linux-toradex.git/include/linux, branch v3.2.63

slab/mempolicy: always use local policy from interrupt context

2014-09-13T22:41:50+00:00

commit e7b691b085fda913830e5280ae6f724b2a63c824 upstream.

slab_node() could access current->mempolicy from interrupt context.
However there's a race condition during exit where the mempolicy
is first freed and then the pointer zeroed.

Using this from interrupts seems bogus anyways. The interrupt
will interrupt a random process and therefore get a random
mempolicy. Many times, this will be idle's, which noone can change.

Just disable this here and always use local for slab
from interrupts. I also cleaned up the callers of slab_node a bit
which always passed the same argument.

I believe the original mempolicy code did that in fact,
so it's likely a regression.

v2: send version with correct logic
v3: simplify. fix typo.
Reported-by: Arun Sharma 
Cc: penberg@kernel.org
Cc: cl@linux.com
Signed-off-by: Andi Kleen 
[tdmackey@twitter.com: Rework control flow based on feedback from
cl@linux.com, fix logic, and cleanup current task_struct reference]
Acked-by: David Rientjes 
Acked-by: Christoph Lameter 
Acked-by: KOSAKI Motohiro 
Signed-off-by: David Mackey 
Signed-off-by: Pekka Enberg 
Signed-off-by: Ben Hutchings

mnt: Change the default remount atime from relatime to the existing value

2014-09-13T22:41:41+00:00

commit ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e upstream.

Since March 2009 the kernel has treated the state that if no
MS_..ATIME flags are passed then the kernel defaults to relatime.

Defaulting to relatime instead of the existing atime state during a
remount is silly, and causes problems in practice for people who don't
specify any MS_...ATIME flags and to get the default filesystem atime
setting.  Those users may encounter a permission error because the
default atime setting does not work.

A default that does not work and causes permission problems is
ridiculous, so preserve the existing value to have a default
atime setting that is always guaranteed to work.

Using the default atime setting in this way is particularly
interesting for applications built to run in restricted userspace
environments without /proc mounted, as the existing atime mount
options of a filesystem can not be read from /proc/mounts.

In practice this fixes user space that uses the default atime
setting on remount that are broken by the permission checks
keeping less privileged users from changing more privileged users
atime settings.

Acked-by: Serge E. Hallyn 
Signed-off-by: "Eric W. Biederman" 
[bwh: Backported to 3.2: add definition of MNT_ATIME_MASK, as we don't
 need the fix that introduced that definition upstream]
Signed-off-by: Ben Hutchings

libata: introduce ata_host->n_tags to avoid oops on SAS controllers

2014-08-06T17:07:42+00:00

commit 1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 upstream.

1871ee134b73 ("libata: support the ata host which implements a queue
depth less than 32") directly used ata_port->scsi_host->can_queue from
ata_qc_new() to determine the number of tags supported by the host;
unfortunately, SAS controllers doing SATA don't initialize ->scsi_host
leading to the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
 IP: [] ata_qc_new_init+0x188/0x1b0
 PGD 0
 Oops: 0002 [#1] SMP
 Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm
 CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62
 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000
 RIP: 0010:[]  [] ata_qc_new_init+0x188/0x1b0
 RSP: 0018:ffff88061a003ae8  EFLAGS: 00010012
 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa
 RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298
 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200
 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000
 FS:  00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0
 Stack:
  ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200
  ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68
  ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80
 Call Trace:
  [] ata_sas_queuecmd+0xa1/0x430
  [] sas_queuecommand+0x191/0x220 [libsas]
  [] scsi_dispatch_cmd+0x10e/0x300
  [] scsi_request_fn+0x2f5/0x550
  [] __blk_run_queue+0x33/0x40
  [] queue_unplugged+0x2a/0x90
  [] blk_flush_plug_list+0x1b4/0x210
  [] blk_finish_plug+0x14/0x50
  [] __do_page_cache_readahead+0x198/0x1f0
  [] force_page_cache_readahead+0x31/0x50
  [] page_cache_sync_readahead+0x3e/0x50
  [] generic_file_read_iter+0x496/0x5a0
  [] blkdev_read_iter+0x37/0x40
  [] new_sync_read+0x7e/0xb0
  [] vfs_read+0x94/0x170
  [] SyS_read+0x46/0xb0
  [] ? SyS_lseek+0x91/0xb0
  [] system_call_fastpath+0x16/0x1b
 Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 <89> 14 25 58 00 00 00

Fix it by introducing ata_host->n_tags which is initialized to
ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to
scsi_host_template->can_queue in ata_host_register() for !SAS ones.
As SAS hosts are never registered, this will give them the same
ATA_MAX_QUEUE - 1 as before.  Note that we can't use
scsi_host->can_queue directly for SAS hosts anyway as they can go
higher than the libata maximum.

Signed-off-by: Tejun Heo 
Reported-by: Mike Qiu 
Reported-by: Jesse Brandeburg 
Reported-by: Peter Hurley 
Reported-by: Peter Zijlstra 
Tested-by: Alexey Kardashevskiy 
Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32")
Cc: Kevin Hao 
Cc: Dan Williams 
Signed-off-by: Ben Hutchings

introduce SIZE_MAX

2014-08-06T17:07:42+00:00

commit a3860c1c5dd1137db23d7786d284939c5761d517 upstream.

ULONG_MAX is often used to check for integer overflow when calculating
allocation size.  While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.

This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.

Signed-off-by: Xi Wang 
Acked-by: Alex Elder 
Cc: David Airlie 
Cc: Pekka Enberg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

include/linux/math64.h: add div64_ul()

2014-08-06T17:07:37+00:00

commit c2853c8df57f49620d26f317d7d43347c29bfc2e upstream.

There is div64_long() to handle the s64/long division, but no mocro do
u64/ul division.  It is necessary in some scenarios, so add this
function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alex Shi 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

usb-storage/SCSI: Add broken_fua blacklist flag

2014-08-06T17:07:33+00:00

commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream.

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern 
Reported-by: Michael Büsch 
Tested-by: Michael Büsch 
Acked-by: James Bottomley 
CC: Matthew Dharm 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2:
 - Adjust context
 - Use sd_printk() not sd_first_printk()]
Signed-off-by: Ben Hutchings

Revert "net: ip, ipv6: handle gso skbs in forwarding path"

2014-08-06T17:07:31+00:00

This reverts commit caa5344994778a2b4725b2d75c74430f76925e4a, which
was commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream.  In 3.2,
the transport header length is not calculated in the forwarding path,
so skb_gso_network_seglen() returns an incorrect result.  We also have
problems due to the local_df flag not being set correctly.

Signed-off-by: Ben Hutchings

skbuff: add an api to orphan frags

2014-07-11T12:33:59+00:00

commit a353e0ce0fd42d8859260666d1e9b10f2abd4698 upstream.

Many places do
       if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))
		skb_copy_ubufs(skb, gfp_mask);
to copy and invoke frag destructors if necessary.
Add an inline helper for this.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ptrace,x86: force IRET path after a ptrace_stop()

2014-07-11T12:33:59+00:00

commit b9cd18de4db3c9ffa7e17b0dc0ca99ed5aa4d43a upstream.

The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values.  That is
very much part of why it's faster than 'iret'.

Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.

However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'.  Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.

Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().

Signed-off-by: Tejun Heo 
Reported-by: Andy Lutomirski 
Acked-by: Oleg Nesterov 
Suggested-by: Linus Torvalds 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

lib/lzo: Update LZO compression to current upstream version

2014-07-11T12:33:53+00:00

commit 8b975bd3f9089f8ee5d7bbfd798537b992bbc7e7 upstream.

This commit updates the kernel LZO code to the current upsteam version
which features a significant speed improvement - benchmarking the Calgary
and Silesia test corpora typically shows a doubled performance in
both compression and decompression on modern i386/x86_64/powerpc machines.

Signed-off-by: Markus F.X.J. Oberhumer 
Signed-off-by: Ben Hutchings