linux-toradex.git/include/linux, branch v3.4.12

kthread_worker: reimplement flush_kthread_work() to allow freeing the work item being executed

2012-10-02T17:30:40+00:00

commit 46f3d976213452350f9d10b0c2780c2681f7075b upstream.

kthread_worker provides minimalistic workqueue-like interface for
users which need a dedicated worker thread (e.g. for realtime
priority).  It has basic queue, flush_work, flush_worker operations
which mostly match the workqueue counterparts; however, due to the way
flush_work() is implemented, it has a noticeable difference of not
allowing work items to be freed while being executed.

While the current users of kthread_worker are okay with the current
behavior, the restriction does impede some valid use cases.  Also,
removing this difference isn't difficult and actually makes the code
easier to understand.

This patch reimplements flush_kthread_work() such that it uses a
flush_work item instead of queue/done sequence numbers.

Signed-off-by: Tejun Heo 
Cc: Colin Cross 
Signed-off-by: Greg Kroah-Hartman

time: Move ktime_t overflow checking into timespec_valid_strict

2012-10-02T17:30:36+00:00

commit cee58483cf56e0ba355fdd97ff5e8925329aa936 upstream

Andreas Bombe reported that the added ktime_t overflow checking added to
timespec_valid in commit 4e8b14526ca7 ("time: Improve sanity checking of
timekeeping inputs") was causing problems with X.org because it caused
timeouts larger then KTIME_T to be invalid.

Previously, these large timeouts would be clamped to KTIME_MAX and would
never expire, which is valid.

This patch splits the ktime_t overflow checking into a new
timespec_valid_strict function, and converts the timekeeping codes
internal checking to use this more strict function.

Reported-and-tested-by: Andreas Bombe 
Cc: Zhouping Liu 
Cc: Ingo Molnar 
Cc: Prarit Bhargava 
Cc: Thomas Gleixner 
Signed-off-by: John Stultz 
Signed-off-by: Linus Torvalds 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

time: Improve sanity checking of timekeeping inputs

2012-10-02T17:30:36+00:00

commit 4e8b14526ca7fb046a81c94002c1c43b6fdf0e9b upstream.

Unexpected behavior could occur if the time is set to a value large
enough to overflow a 64bit ktime_t (which is something larger then the
year 2262).

Also unexpected behavior could occur if large negative offsets are
injected via adjtimex.

So this patch improves the sanity check timekeeping inputs by
improving the timespec_valid() check, and then makes better use of
timespec_valid() to make sure we don't set the time to an invalid
negative value or one that overflows ktime_t.

Note: This does not protect from setting the time close to overflowing
ktime_t and then letting natural accumulation cause the overflow.

Reported-by: CAI Qian 
Reported-by: Sasha Levin 
Signed-off-by: John Stultz 
Cc: Peter Zijlstra 
Cc: Prarit Bhargava 
Cc: Zhouping Liu 
Cc: Ingo Molnar 
Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

sched: Fix race in task_group()

2012-10-02T17:30:35+00:00

commit 8323f26ce3425460769605a6aece7a174edaa7d1 upstream.

Stefan reported a crash on a kernel before a3e5d1091c1 ("sched:
Don't call task_group() too many times in set_task_rq()"), he
found the reason to be that the multiple task_group()
invocations in set_task_rq() returned different values.

Looking at all that I found a lack of serialization and plain
wrong comments.

The below tries to fix it using an extra pointer which is
updated under the appropriate scheduler locks. Its not pretty,
but I can't really see another way given how all the cgroup
stuff works.

Reported-and-tested-by: Stefan Bader 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1340364965.18025.71.camel@twins
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

NFS: Fix the initialisation of the readdir 'cookieverf' array

2012-10-02T17:30:19+00:00

commit c3f52af3e03013db5237e339c817beaae5ec9e3a upstream.

When the NFS_COOKIEVERF helper macro was converted into a static
inline function in commit 99fadcd764 (nfs: convert NFS_*(inode)
helpers to static inline), we broke the initialisation of the
readdir cookies, since that depended on doing a memset with an
argument of 'sizeof(NFS_COOKIEVERF(inode))' which therefore
changed from sizeof(be32 cookieverf[2]) to sizeof(be32 *).

At this point, NFS_COOKIEVERF seems to be more of an obfuscation
than a helper, so the best thing would be to just get rid of it.

Also see: https://bugzilla.kernel.org/show_bug.cgi?id=46881

Reported-by: Andi Kleen 
Reported-by: David Binderman 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

mm/ia64: fix a memory block size bug

2012-10-02T17:30:05+00:00

commit 05cf96398e1b6502f9e191291b715c7463c9d5dd upstream.

I found following definition in include/linux/memory.h, in my IA64
platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE
will be 0.

  #define MIN_MEMORY_BLOCK_SIZE     (1 << SECTION_SIZE_BITS)

Because MIN_MEMORY_BLOCK_SIZE is int type and length of 32bits,
so MIN_MEMORY_BLOCK_SIZE(1 << 32) will will equal to 0.
Actually when SECTION_SIZE_BITS >= 31, MIN_MEMORY_BLOCK_SIZE will be wrong.
This will cause wrong system memory infomation in sysfs.
I think it should be:

  #define MIN_MEMORY_BLOCK_SIZE     (1UL << SECTION_SIZE_BITS)

And "echo offline > memory0/state" will cause following call trace:

  kernel BUG at mm/memory_hotplug.c:885!
  sh[6455]: bugcheck! 0 [1]
  Pid: 6455, CPU 0, comm:                   sh
  psr : 0000101008526030 ifs : 8000000000000fa4 ip  : []    Not tainted (3.6.0-rc1)
  ip is at offline_pages+0x210/0xee0
  Call Trace:
    show_stack+0x80/0xa0
    show_regs+0x640/0x920
    die+0x190/0x2c0
    die_if_kernel+0x50/0x80
    ia64_bad_break+0x3d0/0x6e0
    ia64_native_leave_kernel+0x0/0x270
    offline_pages+0x210/0xee0
    alloc_pages_current+0x180/0x2a0

Signed-off-by: Jianguo Wu 
Signed-off-by: Jiang Liu 
Cc: "Luck, Tony" 
Reviewed-by: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

kobject: fix oops with "input0: bad kobj_uevent_env content in show_uevent()"

2012-10-02T17:29:55+00:00

commit 60e233a56609fd963c59e99bd75c663d63fa91b6 upstream.

Fengguang Wu  writes:

> After the __devinit* removal series, I can still get kernel panic in
> show_uevent(). So there are more sources of bug..
>
> Debug patch:
>
> @@ -343,8 +343,11 @@ static ssize_t show_uevent(struct device
>                 goto out;
>
>         /* copy keys to file */
> -       for (i = 0; i < env->envp_idx; i++)
> +       dev_err(dev, "uevent %d env[%d]: %s/.../%s\n", env->buflen, env->envp_idx, top_kobj->name, dev->kobj.name);
> +       for (i = 0; i < env->envp_idx; i++) {
> +               printk(KERN_ERR "uevent %d env[%d]: %s\n", (int)count, i, env->envp[i]);
>                 count += sprintf(&buf[count], "%s\n", env->envp[i]);
> +       }
>
> Oops message, the env[] is again not properly initilized:
>
> [   44.068623] input input0: uevent 61 env[805306368]: input0/.../input0
> [   44.069552] uevent 0 env[0]: (null)

This is a completely different CONFIG_HOTPLUG problem, only
demonstrating another reason why CONFIG_HOTPLUG should go away.  I had a
hard time trying to disable it anyway ;-)

The problem this time is lots of code assuming that a call to
add_uevent_var() will guarantee that env->buflen > 0.  This is not true
if CONFIG_HOTPLUG is unset.  So things like this end up overwriting
env->envp_idx because the array index is -1:

	if (add_uevent_var(env, "MODALIAS="))
		return -ENOMEM;
        len = input_print_modalias(&env->buf[env->buflen - 1],
				   sizeof(env->buf) - env->buflen,
				   dev, 0);

Don't know what the best action is, given that there seem to be a *lot*
of this around the kernel.  This patch "fixes" the problem for me, but I
don't know if it can be considered an appropriate fix.

[ It is the correct fix for now, for 3.7 forcing CONFIG_HOTPLUG to
always be on is the longterm fix, but it's too late for 3.6 and older
kernels to resolve this that way - gregkh ]

Reported-by: Fengguang Wu 
Signed-off-by: Bjørn Mork 
Tested-by: Fengguang Wu 
Signed-off-by: Greg Kroah-Hartman

mmc: card: Skip secure erase on MoviNAND; causes unrecoverable corruption.

2012-10-02T17:29:54+00:00

commit 3550ccdb9d8d350e526b809bf3dd92b550a74fe1 upstream.

For several MoviNAND eMMC parts, there are known issues with secure
erase and secure trim.  For these specific MoviNAND devices, we skip
these operations.

Specifically, there is a bug in the eMMC firmware that causes
unrecoverable corruption when the MMC is erased with MMC_CAP_ERASE
enabled.

References:

http://forum.xda-developers.com/showthread.php?t=1644364
https://plus.google.com/111398485184813224730/posts/21pTYfTsCkB#111398485184813224730/posts/21pTYfTsCkB

Signed-off-by: Ian Chen 
Reviewed-by: Namjae Jeon 
Acked-by: Jaehoon Chung 
Reviewed-by: Linus Walleij 
Signed-off-by: Chris Ball 
Signed-off-by: Greg Kroah-Hartman

perf_event: Switch to internal refcount, fix race with close()

2012-10-02T17:29:54+00:00

commit a6fa941d94b411bbd2b6421ffbde6db3c93e65ab upstream.

Don't mess with file refcounts (or keep a reference to file, for
that matter) in perf_event.  Use explicit refcount of its own
instead.  Deal with the race between the final reference to event
going away and new children getting created for it by use of
atomic_long_inc_not_zero() in inherit_event(); just have the
latter free what it had allocated and return NULL, that works
out just fine (children of siblings of something doomed are
created as singletons, same as if the child of leader had been
created and immediately killed).

Signed-off-by: Al Viro 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20120820135925.GG23464@ZenIV.linux.org.uk
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

vfs: dcache: use DCACHE_DENTRY_KILLED instead of DCACHE_DISCONNECTED in d_kill()

2012-10-02T17:29:51+00:00

commit b161dfa6937ae46d50adce8a7c6b12233e96e7bd upstream.

IBM reported a soft lockup after applying the fix for the rename_lock
deadlock.  Commit c83ce989cb5f ("VFS: Fix the nfs sillyrename regression
in kernel 2.6.38") was found to be the culprit.

The nfs sillyrename fix used DCACHE_DISCONNECTED to indicate that the
dentry was killed.  This flag can be set on non-killed dentries too,
which results in infinite retries when trying to traverse the dentry
tree.

This patch introduces a separate flag: DCACHE_DENTRY_KILLED, which is
only set in d_kill() and makes try_to_ascend() test only this flag.

IBM reported successful test results with this patch.

Signed-off-by: Miklos Szeredi 
Cc: Trond Myklebust 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman