFLA_BOND_AD_ACTOR_SYSTEM
  sctp: use right member as the param of list_for_each_entry
  sch_sfq: fix null pointer dereference at timer expiration
  cls_bpf: don't decrement net's refcount when offload fails
  net/packet: fix a race in packet_bind() and packet_notifier()
  packet: fix crash in fanout_demux_rollover()
  sctp: remove extern from stream sched
  sctp: force the params with right types for sctp csum apis
  sctp: force SCTP_ERROR_INV_STRM with __u32 when calling sctp_chunk_fail
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Add a timeout for detecting lost ACKs/lost DATA</title>
<updated>2017-11-24T10:18:42+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-11-24T10:18:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bd1fdf8cfdf3fdbccd2b21c33ec649ebd7429af7'/>
<id>bd1fdf8cfdf3fdbccd2b21c33ec649ebd7429af7</id>
<content type='text'>
Add an extra timeout that is set/updated when we send a DATA packet that
has the request-ack flag set.  This allows us to detect if we don't get an
ACK in response to the latest flagged packet.

The ACK packet is adjudged to have been lost if it doesn't turn up within
2*RTT of the transmission.

If the timeout occurs, we schedule the sending of a PING ACK to find out
the state of the other side.  If a new DATA packet is ready to go sooner,
we cancel the sending of the ping and set the request-ack flag on that
instead.

If we get back a PING-RESPONSE ACK that indicates a lower tx_top than what
we had at the time of the ping transmission, we adjudge all the DATA
packets sent between the response tx_top and the ping-time tx_top to have
been lost and retransmit immediately.

Rather than sending a PING ACK, we could just pick a DATA packet and
speculatively retransmit that with request-ack set.  It should result in
either a REQUESTED ACK or a DUPLICATE ACK which we can then use in lieu the
a PING-RESPONSE ACK mentioned above.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add an extra timeout that is set/updated when we send a DATA packet that
has the request-ack flag set.  This allows us to detect if we don't get an
ACK in response to the latest flagged packet.

The ACK packet is adjudged to have been lost if it doesn't turn up within
2*RTT of the transmission.

If the timeout occurs, we schedule the sending of a PING ACK to find out
the state of the other side.  If a new DATA packet is ready to go sooner,
we cancel the sending of the ping and set the request-ack flag on that
instead.

If we get back a PING-RESPONSE ACK that indicates a lower tx_top than what
we had at the time of the ping transmission, we adjudge all the DATA
packets sent between the response tx_top and the ping-time tx_top to have
been lost and retransmit immediately.

Rather than sending a PING ACK, we could just pick a DATA packet and
speculatively retransmit that with request-ack set.  It should result in
either a REQUESTED ACK or a DUPLICATE ACK which we can then use in lieu the
a PING-RESPONSE ACK mentioned above.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Fix call timeouts</title>
<updated>2017-11-24T10:18:41+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-11-24T10:18:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a158bdd3247b9656df36ba133235fff702e9fdc3'/>
<id>a158bdd3247b9656df36ba133235fff702e9fdc3</id>
<content type='text'>
Fix the rxrpc call expiration timeouts and make them settable from
userspace.  By analogy with other rx implementations, there should be three
timeouts:

 (1) "Normal timeout"

     This is set for all calls and is triggered if we haven't received any
     packets from the peer in a while.  It is measured from the last time
     we received any packet on that call.  This is not reset by any
     connection packets (such as CHALLENGE/RESPONSE packets).

     If a service operation takes a long time, the server should generate
     PING ACKs at a duration that's substantially less than the normal
     timeout so is to keep both sides alive.  This is set at 1/6 of normal
     timeout.

 (2) "Idle timeout"

     This is set only for a service call and is triggered if we stop
     receiving the DATA packets that comprise the request data.  It is
     measured from the last time we received a DATA packet.

 (3) "Hard timeout"

     This can be set for a call and specified the maximum lifetime of that
     call.  It should not be specified by default.  Some operations (such
     as volume transfer) take a long time.

Allow userspace to set/change the timeouts on a call with sendmsg, using a
control message:

	RXRPC_SET_CALL_TIMEOUTS

The data to the message is a number of 32-bit words, not all of which need
be given:

	u32 hard_timeout;	/* sec from first packet */
	u32 idle_timeout;	/* msec from packet Rx */
	u32 normal_timeout;	/* msec from data Rx */

This can be set in combination with any other sendmsg() that affects a
call.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix the rxrpc call expiration timeouts and make them settable from
userspace.  By analogy with other rx implementations, there should be three
timeouts:

 (1) "Normal timeout"

     This is set for all calls and is triggered if we haven't received any
     packets from the peer in a while.  It is measured from the last time
     we received any packet on that call.  This is not reset by any
     connection packets (such as CHALLENGE/RESPONSE packets).

     If a service operation takes a long time, the server should generate
     PING ACKs at a duration that's substantially less than the normal
     timeout so is to keep both sides alive.  This is set at 1/6 of normal
     timeout.

 (2) "Idle timeout"

     This is set only for a service call and is triggered if we stop
     receiving the DATA packets that comprise the request data.  It is
     measured from the last time we received a DATA packet.

 (3) "Hard timeout"

     This can be set for a call and specified the maximum lifetime of that
     call.  It should not be specified by default.  Some operations (such
     as volume transfer) take a long time.

Allow userspace to set/change the timeouts on a call with sendmsg, using a
control message:

	RXRPC_SET_CALL_TIMEOUTS

The data to the message is a number of 32-bit words, not all of which need
be given:

	u32 hard_timeout;	/* sec from first packet */
	u32 idle_timeout;	/* msec from packet Rx */
	u32 normal_timeout;	/* msec from data Rx */

This can be set in combination with any other sendmsg() that affects a
call.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Split the call params from the operation params</title>
<updated>2017-11-24T10:18:41+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-11-24T10:18:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4812417894770f8c13e5dd8a66479ae44f4b01ff'/>
<id>4812417894770f8c13e5dd8a66479ae44f4b01ff</id>
<content type='text'>
When rxrpc_sendmsg() parses the control message buffer, it places the
parameters extracted into a structure, but lumps together call parameters
(such as user call ID) with operation parameters (such as whether to send
data, send an abort or accept a call).

Split the call parameters out into their own structure, a copy of which is
then embedded in the operation parameters struct.

The call parameters struct is then passed down into the places that need it
instead of passing the individual parameters.  This allows for extra call
parameters to be added.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When rxrpc_sendmsg() parses the control message buffer, it places the
parameters extracted into a structure, but lumps together call parameters
(such as user call ID) with operation parameters (such as whether to send
data, send an abort or accept a call).

Split the call parameters out into their own structure, a copy of which is
then embedded in the operation parameters struct.

The call parameters struct is then passed down into the places that need it
instead of passing the individual parameters.  This allows for extra call
parameters to be added.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Provide a different lockdep key for call-&gt;user_mutex for kernel calls</title>
<updated>2017-11-24T10:18:40+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-11-24T10:18:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9faaff593404a9c4e5abc6839a641635d7b9d0cd'/>
<id>9faaff593404a9c4e5abc6839a641635d7b9d0cd</id>
<content type='text'>
Provide a different lockdep key for rxrpc_call::user_mutex when the call is
made on a kernel socket, such as by the AFS filesystem.

The problem is that lockdep registers a false positive between userspace
calling the sendmsg syscall on a user socket where call-&gt;user_mutex is held
whilst userspace memory is accessed whereas the AFS filesystem may perform
operations with mmap_sem held by the caller.

In such a case, the following warning is produced.

======================================================
WARNING: possible circular locking dependency detected
4.14.0-fscache+ #243 Tainted: G            E
------------------------------------------------------
modpost/16701 is trying to acquire lock:
 (&amp;vnode-&gt;io_lock){+.+.}, at: [&lt;ffffffffa000fc40&gt;] afs_begin_vnode_operation+0x33/0x77 [kafs]

but task is already holding lock:
 (&amp;mm-&gt;mmap_sem){++++}, at: [&lt;ffffffff8104376a&gt;] __do_page_fault+0x1ef/0x486

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #3 (&amp;mm-&gt;mmap_sem){++++}:
       __might_fault+0x61/0x89
       _copy_from_iter_full+0x40/0x1fa
       rxrpc_send_data+0x8dc/0xff3
       rxrpc_do_sendmsg+0x62f/0x6a1
       rxrpc_sendmsg+0x166/0x1b7
       sock_sendmsg+0x2d/0x39
       ___sys_sendmsg+0x1ad/0x22b
       __sys_sendmsg+0x41/0x62
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-&gt; #2 (&amp;call-&gt;user_mutex){+.+.}:
       __mutex_lock+0x86/0x7d2
       rxrpc_new_client_call+0x378/0x80e
       rxrpc_kernel_begin_call+0xf3/0x154
       afs_make_call+0x195/0x454 [kafs]
       afs_vl_get_capabilities+0x193/0x198 [kafs]
       afs_vl_lookup_vldb+0x5f/0x151 [kafs]
       afs_create_volume+0x2e/0x2f4 [kafs]
       afs_mount+0x56a/0x8d7 [kafs]
       mount_fs+0x6a/0x109
       vfs_kern_mount+0x67/0x135
       do_mount+0x90b/0xb57
       SyS_mount+0x72/0x98
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-&gt; #1 (k-sk_lock-AF_RXRPC){+.+.}:
       lock_sock_nested+0x74/0x8a
       rxrpc_kernel_begin_call+0x8a/0x154
       afs_make_call+0x195/0x454 [kafs]
       afs_fs_get_capabilities+0x17a/0x17f [kafs]
       afs_probe_fileserver+0xf7/0x2f0 [kafs]
       afs_select_fileserver+0x83f/0x903 [kafs]
       afs_fetch_status+0x89/0x11d [kafs]
       afs_iget+0x16f/0x4f8 [kafs]
       afs_mount+0x6c6/0x8d7 [kafs]
       mount_fs+0x6a/0x109
       vfs_kern_mount+0x67/0x135
       do_mount+0x90b/0xb57
       SyS_mount+0x72/0x98
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-&gt; #0 (&amp;vnode-&gt;io_lock){+.+.}:
       lock_acquire+0x174/0x19f
       __mutex_lock+0x86/0x7d2
       afs_begin_vnode_operation+0x33/0x77 [kafs]
       afs_fetch_data+0x80/0x12a [kafs]
       afs_readpages+0x314/0x405 [kafs]
       __do_page_cache_readahead+0x203/0x2ba
       filemap_fault+0x179/0x54d
       __do_fault+0x17/0x60
       __handle_mm_fault+0x6d7/0x95c
       handle_mm_fault+0x24e/0x2a3
       __do_page_fault+0x301/0x486
       do_page_fault+0x236/0x259
       page_fault+0x22/0x30
       __clear_user+0x3d/0x60
       padzero+0x1c/0x2b
       load_elf_binary+0x785/0xdc7
       search_binary_handler+0x81/0x1ff
       do_execveat_common.isra.14+0x600/0x888
       do_execve+0x1f/0x21
       SyS_execve+0x28/0x2f
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

other info that might help us debug this:

Chain exists of:
  &amp;vnode-&gt;io_lock --&gt; &amp;call-&gt;user_mutex --&gt; &amp;mm-&gt;mmap_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&amp;mm-&gt;mmap_sem);
                               lock(&amp;call-&gt;user_mutex);
                               lock(&amp;mm-&gt;mmap_sem);
  lock(&amp;vnode-&gt;io_lock);

 *** DEADLOCK ***

1 lock held by modpost/16701:
 #0:  (&amp;mm-&gt;mmap_sem){++++}, at: [&lt;ffffffff8104376a&gt;] __do_page_fault+0x1ef/0x486

stack backtrace:
CPU: 0 PID: 16701 Comm: modpost Tainted: G            E   4.14.0-fscache+ #243
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
 dump_stack+0x67/0x8e
 print_circular_bug+0x341/0x34f
 check_prev_add+0x11f/0x5d4
 ? add_lock_to_list.isra.12+0x8b/0x8b
 ? add_lock_to_list.isra.12+0x8b/0x8b
 ? __lock_acquire+0xf77/0x10b4
 __lock_acquire+0xf77/0x10b4
 lock_acquire+0x174/0x19f
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 __mutex_lock+0x86/0x7d2
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 afs_begin_vnode_operation+0x33/0x77 [kafs]
 afs_fetch_data+0x80/0x12a [kafs]
 afs_readpages+0x314/0x405 [kafs]
 __do_page_cache_readahead+0x203/0x2ba
 ? filemap_fault+0x179/0x54d
 filemap_fault+0x179/0x54d
 __do_fault+0x17/0x60
 __handle_mm_fault+0x6d7/0x95c
 handle_mm_fault+0x24e/0x2a3
 __do_page_fault+0x301/0x486
 do_page_fault+0x236/0x259
 page_fault+0x22/0x30
RIP: 0010:__clear_user+0x3d/0x60
RSP: 0018:ffff880071e93da0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000011c RCX: 000000000000011c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000060f720
RBP: 000000000060f720 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8800b5459b68 R12: ffff8800ce150e00
R13: 000000000060f720 R14: 00000000006127a8 R15: 0000000000000000
 padzero+0x1c/0x2b
 load_elf_binary+0x785/0xdc7
 search_binary_handler+0x81/0x1ff
 do_execveat_common.isra.14+0x600/0x888
 do_execve+0x1f/0x21
 SyS_execve+0x28/0x2f
 do_syscall_64+0x89/0x1be
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7fdb6009ee07
RSP: 002b:00007fff566d9728 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055ba57280900 RCX: 00007fdb6009ee07
RDX: 000055ba5727f270 RSI: 000055ba5727cac0 RDI: 000055ba57280900
RBP: 000055ba57280900 R08: 00007fff566d9700 R09: 0000000000000000
R10: 000055ba5727cac0 R11: 0000000000000246 R12: 0000000000000000
R13: 000055ba5727cac0 R14: 000055ba5727f270 R15: 0000000000000000

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Provide a different lockdep key for rxrpc_call::user_mutex when the call is
made on a kernel socket, such as by the AFS filesystem.

The problem is that lockdep registers a false positive between userspace
calling the sendmsg syscall on a user socket where call-&gt;user_mutex is held
whilst userspace memory is accessed whereas the AFS filesystem may perform
operations with mmap_sem held by the caller.

In such a case, the following warning is produced.

======================================================
WARNING: possible circular locking dependency detected
4.14.0-fscache+ #243 Tainted: G            E
------------------------------------------------------
modpost/16701 is trying to acquire lock:
 (&amp;vnode-&gt;io_lock){+.+.}, at: [&lt;ffffffffa000fc40&gt;] afs_begin_vnode_operation+0x33/0x77 [kafs]

but task is already holding lock:
 (&amp;mm-&gt;mmap_sem){++++}, at: [&lt;ffffffff8104376a&gt;] __do_page_fault+0x1ef/0x486

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #3 (&amp;mm-&gt;mmap_sem){++++}:
       __might_fault+0x61/0x89
       _copy_from_iter_full+0x40/0x1fa
       rxrpc_send_data+0x8dc/0xff3
       rxrpc_do_sendmsg+0x62f/0x6a1
       rxrpc_sendmsg+0x166/0x1b7
       sock_sendmsg+0x2d/0x39
       ___sys_sendmsg+0x1ad/0x22b
       __sys_sendmsg+0x41/0x62
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-&gt; #2 (&amp;call-&gt;user_mutex){+.+.}:
       __mutex_lock+0x86/0x7d2
       rxrpc_new_client_call+0x378/0x80e
       rxrpc_kernel_begin_call+0xf3/0x154
       afs_make_call+0x195/0x454 [kafs]
       afs_vl_get_capabilities+0x193/0x198 [kafs]
       afs_vl_lookup_vldb+0x5f/0x151 [kafs]
       afs_create_volume+0x2e/0x2f4 [kafs]
       afs_mount+0x56a/0x8d7 [kafs]
       mount_fs+0x6a/0x109
       vfs_kern_mount+0x67/0x135
       do_mount+0x90b/0xb57
       SyS_mount+0x72/0x98
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-&gt; #1 (k-sk_lock-AF_RXRPC){+.+.}:
       lock_sock_nested+0x74/0x8a
       rxrpc_kernel_begin_call+0x8a/0x154
       afs_make_call+0x195/0x454 [kafs]
       afs_fs_get_capabilities+0x17a/0x17f [kafs]
       afs_probe_fileserver+0xf7/0x2f0 [kafs]
       afs_select_fileserver+0x83f/0x903 [kafs]
       afs_fetch_status+0x89/0x11d [kafs]
       afs_iget+0x16f/0x4f8 [kafs]
       afs_mount+0x6c6/0x8d7 [kafs]
       mount_fs+0x6a/0x109
       vfs_kern_mount+0x67/0x135
       do_mount+0x90b/0xb57
       SyS_mount+0x72/0x98
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-&gt; #0 (&amp;vnode-&gt;io_lock){+.+.}:
       lock_acquire+0x174/0x19f
       __mutex_lock+0x86/0x7d2
       afs_begin_vnode_operation+0x33/0x77 [kafs]
       afs_fetch_data+0x80/0x12a [kafs]
       afs_readpages+0x314/0x405 [kafs]
       __do_page_cache_readahead+0x203/0x2ba
       filemap_fault+0x179/0x54d
       __do_fault+0x17/0x60
       __handle_mm_fault+0x6d7/0x95c
       handle_mm_fault+0x24e/0x2a3
       __do_page_fault+0x301/0x486
       do_page_fault+0x236/0x259
       page_fault+0x22/0x30
       __clear_user+0x3d/0x60
       padzero+0x1c/0x2b
       load_elf_binary+0x785/0xdc7
       search_binary_handler+0x81/0x1ff
       do_execveat_common.isra.14+0x600/0x888
       do_execve+0x1f/0x21
       SyS_execve+0x28/0x2f
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

other info that might help us debug this:

Chain exists of:
  &amp;vnode-&gt;io_lock --&gt; &amp;call-&gt;user_mutex --&gt; &amp;mm-&gt;mmap_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&amp;mm-&gt;mmap_sem);
                               lock(&amp;call-&gt;user_mutex);
                               lock(&amp;mm-&gt;mmap_sem);
  lock(&amp;vnode-&gt;io_lock);

 *** DEADLOCK ***

1 lock held by modpost/16701:
 #0:  (&amp;mm-&gt;mmap_sem){++++}, at: [&lt;ffffffff8104376a&gt;] __do_page_fault+0x1ef/0x486

stack backtrace:
CPU: 0 PID: 16701 Comm: modpost Tainted: G            E   4.14.0-fscache+ #243
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
 dump_stack+0x67/0x8e
 print_circular_bug+0x341/0x34f
 check_prev_add+0x11f/0x5d4
 ? add_lock_to_list.isra.12+0x8b/0x8b
 ? add_lock_to_list.isra.12+0x8b/0x8b
 ? __lock_acquire+0xf77/0x10b4
 __lock_acquire+0xf77/0x10b4
 lock_acquire+0x174/0x19f
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 __mutex_lock+0x86/0x7d2
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 afs_begin_vnode_operation+0x33/0x77 [kafs]
 afs_fetch_data+0x80/0x12a [kafs]
 afs_readpages+0x314/0x405 [kafs]
 __do_page_cache_readahead+0x203/0x2ba
 ? filemap_fault+0x179/0x54d
 filemap_fault+0x179/0x54d
 __do_fault+0x17/0x60
 __handle_mm_fault+0x6d7/0x95c
 handle_mm_fault+0x24e/0x2a3
 __do_page_fault+0x301/0x486
 do_page_fault+0x236/0x259
 page_fault+0x22/0x30
RIP: 0010:__clear_user+0x3d/0x60
RSP: 0018:ffff880071e93da0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000011c RCX: 000000000000011c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000060f720
RBP: 000000000060f720 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8800b5459b68 R12: ffff8800ce150e00
R13: 000000000060f720 R14: 00000000006127a8 R15: 0000000000000000
 padzero+0x1c/0x2b
 load_elf_binary+0x785/0xdc7
 search_binary_handler+0x81/0x1ff
 do_execveat_common.isra.14+0x600/0x888
 do_execve+0x1f/0x21
 SyS_execve+0x28/0x2f
 do_syscall_64+0x89/0x1be
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7fdb6009ee07
RSP: 002b:00007fff566d9728 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055ba57280900 RCX: 00007fdb6009ee07
RDX: 000055ba5727f270 RSI: 000055ba5727cac0 RDI: 000055ba57280900
RBP: 000055ba57280900 R08: 00007fff566d9700 R09: 0000000000000000
R10: 000055ba5727cac0 R11: 0000000000000246 R12: 0000000000000000
R13: 000055ba5727cac0 R14: 000055ba5727f270 R15: 0000000000000000

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: setup_timer() -&gt; timer_setup()</title>
<updated>2017-11-21T23:57:07+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2017-10-16T21:43:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e99e88a9d2b067465adaa9c111ada99a041bef9a'/>
<id>e99e88a9d2b067465adaa9c111ada99a041bef9a</id>
<content type='text'>
This converts all remaining cases of the old setup_timer() API into using
timer_setup(), where the callback argument is the structure already
holding the struct timer_list. These should have no behavioral changes,
since they just change which pointer is passed into the callback with
the same available pointers after conversion. It handles the following
examples, in addition to some other variations.

Casting from unsigned long:

    void my_callback(unsigned long data)
    {
        struct something *ptr = (struct something *)data;
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, ptr);

and forced object casts:

    void my_callback(struct something *ptr)
    {
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, (unsigned long)ptr);

become:

    void my_callback(struct timer_list *t)
    {
        struct something *ptr = from_timer(ptr, t, my_timer);
    ...
    }
    ...
    timer_setup(&amp;ptr-&gt;my_timer, my_callback, 0);

Direct function assignments:

    void my_callback(unsigned long data)
    {
        struct something *ptr = (struct something *)data;
    ...
    }
    ...
    ptr-&gt;my_timer.function = my_callback;

have a temporary cast added, along with converting the args:

    void my_callback(struct timer_list *t)
    {
        struct something *ptr = from_timer(ptr, t, my_timer);
    ...
    }
    ...
    ptr-&gt;my_timer.function = (TIMER_FUNC_TYPE)my_callback;

And finally, callbacks without a data assignment:

    void my_callback(unsigned long data)
    {
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, 0);

have their argument renamed to verify they're unused during conversion:

    void my_callback(struct timer_list *unused)
    {
    ...
    }
    ...
    timer_setup(&amp;ptr-&gt;my_timer, my_callback, 0);

The conversion is done with the following Coccinelle script:

spatch --very-quiet --all-includes --include-headers \
	-I ./arch/x86/include -I ./arch/x86/include/generated \
	-I ./include -I ./arch/x86/include/uapi \
	-I ./arch/x86/include/generated/uapi -I ./include/uapi \
	-I ./include/generated/uapi --include ./include/linux/kconfig.h \
	--dir . \
	--cocci-file ~/src/data/timer_setup.cocci

@fix_address_of@
expression e;
@@

 setup_timer(
-&amp;(e)
+&amp;e
 , ...)

// Update any raw setup_timer() usages that have a NULL callback, but
// would otherwise match change_timer_function_usage, since the latter
// will update all function assignments done in the face of a NULL
// function initialization in setup_timer().
@change_timer_function_usage_NULL@
expression _E;
identifier _timer;
type _cast_data;
@@

(
-setup_timer(&amp;_E-&gt;_timer, NULL, _E);
+timer_setup(&amp;_E-&gt;_timer, NULL, 0);
|
-setup_timer(&amp;_E-&gt;_timer, NULL, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, NULL, 0);
|
-setup_timer(&amp;_E._timer, NULL, &amp;_E);
+timer_setup(&amp;_E._timer, NULL, 0);
|
-setup_timer(&amp;_E._timer, NULL, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, NULL, 0);
)

@change_timer_function_usage@
expression _E;
identifier _timer;
struct timer_list _stl;
identifier _callback;
type _cast_func, _cast_data;
@@

(
-setup_timer(&amp;_E-&gt;_timer, _callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, &amp;_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, &amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)&amp;_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)&amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, &amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, &amp;_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)&amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)&amp;_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
 _E-&gt;_timer@_stl.function = _callback;
|
 _E-&gt;_timer@_stl.function = &amp;_callback;
|
 _E-&gt;_timer@_stl.function = (_cast_func)_callback;
|
 _E-&gt;_timer@_stl.function = (_cast_func)&amp;_callback;
|
 _E._timer@_stl.function = _callback;
|
 _E._timer@_stl.function = &amp;_callback;
|
 _E._timer@_stl.function = (_cast_func)_callback;
|
 _E._timer@_stl.function = (_cast_func)&amp;_callback;
)

// callback(unsigned long arg)
@change_callback_handle_cast
 depends on change_timer_function_usage@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _origtype;
identifier _origarg;
type _handletype;
identifier _handle;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *t
 )
 {
(
	... when != _origarg
	_handletype *_handle =
-(_handletype *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle =
-(void *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle;
	... when != _handle
	_handle =
-(_handletype *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle;
	... when != _handle
	_handle =
-(void *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
)
 }

// callback(unsigned long arg) without existing variable
@change_callback_handle_cast_no_arg
 depends on change_timer_function_usage &amp;&amp;
                     !change_callback_handle_cast@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _origtype;
identifier _origarg;
type _handletype;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *t
 )
 {
+	_handletype *_origarg = from_timer(_origarg, t, _timer);
+
	... when != _origarg
-	(_handletype *)_origarg
+	_origarg
	... when != _origarg
 }

// Avoid already converted callbacks.
@match_callback_converted
 depends on change_timer_function_usage &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
	    !change_callback_handle_cast_no_arg@
identifier change_timer_function_usage._callback;
identifier t;
@@

 void _callback(struct timer_list *t)
 { ... }

// callback(struct something *handle)
@change_callback_handle_arg
 depends on change_timer_function_usage &amp;&amp;
	    !match_callback_converted &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
            !change_callback_handle_cast_no_arg@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _handletype;
identifier _handle;
@@

 void _callback(
-_handletype *_handle
+struct timer_list *t
 )
 {
+	_handletype *_handle = from_timer(_handle, t, _timer);
	...
 }

// If change_callback_handle_arg ran on an empty function, remove
// the added handler.
@unchange_callback_handle_arg
 depends on change_timer_function_usage &amp;&amp;
	    change_callback_handle_arg@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _handletype;
identifier _handle;
identifier t;
@@

 void _callback(struct timer_list *t)
 {
-	_handletype *_handle = from_timer(_handle, t, _timer);
 }

// We only want to refactor the setup_timer() data argument if we've found
// the matching callback. This undoes changes in change_timer_function_usage.
@unchange_timer_function_usage
 depends on change_timer_function_usage &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
            !change_callback_handle_cast_no_arg &amp;&amp;
	    !change_callback_handle_arg@
expression change_timer_function_usage._E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type change_timer_function_usage._cast_data;
@@

(
-timer_setup(&amp;_E-&gt;_timer, _callback, 0);
+setup_timer(&amp;_E-&gt;_timer, _callback, (_cast_data)_E);
|
-timer_setup(&amp;_E._timer, _callback, 0);
+setup_timer(&amp;_E._timer, _callback, (_cast_data)&amp;_E);
)

// If we fixed a callback from a .function assignment, fix the
// assignment cast now.
@change_timer_function_assignment
 depends on change_timer_function_usage &amp;&amp;
            (change_callback_handle_cast ||
             change_callback_handle_cast_no_arg ||
             change_callback_handle_arg)@
expression change_timer_function_usage._E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type _cast_func;
typedef TIMER_FUNC_TYPE;
@@

(
 _E-&gt;_timer.function =
-_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-(_cast_func)_callback;
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-(_cast_func)&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-&amp;_callback;
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-(_cast_func)_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-(_cast_func)&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
)

// Sometimes timer functions are called directly. Replace matched args.
@change_timer_function_calls
 depends on change_timer_function_usage &amp;&amp;
            (change_callback_handle_cast ||
             change_callback_handle_cast_no_arg ||
             change_callback_handle_arg)@
expression _E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type _cast_data;
@@

 _callback(
(
-(_cast_data)_E
+&amp;_E-&gt;_timer
|
-(_cast_data)&amp;_E
+&amp;_E._timer
|
-_E
+&amp;_E-&gt;_timer
)
 )

// If a timer has been configured without a data argument, it can be
// converted without regard to the callback argument, since it is unused.
@match_timer_function_unused_data@
expression _E;
identifier _timer;
identifier _callback;
@@

(
-setup_timer(&amp;_E-&gt;_timer, _callback, 0);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, 0L);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, 0UL);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0L);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0UL);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0L);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0UL);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0);
+timer_setup(_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0L);
+timer_setup(_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0UL);
+timer_setup(_timer, _callback, 0);
)

@change_callback_unused_data
 depends on match_timer_function_unused_data@
identifier match_timer_function_unused_data._callback;
type _origtype;
identifier _origarg;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *unused
 )
 {
	... when != _origarg
 }

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This converts all remaining cases of the old setup_timer() API into using
timer_setup(), where the callback argument is the structure already
holding the struct timer_list. These should have no behavioral changes,
since they just change which pointer is passed into the callback with
the same available pointers after conversion. It handles the following
examples, in addition to some other variations.

Casting from unsigned long:

    void my_callback(unsigned long data)
    {
        struct something *ptr = (struct something *)data;
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, ptr);

and forced object casts:

    void my_callback(struct something *ptr)
    {
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, (unsigned long)ptr);

become:

    void my_callback(struct timer_list *t)
    {
        struct something *ptr = from_timer(ptr, t, my_timer);
    ...
    }
    ...
    timer_setup(&amp;ptr-&gt;my_timer, my_callback, 0);

Direct function assignments:

    void my_callback(unsigned long data)
    {
        struct something *ptr = (struct something *)data;
    ...
    }
    ...
    ptr-&gt;my_timer.function = my_callback;

have a temporary cast added, along with converting the args:

    void my_callback(struct timer_list *t)
    {
        struct something *ptr = from_timer(ptr, t, my_timer);
    ...
    }
    ...
    ptr-&gt;my_timer.function = (TIMER_FUNC_TYPE)my_callback;

And finally, callbacks without a data assignment:

    void my_callback(unsigned long data)
    {
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, 0);

have their argument renamed to verify they're unused during conversion:

    void my_callback(struct timer_list *unused)
    {
    ...
    }
    ...
    timer_setup(&amp;ptr-&gt;my_timer, my_callback, 0);

The conversion is done with the following Coccinelle script:

spatch --very-quiet --all-includes --include-headers \
	-I ./arch/x86/include -I ./arch/x86/include/generated \
	-I ./include -I ./arch/x86/include/uapi \
	-I ./arch/x86/include/generated/uapi -I ./include/uapi \
	-I ./include/generated/uapi --include ./include/linux/kconfig.h \
	--dir . \
	--cocci-file ~/src/data/timer_setup.cocci

@fix_address_of@
expression e;
@@

 setup_timer(
-&amp;(e)
+&amp;e
 , ...)

// Update any raw setup_timer() usages that have a NULL callback, but
// would otherwise match change_timer_function_usage, since the latter
// will update all function assignments done in the face of a NULL
// function initialization in setup_timer().
@change_timer_function_usage_NULL@
expression _E;
identifier _timer;
type _cast_data;
@@

(
-setup_timer(&amp;_E-&gt;_timer, NULL, _E);
+timer_setup(&amp;_E-&gt;_timer, NULL, 0);
|
-setup_timer(&amp;_E-&gt;_timer, NULL, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, NULL, 0);
|
-setup_timer(&amp;_E._timer, NULL, &amp;_E);
+timer_setup(&amp;_E._timer, NULL, 0);
|
-setup_timer(&amp;_E._timer, NULL, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, NULL, 0);
)

@change_timer_function_usage@
expression _E;
identifier _timer;
struct timer_list _stl;
identifier _callback;
type _cast_func, _cast_data;
@@

(
-setup_timer(&amp;_E-&gt;_timer, _callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, &amp;_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, &amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)&amp;_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)&amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, &amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, &amp;_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)&amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)&amp;_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
 _E-&gt;_timer@_stl.function = _callback;
|
 _E-&gt;_timer@_stl.function = &amp;_callback;
|
 _E-&gt;_timer@_stl.function = (_cast_func)_callback;
|
 _E-&gt;_timer@_stl.function = (_cast_func)&amp;_callback;
|
 _E._timer@_stl.function = _callback;
|
 _E._timer@_stl.function = &amp;_callback;
|
 _E._timer@_stl.function = (_cast_func)_callback;
|
 _E._timer@_stl.function = (_cast_func)&amp;_callback;
)

// callback(unsigned long arg)
@change_callback_handle_cast
 depends on change_timer_function_usage@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _origtype;
identifier _origarg;
type _handletype;
identifier _handle;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *t
 )
 {
(
	... when != _origarg
	_handletype *_handle =
-(_handletype *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle =
-(void *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle;
	... when != _handle
	_handle =
-(_handletype *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle;
	... when != _handle
	_handle =
-(void *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
)
 }

// callback(unsigned long arg) without existing variable
@change_callback_handle_cast_no_arg
 depends on change_timer_function_usage &amp;&amp;
                     !change_callback_handle_cast@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _origtype;
identifier _origarg;
type _handletype;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *t
 )
 {
+	_handletype *_origarg = from_timer(_origarg, t, _timer);
+
	... when != _origarg
-	(_handletype *)_origarg
+	_origarg
	... when != _origarg
 }

// Avoid already converted callbacks.
@match_callback_converted
 depends on change_timer_function_usage &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
	    !change_callback_handle_cast_no_arg@
identifier change_timer_function_usage._callback;
identifier t;
@@

 void _callback(struct timer_list *t)
 { ... }

// callback(struct something *handle)
@change_callback_handle_arg
 depends on change_timer_function_usage &amp;&amp;
	    !match_callback_converted &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
            !change_callback_handle_cast_no_arg@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _handletype;
identifier _handle;
@@

 void _callback(
-_handletype *_handle
+struct timer_list *t
 )
 {
+	_handletype *_handle = from_timer(_handle, t, _timer);
	...
 }

// If change_callback_handle_arg ran on an empty function, remove
// the added handler.
@unchange_callback_handle_arg
 depends on change_timer_function_usage &amp;&amp;
	    change_callback_handle_arg@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _handletype;
identifier _handle;
identifier t;
@@

 void _callback(struct timer_list *t)
 {
-	_handletype *_handle = from_timer(_handle, t, _timer);
 }

// We only want to refactor the setup_timer() data argument if we've found
// the matching callback. This undoes changes in change_timer_function_usage.
@unchange_timer_function_usage
 depends on change_timer_function_usage &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
            !change_callback_handle_cast_no_arg &amp;&amp;
	    !change_callback_handle_arg@
expression change_timer_function_usage._E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type change_timer_function_usage._cast_data;
@@

(
-timer_setup(&amp;_E-&gt;_timer, _callback, 0);
+setup_timer(&amp;_E-&gt;_timer, _callback, (_cast_data)_E);
|
-timer_setup(&amp;_E._timer, _callback, 0);
+setup_timer(&amp;_E._timer, _callback, (_cast_data)&amp;_E);
)

// If we fixed a callback from a .function assignment, fix the
// assignment cast now.
@change_timer_function_assignment
 depends on change_timer_function_usage &amp;&amp;
            (change_callback_handle_cast ||
             change_callback_handle_cast_no_arg ||
             change_callback_handle_arg)@
expression change_timer_function_usage._E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type _cast_func;
typedef TIMER_FUNC_TYPE;
@@

(
 _E-&gt;_timer.function =
-_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-(_cast_func)_callback;
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-(_cast_func)&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-&amp;_callback;
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-(_cast_func)_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-(_cast_func)&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
)

// Sometimes timer functions are called directly. Replace matched args.
@change_timer_function_calls
 depends on change_timer_function_usage &amp;&amp;
            (change_callback_handle_cast ||
             change_callback_handle_cast_no_arg ||
             change_callback_handle_arg)@
expression _E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type _cast_data;
@@

 _callback(
(
-(_cast_data)_E
+&amp;_E-&gt;_timer
|
-(_cast_data)&amp;_E
+&amp;_E._timer
|
-_E
+&amp;_E-&gt;_timer
)
 )

// If a timer has been configured without a data argument, it can be
// converted without regard to the callback argument, since it is unused.
@match_timer_function_unused_data@
expression _E;
identifier _timer;
identifier _callback;
@@

(
-setup_timer(&amp;_E-&gt;_timer, _callback, 0);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, 0L);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, 0UL);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0L);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0UL);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0L);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0UL);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0);
+timer_setup(_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0L);
+timer_setup(_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0UL);
+timer_setup(_timer, _callback, 0);
)

@change_callback_unused_data
 depends on match_timer_function_unused_data@
identifier match_timer_function_unused_data._callback;
type _origtype;
identifier _origarg;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *unused
 )
 {
	... when != _origarg
 }

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Lock around calling a kernel service Rx notification</title>
<updated>2017-11-02T15:07:18+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-11-02T15:06:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=20acbd9a7aeee0b0af7107f3de791a52c949f3ac'/>
<id>20acbd9a7aeee0b0af7107f3de791a52c949f3ac</id>
<content type='text'>
Place a spinlock around the invocation of call-&gt;notify_rx() for a kernel
service call and lock again when ending the call and replace the
notification pointer with a pointer to a dummy function.

This is required because it's possible for rxrpc_notify_socket() to be
called after the call has been ended by the kernel service if called from
the asynchronous work function rxrpc_process_call().

However, rxrpc_notify_socket() currently only holds the RCU read lock when
invoking -&gt;notify_rx(), which means that the afs_call struct would need to
be disposed of by call_rcu() rather than by kfree().

But we shouldn't see any notifications from a call after calling
rxrpc_kernel_end_call(), so a lock is required in rxrpc code.

Without this, we may see the call wait queue as having a corrupt spinlock:

    BUG: spinlock bad magic on CPU#0, kworker/0:2/1612
    general protection fault: 0000 [#1] SMP
    ...
    Workqueue: krxrpcd rxrpc_process_call
    task: ffff88040b83c400 task.stack: ffff88040adfc000
    RIP: 0010:spin_bug+0x161/0x18f
    RSP: 0018:ffff88040adffcc0 EFLAGS: 00010002
    RAX: 0000000000000032 RBX: 6b6b6b6b6b6b6b6b RCX: ffffffff81ab16cf
    RDX: ffff88041fa14c01 RSI: ffff88041fa0ccb8 RDI: ffff88041fa0ccb8
    RBP: ffff88040adffcd8 R08: 00000000ffffffff R09: 00000000ffffffff
    R10: ffff88040adffc60 R11: 000000000000022c R12: ffff88040aca2208
    R13: ffffffff81a58114 R14: 0000000000000000 R15: 0000000000000000
    ....
    Call Trace:
     do_raw_spin_lock+0x1d/0x89
     _raw_spin_lock_irqsave+0x3d/0x49
     ? __wake_up_common_lock+0x4c/0xa7
     __wake_up_common_lock+0x4c/0xa7
     ? __lock_is_held+0x47/0x7a
     __wake_up+0xe/0x10
     afs_wake_up_call_waiter+0x11b/0x122 [kafs]
     rxrpc_notify_socket+0x12b/0x258
     rxrpc_process_call+0x18e/0x7d0
     process_one_work+0x298/0x4de
     ? rescuer_thread+0x280/0x280
     worker_thread+0x1d1/0x2ae
     ? rescuer_thread+0x280/0x280
     kthread+0x12c/0x134
     ? kthread_create_on_node+0x3a/0x3a
     ret_from_fork+0x27/0x40

In this case, note the corrupt data in EBX.  The address of the offending
afs_call is in R12, plus the offset to the spinlock.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Place a spinlock around the invocation of call-&gt;notify_rx() for a kernel
service call and lock again when ending the call and replace the
notification pointer with a pointer to a dummy function.

This is required because it's possible for rxrpc_notify_socket() to be
called after the call has been ended by the kernel service if called from
the asynchronous work function rxrpc_process_call().

However, rxrpc_notify_socket() currently only holds the RCU read lock when
invoking -&gt;notify_rx(), which means that the afs_call struct would need to
be disposed of by call_rcu() rather than by kfree().

But we shouldn't see any notifications from a call after calling
rxrpc_kernel_end_call(), so a lock is required in rxrpc code.

Without this, we may see the call wait queue as having a corrupt spinlock:

    BUG: spinlock bad magic on CPU#0, kworker/0:2/1612
    general protection fault: 0000 [#1] SMP
    ...
    Workqueue: krxrpcd rxrpc_process_call
    task: ffff88040b83c400 task.stack: ffff88040adfc000
    RIP: 0010:spin_bug+0x161/0x18f
    RSP: 0018:ffff88040adffcc0 EFLAGS: 00010002
    RAX: 0000000000000032 RBX: 6b6b6b6b6b6b6b6b RCX: ffffffff81ab16cf
    RDX: ffff88041fa14c01 RSI: ffff88041fa0ccb8 RDI: ffff88041fa0ccb8
    RBP: ffff88040adffcd8 R08: 00000000ffffffff R09: 00000000ffffffff
    R10: ffff88040adffc60 R11: 000000000000022c R12: ffff88040aca2208
    R13: ffffffff81a58114 R14: 0000000000000000 R15: 0000000000000000
    ....
    Call Trace:
     do_raw_spin_lock+0x1d/0x89
     _raw_spin_lock_irqsave+0x3d/0x49
     ? __wake_up_common_lock+0x4c/0xa7
     __wake_up_common_lock+0x4c/0xa7
     ? __lock_is_held+0x47/0x7a
     __wake_up+0xe/0x10
     afs_wake_up_call_waiter+0x11b/0x122 [kafs]
     rxrpc_notify_socket+0x12b/0x258
     rxrpc_process_call+0x18e/0x7d0
     process_one_work+0x298/0x4de
     ? rescuer_thread+0x280/0x280
     worker_thread+0x1d1/0x2ae
     ? rescuer_thread+0x280/0x280
     kthread+0x12c/0x134
     ? kthread_create_on_node+0x3a/0x3a
     ret_from_fork+0x27/0x40

In this case, note the corrupt data in EBX.  The address of the offending
afs_call is in R12, plus the offset to the spinlock.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Allow failed client calls to be retried</title>
<updated>2017-08-29T09:55:20+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-08-29T09:19:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c038a58ccfd6704d4d7d60ed3d6a0fca13cf13a4'/>
<id>c038a58ccfd6704d4d7d60ed3d6a0fca13cf13a4</id>
<content type='text'>
Allow a client call that failed on network error to be retried, provided
that the Tx queue still holds DATA packet 1.  This allows an operation to
be submitted to another server or another address for the same server
without having to repackage and re-encrypt the data so far processed.

Two new functions are provided:

 (1) rxrpc_kernel_check_call() - This is used to find out the completion
     state of a call to guess whether it can be retried and whether it
     should be retried.

 (2) rxrpc_kernel_retry_call() - Disconnect the call from its current
     connection, reset the state and submit it as a new client call to a
     new address.  The new address need not match the previous address.

A call may be retried even if all the data hasn't been loaded into it yet;
a partially constructed will be retained at the same point it was at when
an error condition was detected.  msg_data_left() can be used to find out
how much data was packaged before the error occurred.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Allow a client call that failed on network error to be retried, provided
that the Tx queue still holds DATA packet 1.  This allows an operation to
be submitted to another server or another address for the same server
without having to repackage and re-encrypt the data so far processed.

Two new functions are provided:

 (1) rxrpc_kernel_check_call() - This is used to find out the completion
     state of a call to guess whether it can be retried and whether it
     should be retried.

 (2) rxrpc_kernel_retry_call() - Disconnect the call from its current
     connection, reset the state and submit it as a new client call to a
     new address.  The new address need not match the previous address.

A call may be retried even if all the data hasn't been loaded into it yet;
a partially constructed will be retained at the same point it was at when
an error condition was detected.  msg_data_left() can be used to find out
how much data was packaged before the error occurred.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Cache the congestion window setting</title>
<updated>2017-06-14T19:42:45+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-06-14T16:56:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f7aec129a356ad049edddcb7e77b04a474fcf41f'/>
<id>f7aec129a356ad049edddcb7e77b04a474fcf41f</id>
<content type='text'>
Cache the congestion window setting that was determined during a call's
transmission phase when it finishes so that it can be used by the next call
to the same peer, thereby shortcutting the slow-start algorithm.

The value is stored in the rxrpc_peer struct and is accessed without
locking.  Each call takes the value that happens to be there when it starts
and just overwrites the value when it finishes.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cache the congestion window setting that was determined during a call's
transmission phase when it finishes so that it can be used by the next call
to the same peer, thereby shortcutting the slow-start algorithm.

The value is stored in the rxrpc_peer struct and is accessed without
locking.  Each call takes the value that happens to be there when it starts
and just overwrites the value when it finishes.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Provide a cmsg to specify the amount of Tx data for a call</title>
<updated>2017-06-07T16:15:46+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-06-07T11:40:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e754eba685aac2a9b5538176fa2d254ad25f464d'/>
<id>e754eba685aac2a9b5538176fa2d254ad25f464d</id>
<content type='text'>
Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.

Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.

By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).

An error will be returned if too little or too much data is presented in
the Tx phase.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.

Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.

By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).

An error will be returned if too little or too much data is presented in
the Tx phase.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
