ALSA: pcm: fix fifo_size frame calculation

The calculated frame size was wrong because snd_pcm_format_physical_width()
actually returns the number of bits, not bytes.

Use snd_pcm_format_size() instead, which not only returns bytes, but also
simplifies the calculation.

Fixes: 8bea869c5e56 ("ALSA: PCM midlevel: improve fifo_size handling")
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
perf: Fix a race condition in perf_remove_from_context()

We saw a kernel soft lockup in perf_remove_from_context(),
it looks like the `perf` process, when exiting, could not go
out of the retry loop. Meanwhile, the target process was forking
a child. So either the target process should execute the smp
function call to deactive the event (if it was running) or it should
do a context switch which deactives the event.

It seems we optimize out a context switch in perf_event_context_sched_out(),
and what's more important, we still test an obsolete task pointer when
retrying, so no one actually would deactive that event in this situation.
Fix it directly by reloading the task pointer in perf_remove_from_context().

This should cure the above soft lockup.

Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1409696840-843-1-git-send-email-xiyou.wangcong@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
block: Fix dev_t minor allocation lifetime
shmem: fix nlink for rename overwrite directory

If overwriting an empty directory with rename, then need to drop the extra
nlink.

Test prog:

#include <stdio.h>
#include <fcntl.h>
#include <err.h>
#include <sys/stat.h>

int main(void)
{
	const char *test_dir1 = "test-dir1";
	const char *test_dir2 = "test-dir2";
	int res;
	int fd;
	struct stat statbuf;

	res = mkdir(test_dir1, 0777);
	if (res == -1)
		err(1, "mkdir(\"%s\")", test_dir1);

	res = mkdir(test_dir2, 0777);
	if (res == -1)
		err(1, "mkdir(\"%s\")", test_dir2);

	fd = open(test_dir2, O_RDONLY);
	if (fd == -1)
		err(1, "open(\"%s\")", test_dir2);

	res = rename(test_dir1, test_dir2);
	if (res == -1)
		err(1, "rename(\"%s\", \"%s\")", test_dir1, test_dir2);

	res = fstat(fd, &statbuf);
	if (res == -1)
		err(1, "fstat(%i)", fd);

	if (statbuf.st_nlink != 0) {
		fprintf(stderr, "nlink is %lu, should be 0\n", statbuf.st_nlink);
		return 1;
	}

	return 0;
}

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ARM: 8178/1: fix set_tls for !CONFIG_KUSER_HELPERS

Joachim Eastwood reports that commit fbfb872f5f41 "ARM: 8148/1: flush
TLS and thumbee register state during exec" causes a boot-time crash
on a Cortex-M4 nommu system:

Freeing unused kernel memory: 68K (281e5000 - 281f6000)
Unhandled exception: IPSR = 00000005 LR = fffffff1
CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-rc6-00313-gd2205fa30aa7 #191
task: 29834000 ti: 29832000 task.ti: 29832000
PC is at flush_thread+0x2e/0x40
LR is at flush_thread+0x21/0x40
pc : [<2800954a>] lr : [<2800953d>] psr: 4100000b
sp : 29833d60 ip : 00000000 fp : 00000001
r10: 00003cf8 r9 : 29b1f000 r8 : 00000000
r7 : 29b0bc00 r6 : 29834000 r5 : 29832000 r4 : 29832000
r3 : ffff0ff0 r2 : 29832000 r1 : 00000000 r0 : 282121f0
xPSR: 4100000b
CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-rc6-00313-gd2205fa30aa7 #191
[<2800afa5>] (unwind_backtrace) from [<2800a327>] (show_stack+0xb/0xc)
[<2800a327>] (show_stack) from [<2800a963>] (__invalid_entry+0x4b/0x4c)

The problem is that set_tls is attempting to clear the TLS location in
the kernel-user helper page, which isn't set up on V7M.

Fix this by guarding the write to the kuser helper page with
a CONFIG_KUSER_HELPERS ifdef.

Fixes: fbfb872f5f41 ARM: 8148/1: flush TLS and thumbee register state during exec

Reported-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
perf: fix perf bug in fork()

Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by
calling perf_event_free_task() when failing sched_fork() we will not yet
have done the memset() on ->perf_event_ctxp[] and will therefore try and
'free' the inherited contexts, which are still in use by the parent
process.  This is bad..

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: numa: Do not mark PTEs pte_numa when splitting huge pages

This patch reverts 1ba6e0b50b ("mm: numa: split_huge_page: transfer the
NUMA type from the pmd to the pte"). If a huge page is being split due
a protection change and the tail will be in a PROT_NONE vma then NUMA
hinting PTEs are temporarily created in the protected VMA.

 VM_RW|VM_PROTNONE
|-----------------|
      ^
      split here

In the specific case above, it should get fixed up by change_pte_range()
but there is a window of opportunity for weirdness to happen. Similarly,
if a huge page is shrunk and split during a protection update but before
pmd_numa is cleared then a pte_numa can be left behind.

Instead of adding complexity trying to deal with the case, this patch
will not mark PTEs NUMA when splitting a huge page. NUMA hinting faults
will not be triggered which is marginal in comparison to the complexity
in dealing with the corner cases during THP split.

Cc: stable@vger.kernel.org
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: migrate: Close race between migration completion and mprotect
genhd: fix leftover might_sleep() in blk_free_devt()

Commit 2da78092 changed the locking from a mutex to a spinlock,
so we now longer sleep in this context. But there was a leftover
might_sleep() in there, which now triggers since we do the final
free from an RCU callback. Get rid of it.

Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
sched: Fix unreleased llc_shared_mask bit during CPU hotplug

The following bug can be triggered by hot adding and removing a large number of
xen domain0's vcpus repeatedly:

	BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [..] find_busiest_group
	PGD 5a9d5067 PUD 13067 PMD 0
	Oops: 0000 [#3] SMP
	[...]
	Call Trace:
	load_balance
	? _raw_spin_unlock_irqrestore
	idle_balance
	__schedule
	schedule
	schedule_timeout
	? lock_timer_base
	schedule_timeout_uninterruptible
	msleep
	lock_device_hotplug_sysfs
	online_store
	dev_attr_store
	sysfs_write_file
	vfs_write
	SyS_write
	system_call_fastpath

Last level cache shared mask is built during CPU up and the
build_sched_domain() routine takes advantage of it to setup
the sched domain CPU topology.

However, llc_shared_mask is not released during CPU disable,
which leads to an invalid sched domainCPU topology.

This patch fix it by releasing the llc_shared_mask correctly
during CPU disable.

Yasuaki also reported that this can happen on real hardware:

  https://lkml.org/lkml/2014/7/22/1018

His case is here:

	==
	Here is an example on my system.
	My system has 4 sockets and each socket has 15 cores and HT is
	enabled. In this case, each core of sockes is numbered as
	follows:

		 | CPU#
	Socket#0 | 0-14 , 60-74
	Socket#1 | 15-29, 75-89
	Socket#2 | 30-44, 90-104
	Socket#3 | 45-59, 105-119

	Then llc_shared_mask of CPU#30 has 0x3fff80000001fffc0000000.

	It means that last level cache of Socket#2 is shared with
	CPU#30-44 and 90-104.

	When hot-removing socket#2 and #3, each core of sockets is
	numbered as follows:

		 | CPU#
	Socket#0 | 0-14 , 60-74
	Socket#1 | 15-29, 75-89

	But llc_shared_mask is not cleared. So llc_shared_mask of CPU#30
	remains having 0x3fff80000001fffc0000000.

	After that, when hot-adding socket#2 and #3, each core of
	sockets is numbered as follows:

		 | CPU#
	Socket#0 | 0-14 , 60-74
	Socket#1 | 15-29, 75-89
	Socket#2 | 30-59
	Socket#3 | 90-119

	Then llc_shared_mask of CPU#30 becomes
	0x3fff8000fffffffc0000000. It means that last level cache of
	Socket#2 is shared with CPU#30-59 and 90-104. So the mask has
	the wrong value.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Tested-by: Linn Crosetto <linn@hp.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1411547885-48165-1-git-send-email-wanpeng.li@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ecryptfs: avoid to access NULL pointer when write metadata in xattr

Christopher Head 2014-06-28 05:26:20 UTC described:
"I tried to reproduce this on 3.12.21. Instead, when I do "echo hello > foo"
in an ecryptfs mount with ecryptfs_xattr specified, I get a kernel crash:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
PGD d7840067 PUD b2c3c067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in: nvidia(PO)
CPU: 3 PID: 3566 Comm: bash Tainted: P           O 3.12.21-gentoo-r1 #2
Hardware name: ASUSTek Computer Inc. G60JX/G60JX, BIOS 206 03/15/2010
task: ffff8801948944c0 ti: ffff8800bad70000 task.ti: ffff8800bad70000
RIP: 0010:[<ffffffff8110eb39>]  [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
RSP: 0018:ffff8800bad71c10  EFLAGS: 00010246
RAX: 00000000000181a4 RBX: ffff880198648480 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffff880172010450 RDI: 0000000000000000
RBP: ffff880198490e40 R08: 0000000000000000 R09: 0000000000000000
R10: ffff880172010450 R11: ffffea0002c51e80 R12: 0000000000002000
R13: 000000000000001a R14: 0000000000000000 R15: ffff880198490e40
FS:  00007ff224caa700(0000) GS:ffff88019fcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000bb07f000 CR4: 00000000000007e0
Stack:
ffffffff811826e8 ffff8800a39d8000 0000000000000000 000000000000001a
ffff8800a01d0000 ffff8800a39d8000 ffffffff81185fd5 ffffffff81082c2c
00000001a39d8000 53d0abbc98490e40 0000000000000037 ffff8800a39d8220
Call Trace:
[<ffffffff811826e8>] ? ecryptfs_setxattr+0x40/0x52
[<ffffffff81185fd5>] ? ecryptfs_write_metadata+0x1b3/0x223
[<ffffffff81082c2c>] ? should_resched+0x5/0x23
[<ffffffff8118322b>] ? ecryptfs_initialize_file+0xaf/0xd4
[<ffffffff81183344>] ? ecryptfs_create+0xf4/0x142
[<ffffffff810f8c0d>] ? vfs_create+0x48/0x71
[<ffffffff810f9c86>] ? do_last.isra.68+0x559/0x952
[<ffffffff810f7ce7>] ? link_path_walk+0xbd/0x458
[<ffffffff810fa2a3>] ? path_openat+0x224/0x472
[<ffffffff810fa7bd>] ? do_filp_open+0x2b/0x6f
[<ffffffff81103606>] ? __alloc_fd+0xd6/0xe7
[<ffffffff810ee6ab>] ? do_sys_open+0x65/0xe9
[<ffffffff8157d022>] ? system_call_fastpath+0x16/0x1b
RIP  [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
RSP <ffff8800bad71c10>
CR2: 0000000000000000
---[ end trace df9dba5f1ddb8565 ]---"

If we create a file when we mount with ecryptfs_xattr_metadata option, we will
encounter a crash in this path:
->ecryptfs_create
  ->ecryptfs_initialize_file
    ->ecryptfs_write_metadata
      ->ecryptfs_write_metadata_to_xattr
        ->ecryptfs_setxattr
          ->fsstack_copy_attr_all
It's because our dentry->d_inode used in fsstack_copy_attr_all is NULL, and it
will be initialized when ecryptfs_initialize_file finish.

So we should skip copying attr from lower inode when the value of ->d_inode is
invalid.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Cc: stable@vger.kernel.org # v3.2+: b59db43 eCryptfs: Prevent file create race condition
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
fs: make cont_expand_zero interruptible

This patch makes it possible to kill a process looping in
cont_expand_zero. A process may spend a lot of time in this function, so
it is desirable to be able to kill it.

It happened to me that I wanted to copy a piece data from the disk to a
file. By mistake, I used the "seek" parameter to dd instead of "skip". Due
to the "seek" parameter, dd attempted to extend the file and became stuck
doing so - the only possibility was to reset the machine or wait many
hours until the filesystem runs out of space and cont_expand_zero fails.
We need this patch to be able to terminate the process.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
selinux: fix inode security list corruption

sb_finish_set_opts() can race with inode_free_security()
when initializing inode security structures for inodes
created prior to initial policy load or by the filesystem
during ->mount().   This appears to have always been
a possible race, but commit 3dc91d4 ("SELinux:  Fix possible
NULL pointer dereference in selinux_inode_permission()")
made it more evident by immediately reusing the unioned
list/rcu element  of the inode security structure for call_rcu()
upon an inode_free_security().  But the underlying issue
was already present before that commit as a possible use-after-free
of isec.

Shivnandan Kumar reported the list corruption and proposed
a patch to split the list and rcu elements out of the union
as separate fields of the inode_security_struct so that setting
the rcu element would not affect the list element.  However,
this would merely hide the issue and not truly fix the code.

This patch instead moves up the deletion of the list entry
prior to dropping the sbsec->isec_lock initially.  Then,
if the inode is dropped subsequently, there will be no further
references to the isec.

Reported-by: Shivnandan Kumar <shivnandan.k@samsung.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
From: Jeff Moyer <jmoyer@redhat.com>
Date: Tue, 2 Sep 2014 13:17:00 -0400
Subject: aio: add missing smp_rmb() in read_events_ring

commit 2ff396be602f10b5eab8e73b24f20348fa2de159 upstream.

We ran into a case on ppc64 running mariadb where io_getevents would
return zeroed out I/O events.  After adding instrumentation, it became
clear that there was some missing synchronization between reading the
tail pointer and the events themselves.  This small patch fixes the
problem in testing.

Thanks to Zach for helping to look into this, and suggesting the fix.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
cgroup: reject cgroup names with '\n'

commit 71b1fb5c4473a5b1e601d41b109bdfe001ec82e0 upstream.

/proc/<pid>/cgroup contains one cgroup path on each line. If cgroup names are
allowed to contain "\n", applications cannot parse /proc/<pid>/cgroup safely.

Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
[bwh: Backported to 3.2:
 - Adjust context
 - We have to get the name from the dentry pointer]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ext4: add ext4_iget_normal() which is to be used for dir tree lookups

If there is a corrupted file system which has directory entries that
point at reserved, metadata inodes, prohibit them from being used by
treating them the same way we treat Boot Loader inodes --- that is,
mark them to be bad inodes.  This prohibits them from being opened,
deleted, or modified via chmod, chown, utimes, etc.

In particular, this prevents a corrupted file system which has a
directory entry which points at the journal inode from being deleted
and its blocks released, after which point Much Hilarity Ensues.

Reported-by: Sami Liedes <sami.liedes@iki.fi>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
ext4: fix reservation overflow in ext4_da_write_begin
mnt: Prevent pivot_root from creating a loop in the mount tree
Parameter fix
ipv4: move route garbage collector to work queue