Add clock support for Vybrid VF610. It uses dtc macro support to
define all clock IDs in vf610-clock.h to keep clock IDs coherence
between kernel and DT.
On some platforms such as VF610, offset of mux and pad ctrl register
may be zero, and the mux_mode and config_val are in one 32-bit register.
This patch adds support to imx core pinctrl framework to handle these
cases.
mmc: sdhci: request irq after sdhci_init() is called
Generally request_irq() should be called after hardware has been
initialized into a sane state. However, sdhci driver currently calls
request_irq() before sdhci_init(). At least, the following kernel panic
seen on i.MX6 is caused by that. The sdhci controller on i.MX6 may have
noisy glitch on DAT1 line, which will trigger SDIO interrupt handling
once request_irq() is called. But at this point, the SDIO interrupt
handler host->sdio_irq_thread has not been registered yet. Thus, we
see the NULL pointer access with wake_up_process(host->sdio_irq_thread)
in mmc_signal_sdio_irq().
sdhci-pltfm: SDHCI platform and OF driver helper
mmc0: no vqmmc regulator found
mmc0: no vmmc regulator found
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = 80004000
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0+ #3
task: 9f860000 ti: 9f862000 task.ti: 9f862000
PC is at wake_up_process+0xc/0x44
LR is at sdhci_irq+0x378/0x93c
...
Backtrace:
[<8004f75c>] (wake_up_process+0x0/0x44) from [<803fb698>]
(sdhci_irq+0x378/0x93c)
r4:9fa68000 r3:00000001
[<803fb320>] (sdhci_irq+0x0/0x93c) from [<80075154>]
(handle_irq_event_percpu+0x54/0x19c)
[<80075100>] (handle_irq_event_percpu+0x0/0x19c) from [<800752ec>]
(handle_irq_event+0x50/0x70)
[<8007529c>] (handle_irq_event+0x0/0x70) from [<80078324>]
(handle_fasteoi_irq+0x9c/0x170)
r5:00000001 r4:9f807900
[<80078288>] (handle_fasteoi_irq+0x0/0x170) from [<80074ac0>]
(generic_handle_irq+0x28/0x38)
r5:8071fd64 r4:00000036
[<80074a98>] (generic_handle_irq+0x0/0x38) from [<8000ee34>]
(handle_IRQ+0x54/0xb4)
r4:8072ab78 r3:00000140
[<8000ede0>] (handle_IRQ+0x0/0xb4) from [<80008600>]
(gic_handle_irq+0x30/0x64)
r8:00000036 r7:a080e100 r6:9f863cd0 r5:8072acbc r4:a080e10c
r3:00000000
[<800085d0>] (gic_handle_irq+0x0/0x64) from [<8000e0c0>]
(__irq_svc+0x40/0x54)
...
---[ end trace e9af3588936b63f0 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Fix the panic by simply reverse the calling sequence between
request_irq() and sdhci_init().
Instead of explicitly calling clock initialization functions, we can
declare the functions with CLK_OF_DECLARE() and then call common
of_clk_init() to have them invoked properly.
Add clock support for i.MX6 SoloLite. It uses the dtc marco support to
define all clock IDs in imx6sl-clock.h, which will be included by both
clock driver and device tree sources, so that the data will stay sync
all the time between kernel and DT.
Currently clock providers defined in the DT are not registered
on i.MX5 platforms since of_clk_init() is not called.
This is not a problem for the SOC's own clocks, which are registered
in code, but prevents the DT being used to define clocks for external
hardware.
Fix this by calling of_clk_init() and actually using the DT to obtain
the 4 SOC fixed clocks.
These are already defined in the DT but were previously just used to
manually obtain the rate.
Fall back to the old scheme for non DT platforms.
Since the same method may be useful for other i.MX platforms
implement the imx_obtain_fixed_clock() function in common code.
Actually changing other i.MX platforms to use this should be done
later by someone with access to the appropriate hardware.
The mxc_arch_reset_init() uses static mapping and calls clk_get_sys() to
get clock. It's suitable for non-DT boot but not for DT boot where
dynamic mapping and of_clk_get() should be used instead. Create
mxc_arch_reset_init_dt() as the DT variant of mxc_arch_reset_init(),
and change DT platforms to use it.
It's inappropriate to call clk_prepare() in mxc_restart(), because the
restart routine could be called in atomic context. Move clk_get() and
clk_prepare() into mxc_arch_reset_init() and only have the atomic part
clk_enable() be called in mxc_restart().
As a result, mxc_arch_reset_init() needs to be called after clk gets
initialized.
While there, it also changes printk(KERN_ERR ...) to pr_err() and adds
__init annotation for mxc_arch_reset_init().
If the current rate of parent clock is sufficient to provide child a
requested rate with a proper divider setting, the rate change request
should not be propagated. Instead, changing the divider setting is good
enough to get child clock run at the requested rate.
On an imx6q clock configuration illustrated below,
ahb --> ipg --> ipg_per
132M 66M 66M
calling clk_set_rate(ipg_per, 22M) with the current
clk_divider_bestdiv() implementation will result in the rate change up
to ahb level like the following, because of the unnecessary/incorrect
rate change propagation.
ahb --> ipg --> ipg_per
66M 22M 22M
Fix the problem by trying to see if the requested rate can be achieved
by simply changing the divider value, and in that case return the
divider immediately from function clk_divider_bestdiv() as the best
one, so that all those unnecessary rate change propagation can be saved.
Type SETUP_PCI, added by setup_efi_pci(), may advertise a ROM size
larger than early_memremap() is able to handle, which is currently
limited to 256kB. If this occurs it leads to a NULL dereference in
parse_setup_data().
To avoid this, remap the setup_data header and allow parsing functions
for individual types to handle their own data remapping.
Signed-off-by: Linn Crosetto <linn@hp.com> Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com Acked-by: Yinghai Lu <yinghai@kernel.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes a race in both msgrcv() and msgsnd() between finding the msg
and actually dealing with the queue, as another thread can delete shmid
underneath us if we are preempted before acquiring the
kern_ipc_perm.lock.
Manfred illustrates this nicely:
Assume a preemptible kernel that is preempted just after
msq = msq_obtain_object_check(ns, msqid)
in do_msgrcv(). The only lock that is held is rcu_read_lock().
Now the other thread processes IPC_RMID. When the first task is
resumed, then it will happily wait for messages on a deleted queue.
Fix this by checking for if the queue has been deleted after taking the
lock.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reported-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 0a2b9d4c7967 ("ipc/sem.c: move wake_up_process out of the
spinlock section"), the update of semaphore's sem_otime(last semop time)
was moved to one central position (do_smart_update).
But since do_smart_update() is only called for operations that modify
the array, this means that wait-for-zero semops do not update sem_otime
anymore.
The fix is simple:
Non-alter operations must update sem_otime.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reported-by: Jia He <jiakernel@gmail.com> Tested-by: Jia He <jiakernel@gmail.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The proc interface is not aware of sem_lock(), it instead calls
ipc_lock_object() directly. This means that simple semop() operations
can run in parallel with the proc interface. Right now, this is
uncritical, because the implementation doesn't do anything that requires
a proper synchronization.
But it is dangerous and therefore should be fixed.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Operations that need access to the whole array must guarantee that there
are no simple operations ongoing. Right now this is achieved by
spin_unlock_wait(sem->lock) on all semaphores.
If complex_count is nonzero, then this spin_unlock_wait() is not
necessary, because it was already performed in the past by the thread
that increased complex_count and even though sem_perm.lock was dropped
inbetween, no simple operation could have started, because simple
operations cannot start when complex_count is non-zero.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The exclusion of complex operations in sem_lock() is insufficient: after
acquiring the per-semaphore lock, a simple op must first check that
sem_perm.lock is not locked and only after that test check
complex_count. The current code does it the other way around - and that
creates a race. Details are below.
The patch is a complete rewrite of sem_lock(), based in part on the code
from Mike Galbraith. It removes all gotos and all loops and thus the
risk of livelocks.
I have tested the patch (together with the next one) on my i3 laptop and
it didn't cause any problems.
The bug is probably also present in 3.10 and 3.11, but for these kernels
it might be simpler just to move the test of sma->complex_count after
the spin_is_locked() test.
Details of the bug:
Assume:
- sma->complex_count = 0.
- Thread 1: semtimedop(complex op that must sleep)
- Thread 2: semtimedop(simple op).
Pseudo-Trace:
Thread 1: sem_lock(): acquire sem_perm.lock
Thread 1: sem_lock(): check for ongoing simple ops
Nothing ongoing, thread 2 is still before sem_lock().
Thread 1: try_atomic_semop()
<<< preempted.
Thread 2: sem_lock():
static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
int nsops)
{
int locknum;
again:
if (nsops == 1 && !sma->complex_count) {
struct sem *sem = sma->sem_base + sops->sem_num;
/* Lock just the semaphore we are interested in. */
spin_lock(&sem->lock);
/*
* If sma->complex_count was set while we were spinning,
* we may need to look at things we did not lock here.
*/
if (unlikely(sma->complex_count)) {
spin_unlock(&sem->lock);
goto lock_array;
}
<<<<<<<<<
<<< complex_count is still 0.
<<<
<<< Here it is preempted
<<<<<<<<<
Thread 1: try_atomic_semop() returns, notices that it must sleep.
Thread 1: increases sma->complex_count.
Thread 1: drops sem_perm.lock
Thread 2:
/*
* Another process is holding the global lock on the
* sem_array; we cannot enter our critical section,
* but have to wait for the global lock to be released.
*/
if (unlikely(spin_is_locked(&sma->sem_perm.lock))) {
spin_unlock(&sem->lock);
spin_unlock_wait(&sma->sem_perm.lock);
goto again;
}
<<< sem_perm.lock already dropped, thus no "goto again;"
locknum = sops->sem_num;
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, IPC mechanisms do security and auditing related checks under
RCU. However, since security modules can free the security structure,
for example, through selinux_[sem,msg_queue,shm]_free_security(), we can
race if the structure is freed before other tasks are done with it,
creating a use-after-free condition. Manfred illustrates this nicely,
for instance with shared mem and selinux:
-> do_shmat calls rcu_read_lock()
-> do_shmat calls shm_object_check().
Checks that the object is still valid - but doesn't acquire any locks.
Then it returns.
-> do_shmat calls security_shm_shmat (e.g. selinux_shm_shmat)
-> selinux_shm_shmat calls ipc_has_perm()
-> ipc_has_perm accesses ipc_perms->security
This patch delays the freeing of the security structures after all RCU
readers are done. Furthermore it aligns the security life cycle with
that of the rest of IPC - freeing them based on the reference counter.
For situations where we need not free security, the current behavior is
kept. Linus states:
"... the old behavior was suspect for another reason too: having the
security blob go away from under a user sounds like it could cause
various other problems anyway, so I think the old code was at least
_prone_ to bugs even if it didn't have catastrophic behavior."
I have tested this patch with IPC testcases from LTP on both my
quad-core laptop and on a 64 core NUMA server. In both cases selinux is
enabled, and tests pass for both voluntary and forced preemption models.
While the mentioned races are theoretical (at least no one as reported
them), I wanted to make sure that this new logic doesn't break anything
we weren't aware of.
After previous cleanups and optimizations, this function is no longer
heavily used and we don't have a good reason to keep it. Update the few
remaining callers and get rid of it.
As suggested by Andrew, add a generic initial locking scheme used
throughout all sysv ipc mechanisms. Documenting the ids rwsem, how rcu
can be enough to do the initial checks and when to actually acquire the
kern_ipc_perm.lock spinlock.
I found that adding it to util.c was generic enough.
Clean up some of the messy do_shmat() spaghetti code, getting rid of
out_free and out_put_dentry labels. This makes shortening the critical
region of this function in the next patch a little easier to do and read.
With the *_INFO, *_STAT, IPC_RMID and IPC_SET commands already optimized,
deal with the remaining SHM_LOCK and SHM_UNLOCK commands. Take the
shm_perm lock after doing the initial auditing and security checks. The
rest of the logic remains unchanged.
While the INFO cmd doesn't take the ipc lock, the STAT commands do acquire
it unnecessarily. We can do the permissions and security checks only
holding the rcu lock.
Similar to semctl and msgctl, when calling msgctl, the *_INFO and *_STAT
commands can be performed without acquiring the ipc object.
Add a shmctl_nolock() function and move the logic of *_INFO and *_STAT out
of msgctl(). Since we are just moving functionality, this change still
takes the lock and it will be properly lockless in the next patch.
This is the third and final patchset that deals with reducing the amount
of contention we impose on the ipc lock (kern_ipc_perm.lock). These
changes mostly deal with shared memory, previous work has already been
done for semaphores and message queues:
With these patches applied, a custom shm microbenchmark stressing shmctl
doing IPC_STAT with 4 threads a million times, reduces the execution
time by 50%. A similar run, this time with IPC_SET, reduces the
execution time from 3 mins and 35 secs to 27 seconds.
Patches 1-8: replaces blindly taking the ipc lock for a smarter
combination of rcu and ipc_obtain_object, only acquiring the spinlock
when updating.
Patch 9: renames the ids rw_mutex to rwsem, which is what it already was.
Patch 10: is a trivial mqueue leftover cleanup
Patch 11: adds a brief lock scheme description, requested by Andrew.
This patch:
Add shm_obtain_object() and shm_obtain_object_check(), which will allow us
to get the ipc object without acquiring the lock. Just as with other
forms of ipc, these functions are basically wrappers around
ipc_obtain_object*().
The check if the queue is full and adding current to the wait queue of
pending msgsnd() operations (ss_add()) must be atomic.
Otherwise:
- the thread that performs msgsnd() finds a full queue and decides to
sleep.
- the thread that performs msgrcv() first reads all messages from the
queue and then sleeps, because the queue is empty.
- the msgrcv() calls do not perform any wakeups, because the msgsnd()
task has not yet called ss_add().
- then the msgsnd()-thread first calls ss_add() and then sleeps.
Net result: msgsnd() and msgrcv() both sleep forever.
Observed with msgctl08 from ltp with a preemptible kernel.
Fix: Call ipc_lock_object() before performing the check.
The patch also moves security_msg_queue_msgsnd() under ipc_lock_object:
- msgctl(IPC_SET) explicitely mentions that it tries to expunge any
pending operations that are not allowed anymore with the new
permissions. If security_msg_queue_msgsnd() is called without locks,
then there might be races.
- it makes the patch much simpler.
sem_otime contains the time of the last semaphore operation that
completed successfully. Every operation updates this value, thus access
from multiple cpus can cause thrashing.
Therefore the patch replaces the variable with a per-semaphore variable.
The per-array sem_otime is only calculated when required.
No performance improvement on a single-socket i3 - only important for
larger systems.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two places that can contain alter operations:
- the global queue: sma->pending_alter
- the per-semaphore queues: sma->sem_base[].pending_alter.
Since one of the queues must be processed first, this causes an odd
priorization of the wakeups: complex operations have priority over
simple ops.
The patch restores the behavior of linux <=3.0.9: The longest waiting
operation has the highest priority.
This is done by using only one queue:
- if there are complex ops, then sma->pending_alter is used.
- otherwise, the per-semaphore queues are used.
As a side effect, do_smart_update_queue() becomes much simpler: no more
goto logic.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce separate queues for operations that do not modify the
semaphore values. Advantages:
- Simpler logic in check_restart().
- Faster update_queue(): Right now, all wait-for-zero operations are
always tested, even if the semaphore value is not 0.
- wait-for-zero gets again priority, as in linux <=3.0.9
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i3, with 2 cores and with hyperthreading enabled. Interleave 2 in order
use first the full cores. HT partially hides the delay from cacheline
trashing, thus the improvement is "only" 8.7% if 4 threads are running.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enforce that ipc_rcu_alloc returns a cacheline aligned pointer on SMP.
Rationale:
The SysV sem code tries to move the main spinlock into a seperate
cacheline (____cacheline_aligned_in_smp). This works only if
ipc_rcu_alloc returns cacheline aligned pointers. vmalloc and kmalloc
return cacheline algined pointers, the implementation of ipc_rcu_alloc
breaks that.
While the INFO cmd doesn't take the ipc lock, the STAT commands do
acquire it unnecessarily. We can do the permissions and security checks
only holding the rcu lock.
This function now mimics semctl_nolock().
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add msq_obtain_object() and msq_obtain_object_check(), which will allow
us to get the ipc object without acquiring the lock. Just as with
semaphores, these functions are basically wrappers around
ipc_obtain_object*().
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Similar to semctl, when calling msgctl, the *_INFO and *_STAT commands
can be performed without acquiring the ipc object.
Add a msgctl_nolock() function and move the logic of *_INFO and *_STAT
out of msgctl(). This change still takes the lock and it will be
properly lockless in the next patch
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This function currently acquires both the rw_mutex and the rcu lock on
successful lookups, leaving the callers to explicitly unlock them,
creating another two level locking situation.
Make the callers (including those that still use ipcctl_pre_down())
explicitly lock and unlock the rwsem and rcu lock.
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patchset continues the work that began in the sysv ipc semaphore
scaling series, see
https://lkml.org/lkml/2013/3/20/546
Just like semaphores used to be, sysv shared memory and msg queues also
abuse the ipc lock, unnecessarily holding it for operations such as
permission and security checks.
This patchset mostly deals with mqueues, and while shared mem can be
done in a very similar way, I want to get these patches out in the open
first. It also does some pending cleanups, mostly focused on the two
level locking we have in ipc code, taking care of ipc_addid() and
ipcctl_pre_down_nolock() - yes there are still functions that need to be
updated as well.
This patch:
Make all callers explicitly take and release the RCU read lock.
This addresses the two level locking seen in newary(), newseg() and
newqueue(). For the last two, explicitly unlock the ipc object and the
rcu lock, instead of calling the custom shm_unlock and msg_unlock
functions. The next patch will deal with the open coded locking for
->perm.lock
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current test for an attached enabled encoder fails if we have
multiple connectors aliased to the same encoder - both connectors
believe they own the enabled encoder and so we attempt to both enable
and disable DPMS on the encoder, leading to hilarity and an OOPs:
Fixes: igt/kms_flip/dpms-off-confusion Reported-and-tested-by: Wakko Warner <wakko@animx.eu.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68030
Link: http://lkml.kernel.org/r/20130928185023.GA21672@animx.eu.org Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Add regression citation, mention the igt testcase this fixes
and slap a cc: stable on the patch.] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dynamic_dname() is both too much and too little for those - the
output may be well in excess of 64 bytes dynamic_dname() assumes
to be enough (thanks to ashmem feeding really long names to
shmem_file_setup()) and vsnprintf() is an overkill for those
guys.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Colin Cross <ccross@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down
a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto'
constructs, as outlined here:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
Implement a workaround suggested by Jakub Jelinek.
Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Suggested-by: Jakub Jelinek <jakub@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20131015062351.GA4666@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARCompact TRAP_S insn used for breakpoints, commits before exception is
taken (updating architectural PC). So ptregs->ret contains next-PC and
not the breakpoint PC itself. This is different from other restartable
exceptions such as TLB Miss where ptregs->ret has exact faulting PC.
gdb needs to know exact-PC hence ARC ptrace GETREGSET provides for
@stop_pc which returns ptregs->ret vs. EFA depending on the
situation.
However, writing stop_pc (SETREGSET request), which updates ptregs->ret
doesn't makes sense stop_pc doesn't always correspond to that reg as
described above.
This was not an issue so far since user_regs->ret / user_regs->stop_pc
had same value and both writing to ptregs->ret was OK, needless, but NOT
broken, hence not observed.
With gdb "jump", they diverge, and user_regs->ret updating ptregs is
overwritten immediately with stop_pc, which this patch fixes.
Previously, when a signal was registered with SA_SIGINFO, parameters 2
and 3 of the signal handler were written to registers r1 and r2 before
the register set was saved. This led to corruption of these two
registers after returning from the signal handler (the wrong values were
restored).
With this patch, registers are now saved before any parameters are
passed, thus maintaining the processor state from before signal entry.
Some ARC SMP systems lack native atomic R-M-W (LLOCK/SCOND) insns and
can only use atomic EX insn (reg with mem) to build higher level R-M-W
primitives. This includes a SystemC based SMP simulation model.
So rwlocks need to use a protecting spinlock for atomic cmp-n-exchange
operation to update reader(s)/writer count.
The spinlock operation itself looks as follows:
mov reg, 1 ; 1=locked, 0=unlocked
retry:
EX reg, [lock] ; load existing, store 1, atomically
BREQ reg, 1, rety ; if already locked, retry
In single-threaded simulation, SystemC alternates between the 2 cores
with "N" insn each based scheduling. Additionally for insn with global
side effect, such as EX writing to shared mem, a core switch is
enforced too.
Given that, 2 cores doing a repeated EX on same location, Linux often
got into a livelock e.g. when both cores were fiddling with tasklist
lock (gdbserver / hackbench) for read/write respectively as the
sequence diagram below shows:
| LTP tests syscalls/process_vm_readv01 and process_vm_writev01 fail
| similarly in one testcase test_iov_invalid -> lvec->iov_base.
| Testcase expects errno EFAULT and return code -1,
| but it gets return code 1 and ERRNO is 0 what means success.
Essentially test case was passing a pointer of -1 which access_ok()
was not catching. It was doing [@addr + @sz <= TASK_SIZE] which would
pass for @addr == -1
Fixed that by rewriting as [@addr <= TASK_SIZE - @sz]
Cast usecs to u64, to ensure that the (usecs * 4295 * HZ)
multiplication is 64 bit.
Initially, the (usecs * 4295 * HZ) part was done as a 32 bit
multiplication, with the result casted to 64 bit. This led to some bits
falling off, causing a "DMA initialization error" in the stmmac Ethernet
driver, due to a premature timeout.
Commit 05b016ecf5e7a "ARC: Setup Vector Table Base in early boot" moved
the Interrupt vector Table setup out of arc_init_IRQ() which is called
for all CPUs, to entry point of boot cpu only, breaking booting of others.
Fix by adding the same to entry point of non-boot CPUs too.
read_arc_build_cfg_regs() printing IVT Base Register didn't help the
casue since it prints a synthetic value if zero which is totally bogus,
so fix that to print the exact Register.
[vgupta: Remove the now stale comment from header of arc_init_IRQ and
also added the commentary for halt-on-reset]
Otherwise early boot exceptions such as instructions errors due to
configuration mismatch between kernel and hardware go off to la-la land,
as opposed to hitting the handler and panic()'ing properly.
Running an "echo t > /proc/sysrq-trigger" crashes the parisc kernel. The
problem is, that in print_worker_info() we try to read the workqueue info via
the probe_kernel_read() functions which use pagefault_disable() to avoid
crashes like this:
probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq));
probe_kernel_read(&wq, &pwq->wq, sizeof(wq));
probe_kernel_read(name, wq->name, sizeof(name) - 1);
The problem here is, that the first probe_kernel_read(&pwq) might return zero
in pwq and as such the following probe_kernel_reads() try to access contents of
the page zero which is read protected and generate a kernel segfault.
With this patch we fix the interruption handler to call parisc_terminate()
directly only if pagefault_disable() was not called (in which case
preempt_count()==0). Otherwise we hand over to the pagefault handler which
will try to look up the faulting address in the fixup tables.
Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes a typo in the code that saves the guest DSCR (Data Stream
Control Register) into the kvm_vcpu_arch struct on guest exit. The
effect of the typo was that the DSCR value was saved in the wrong place,
so changes to the DSCR by the guest didn't persist across guest exit
and entry, and some host kernel memory got corrupted.
Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If we take the 2nd retry path in ext4_expand_extra_isize_ea, we
potentionally return from the function without having freed these
allocations. If we don't do the return, we over-write the previous
allocation pointers, so we leak either way.
Spotted with Coverity.
[ Fixed by tytso to set is and bs to NULL after freeing these
pointers, in case in the retry loop we later end up triggering an
error causing a jump to cleanup, at which point we could have a double
free bug. -- Ted ]
Signed-off-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
btrfs_rename was using the root of the old dir instead of the root of the new
dir when checking for a hash collision, so if you tried to move a file into a
subvol it would freak out because it would see the file you are trying to move
in its current root. This fixes the bug where this would fail
The crash reported and investigated in commit 5f4513 turned out to be
caused by a change to the read interface on newer (2012) SMCs.
Tests by Chris show that simply reading the data valid line is enough
for the problem to go away. Additional tests show that the newer SMCs
no longer wait for the number of requested bytes, but start sending
data right away. Apparently the number of bytes to read is no longer
specified as before, but instead found out by reading until end of
data. Failure to read until end of data confuses the state machine,
which eventually causes the crash.
As a remedy, assuming bit0 is the read valid line, make sure there is
nothing more to read before leaving the read function.
Tested to resolve the original problem, and runtested on MBA3,1,
MBP4,1, MBP8,2, MBP10,1, MBP10,2. The patch seems to have no effect on
machines before 2012.
Tested-by: Chris Murphy <chris@cmurf.com> Signed-off-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Initially commit cb527ede1bf6ff2008a025606f25344b8ed7b4ac
"i2c-omap: Double clear of ARDY status in IRQ handler"
added a workaround for undocumented errata ProDB0017052.
But then commit 1d7afc95946487945cc7f5019b41255b72224b70
"i2c: omap: ack IRQ in parts" refactored code and missed
one of ARDY clearings. So current code violates errata.
It causes often i2c bus timeouts on my Pandaboard.
Olga reported that file descriptors opened with O_PATH do not work with
fstatfs(), found during further development of ksh93's thread support.
There is no reason to not allow O_PATH file descriptors here (fstatfs is
very much a path operation), so use "fdget_raw()". See commit 55815f70147d ("vfs: make O_PATH file descriptors usable for 'fstat()'")
for a very similar issue reported for fstat() by the same team.
Reported-and-tested-by: ольга крыжановская <olga.kryzhanovska@gmail.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason. So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.
The external mic showed up with a precense detect of "always present",
essentially disabling the internal mic. Therefore turn off presence
detection for this pin.
Note: The external mic seems not yet working, but an internal mic is
certainly better than no mic at all.
Currently hdmi_setup_audio_infoframe() reprograms the HDA channel
mapping only when the infoframe is not up-to-date or the non-PCM flag
has changed.
However, when just the channel map has been changed, the infoframe may
still be up-to-date and non-PCM flag may not have changed, so the new
channel map is not actually programmed into the HDA codec.
Notably, this failing case is also always triggered when the device is
already in a prepared state and a new channel map is configured while
changing only the channel positions (for example, plain
"speaker-test -c2 -m FR,FL").
Fix that by always programming the channel map in
hdmi_setup_audio_infoframe(). Tested on Intel HDMI.
Commit c0f04d88e46d ("bcache: Fix flushes in writeback mode") was fixing
a reported data corruption bug, but it seems some last minute
refactoring or rebasing introduced a null pointer deref.
Signed-off-by: Kent Overstreet <kmo@daterainc.com> Reported-by: Gabriel de Perthuis <g2p.code@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adding the device list from the Windows driver description files
included with a new Qualcomm MDM9615 based device, "Alcatel-sbell
ASB TL131 TDD LTE", from China Mobile. This device is tested
and verified to work. The others are assumed to work based on
using the same Windows driver.
Many of these devices support multiple QMI/wwan ports, requiring
multiple interface matching entries. All devices are composite,
providing a mix of one or more serial, storage or Android Debug
Brigde functions in addition to the wwan function.
This device list included an update of one previously known device,
which was incorrectly assumed to have a Gobi 2K layout. This is
corrected.
Reported-by: 王康 <scateu@gmail.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
udev has this nice feature of creating "dead" /dev/<node> device-nodes if
it finds a devnode:<node> modalias. Once the node is accessed, the kernel
automatically loads the module that provides the node. However, this
requires udev to know the major:minor code to use for the node. This
feature was introduced by:
projects / karo-tx-linux.git / log