linux.git/include/linux, branch v2.6.35

NFS: Fix a typo in include/linux/nfs_fs.h

2010-08-01T22:10:01+00:00

nfs_commit_inode() needs to be defined irrespectively of whether or not
we are supporting NFSv3 and NFSv4.

Allow the compiler to optimise away code in the NFSv2-only case by
converting it into an inlined stub function.

Reported-and-tested-by: Ingo Molnar 
Signed-off-by: Trond Myklebust 
Signed-off-by: Linus Torvalds

NFS: kswapd must not block in nfs_release_page

2010-07-30T19:38:42+00:00

See https://bugzilla.kernel.org/show_bug.cgi?id=16056

If other processes are blocked waiting for kswapd to free up some memory so
that they can make progress, then we cannot allow kswapd to block on those
processes.

Signed-off-by: Trond Myklebust 
Cc: stable@kernel.org

CRED: Fix __task_cred()'s lockdep check and banner comment

2010-07-29T22:16:18+00:00

Fix __task_cred()'s lockdep check by removing the following validation
condition:

	lockdep_tasklist_lock_is_held()

as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.

Instead, add the following validation condition:

	task->exit_state >= 0

to permit the access if the target task is dead and therefore unable to change
its own credentials.

Fix __task_cred()'s comment to:

 (1) discard the bit that says that the caller must prevent the target task
     from being deleted.  That shouldn't need saying.

 (2) Add a comment indicating the result of __task_cred() should not be passed
     directly to get_cred(), but rather than get_task_cred() should be used
     instead.

Also put a note into the documentation to enforce this point there too.

Signed-off-by: David Howells 
Acked-by: Jiri Olsa 
Cc: Paul E. McKenney 
Signed-off-by: Linus Torvalds

CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials

2010-07-29T22:16:17+00:00

It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.

What happens is that get_task_cred() can race with commit_creds():

	TASK_1			TASK_2			RCU_CLEANER
	-->get_task_cred(TASK_2)
	rcu_read_lock()
	__cred = __task_cred(TASK_2)
				-->commit_creds()
				old_cred = TASK_2->real_cred
				TASK_2->real_cred = ...
				put_cred(old_cred)
				  call_rcu(old_cred)
		[__cred->usage == 0]
	get_cred(__cred)
		[__cred->usage == 1]
	rcu_read_unlock()
							-->put_cred_rcu()
							[__cred->usage == 1]
							panic()

However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.

If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.

We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.

Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:

kernel BUG at kernel/cred.c:168!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 0
Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex
745
RIP: 0010:[]  [] __put_cred+0xc/0x45
RSP: 0018:ffff88019e7e9eb8  EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff
RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0
RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0
R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001
FS:  00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0)
Stack:
 ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45
<0> ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000
<0> ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246
Call Trace:
 [] put_cred+0x13/0x15
 [] commit_creds+0x16b/0x175
 [] set_current_groups+0x47/0x4e
 [] sys_setgroups+0xf6/0x105
 [] system_call_fastpath+0x16/0x1b
Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00
48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 <0f> 0b eb fe 65 48 8b
04 25 00 cc 00 00 48 3b b8 58 04 00 00 75
RIP  [] __put_cred+0xc/0x45
 RSP 
---[ end trace df391256a100ebdd ]---

Signed-off-by: David Howells 
Acked-by: Jiri Olsa 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6

2010-07-29T02:59:55+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  davinci: da850/omap-l138 evm: account for DEFDCDC{2,3} being tied high
  regulator: tps6507x: allow driver to use DEFDCDC{2,3}_HIGH register
  wm8350-regulator: fix wm8350_register_regulator error handling
  ab3100: fix off-by-one value range checking for voltage selector

regulator: tps6507x: allow driver to use DEFDCDC{2,3}_HIGH register

2010-07-28T14:09:26+00:00

Acked-by: Mark Brown 

In TPS6507x, depending on the status of DEFDCDC{2,3} pin either
DEFDCDC{2,3}_LOW or DEFDCDC{2,3}_HIGH register needs to be read or
programmed to change the output voltage.

The current driver assumes DEFDCDC{2,3} pins are always tied low
and thus operates only on DEFDCDC{2,3}_LOW register. This need
not always be the case (as is found on OMAP-L138 EVM).

Unfortunately, software cannot read the status of DEFDCDC{2,3} pins.
So, this information is passed through platform data depending on
how the board is wired.

Signed-off-by: Anuj Aggarwal 
Signed-off-by: Sekhar Nori 
Signed-off-by: Liam Girdwood

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

2010-07-27T16:21:00+00:00

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  s2io: fixing DBG_PRINT() macro
  ath9k: fix dma direction for map/unmap in ath_rx_tasklet
  net: dev_forward_skb should call nf_reset
  net sched: fix race in mirred device removal
  tun: avoid BUG, dump packet on GSO errors
  bonding: set device in RLB ARP packet handler
  wimax/i2400m: Add PID & VID for Intel WiMAX 6250
  ipv6: Don't add routes to ipv6 disabled interfaces.
  net: Fix skb_copy_expand() handling of ->csum_start
  net: Fix corruption of skb csum field in pskb_expand_head() of net/core/skbuff.c
  macvtap: Limit packet queue length
  ixgbe/igb: catch invalid VF settings
  bnx2x: Advance a module version
  bnx2x: Protect statistics ramrod and sequence number
  bnx2x: Protect a SM state change
  wireless: use netif_rx_ni in ieee80211_send_layer2_update

ACPI / Sleep: Allow the NVS saving to be skipped during suspend to RAM

2010-07-25T03:26:09+00:00

Commit 2a6b69765ad794389f2fc3e14a0afa1a995221c2
(ACPI: Store NVS state even when entering suspend to RAM) caused the
ACPI suspend code save the NVS area during suspend and restore it
during resume unconditionally, although it is known that some systems
need to use acpi_sleep=s4_nonvs for hibernation to work.  To allow
the affected systems to avoid saving and restoring the NVS area
during suspend to RAM and resume, introduce kernel command line
option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its
alias temporarily (add acpi_sleep=s4_nonvs to the feature removal
file).

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 .

Signed-off-by: Rafael J. Wysocki 
Reported-and-tested-by: tomas m 
Signed-off-by: Len Brown

macvtap: Limit packet queue length

2010-07-22T20:08:56+00:00

Mark Wagner reported OOM symptoms when sending UDP traffic over
a macvtap link to a kvm receiver.

This appears to be caused by the fact that macvtap packet queues
are unlimited in length.  This means that if the receiver can't
keep up with the rate of flow, then we will hit OOM. Of course
it gets worse if the OOM killer then decides to kill the receiver.

This patch imposes a cap on the packet queue length, in the same
way as the tuntap driver, using the device TX queue length.

Please note that macvtap currently has no way of giving congestion
notification, that means the software device TX queue cannot be
used and packets will always be dropped once the macvtap driver
queue fills up.

This shouldn't be a great problem for the scenario where macvtap
is used to feed a kvm receiver, as the traffic is most likely
external in origin so congestion notification can't be applied
anyway.

Of course, if anybody decides to complain about guest-to-guest
UDP packet loss down the track, then we may have to revisit this.

Incidentally, this patch also fixes a real memory leak when
macvtap_get_queue fails.

Chris Wright noticed that for this patch to work, we need a
non-zero TX queue length.  This patch includes his work to change
the default macvtap TX queue length to 500.

Reported-by: Mark Wagner 
Signed-off-by: Herbert Xu 
Acked-by: Chris Wright 
Acked-by: Arnd Bergmann 
Signed-off-by: David S. Miller

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb

2010-07-22T18:44:26+00:00

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  sysrq,kdb: Use __handle_sysrq() for kdb's sysrq function
  debug_core,kdb: fix kgdb_connected bit set in the wrong place
  Fix merge regression from external kdb to upstream kdb
  repair gdbstub to match the gdbserial protocol specification
  kdb: break out of kdb_ll() when command is terminated