linux-toradex.git/lib, branch del-5.8.1.1

Merge commit 'v2.6.35.14' into del-5.8/main

2012-01-19T12:54:23+00:00

Conflicts:
	arch/arm/plat-mxc/include/mach/gpio.h
	arch/x86/kernel/cpu/mtrr/main.c
	drivers/mmc/core/core.c
	drivers/net/smsc911x.c
	fs/proc/task_mmu.c
	include/linux/pm_runtime.h
	mm/memory.c
	mm/mlock.c

Signed-off-by: Alex Gonzalez

debugobjects: Fix boot crash when kmemleak and debugobjects enabled

2011-08-01T20:54:58+00:00

commit 161b6ae0e067e421b20bb35caf66bdb405c929ac upstream.

Order of initialization look like this:
...
debugobjects
kmemleak
...(lots of other subsystems)...
workqueues (through early initcall)
...

debugobjects use schedule_work for batch freeing of its data and kmemleak
heavily use debugobjects, so when it comes to freeing and workqueues were
not initialized yet, kernel crashes:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [] __queue_work+0x29/0x41a
 [] queue_work_on+0x16/0x1d
 [] queue_work+0x29/0x55
 [] schedule_work+0x13/0x15
 [] free_object+0x90/0x95
 [] debug_check_no_obj_freed+0x187/0x1d3
 [] ? _raw_spin_unlock_irqrestore+0x30/0x4d
 [] ? free_object_rcu+0x68/0x6d
 [] kmem_cache_free+0x64/0x12c
 [] free_object_rcu+0x68/0x6d
 [] __rcu_process_callbacks+0x1b6/0x2d9
...

because system_wq is NULL.

Fix it by checking if workqueues susbystem was initialized before using.

Signed-off-by: Marcin Slusarz 
Cc: Catalin Marinas 
Cc: Tejun Heo 
Cc: Dipankar Sarma 
Cc: Paul E. McKenney 
Signed-off-by: Andi Kleen 
Link: http://lkml.kernel.org/r/20110528112342.GA3068@joi.lan
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

rcu: Fix unpaired rcu_irq_enter() from locking selftests

2011-08-01T20:54:51+00:00

commit ba9f207c9f82115aba4ce04b22e0081af0ae300f upstream.

HARDIRQ_ENTER() maps to irq_enter() which calls rcu_irq_enter().
But HARDIRQ_EXIT() maps to __irq_exit() which doesn't call
rcu_irq_exit().

So for every locking selftest that simulates hardirq disabled,
we create an imbalance in the rcu extended quiescent state
internal state.

As a result, after the first missing rcu_irq_exit(), subsequent
irqs won't exit dyntick-idle mode after leaving the interrupt
handler.  This means that RCU won't see the affected CPU as being
in an extended quiescent state, resulting in long grace-period
delays (as in grace periods extending for hours).

To fix this, just use __irq_enter() to simulate the hardirq
context. This is sufficient for the locking selftests as we
don't need to exit any extended quiescent state or perform
any check that irqs normally do when they wake up from idle.

As a side effect, this patch makes it possible to restore
"rcu: Decrease memory-barrier usage based on semi-formal proof",
which eventually helped finding this bug.

Reported-and-tested-by: Yinghai Lu 
Signed-off-by: Frederic Weisbecker 
Cc: Paul E. McKenney 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Andi Kleen

initramfs: Allow using initramfs with empty /dev

2011-05-19T19:20:56+00:00

When booting a kernel with no initramfs, there is a basic /dev hardcoded
in noinitramfs.c.

This contains a /dev/console device. Also, DEVTMPFS can be used to have
the kernel mount a tmpfs /dev and have the devices create nodes on it
when they are added.

When using an initramfs there is no embedded /dev in the kernel, and
the DEVTMPFS is mounted after the sys_open call to /dev/console in
kernel_init. Realistically, the kernel expects the initramfs to contain
a /dev/console node.

This patch reuses Digi specific TMPFSDEV which was used before the
DEVTMPFS support existed to allow for a tmpfs to be mounted in /dev with
a console and a null node so that initramfs with an empty /dev folder
can still boot.

Signed-off-by: Alejandro Gonzalez

mx28evk: Fixed compiler warnings and section mismatches

2011-02-23T19:27:51+00:00

Fixed warnings reported by the compiler and section mismatches reported
by the linker.  This was done as part of the effort to port the mx28evk
from the 2.6.31 kernel to the 2.6.35 kernel.

Signed-off-by: Charles Gordon

init: create some device nodes on boot

2011-01-20T11:40:41+00:00

Mount a TMPFS onto /dev and create console and null device nodes in it.

Signed-off-by: Javier Viguera

radix-tree: fix RCU bug

2010-12-14T22:40:10+00:00

commit 27d20fddc8af539464fc3ba499d6a830054c3bd6 upstream.

Salman Qazi describes the following radix-tree bug:

In the following case, we get can get a deadlock:

0.  The radix tree contains two items, one has the index 0.
1.  The reader (in this case find_get_pages) takes the rcu_read_lock.
2.  The reader acquires slot(s) for item(s) including the index 0 item.
3.  The non-zero index item is deleted, and as a consequence the other item is
    moved to the root of the tree. The place where it used to be is queued for
    deletion after the readers finish.
3b. The zero item is deleted, removing it from the direct slot, it remains in
    the rcu-delayed indirect node.
4.  The reader looks at the index 0 slot, and finds that the page has 0 ref
    count
5.  The reader looks at it again, hoping that the item will either be freed or
    the ref count will increase. This never happens, as the slot it is looking
    at will never be updated. Also, this slot can never be reclaimed because
    the reader is holding rcu_read_lock and is in an infinite loop.

The fix is to re-use the same "indirect" pointer case that requires a slot
lookup retry into a general "retry the lookup" bit.

Signed-off-by: Nick Piggin 
Reported-by: Salman Qazi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Andi Kleen

percpu: fix list_head init bug in __percpu_counter_init()

2010-12-14T22:40:05+00:00

commit 8474b591faf3bb0a1e08a60d21d6baac498f15e4 upstream.

WARNING: at lib/list_debug.c:26 __list_add+0x3f/0x81()
Hardware name: Express5800/B120a [N8400-085]
list_add corruption. next->prev should be prev (ffffffff81a7ea00), but was dead000000200200. (next=ffff88080b872d58).
Modules linked in: aoe ipt_MASQUERADE iptable_nat nf_nat autofs4 sunrpc bridge 8021q garp stp llc ipv6 cpufreq_ondemand acpi_cpufreq freq_table dm_round_robin dm_multipath kvm_intel kvm uinput lpfc scsi_transport_fc igb ioatdma scsi_tgt i2c_i801 i2c_core dca iTCO_wdt iTCO_vendor_support pcspkr shpchp megaraid_sas [last unloaded: aoe]
Pid: 54, comm: events/3 Tainted: G        W  2.6.34-vanilla1 #1
Call Trace:
[] warn_slowpath_common+0x7c/0x94
[] warn_slowpath_fmt+0x41/0x43
[] __list_add+0x3f/0x81
[] __percpu_counter_init+0x59/0x6b
[] bdi_init+0x118/0x17e
[] blk_alloc_queue_node+0x79/0x143
[] blk_alloc_queue+0x11/0x13
[] aoeblk_gdalloc+0x8e/0x1c9 [aoe]
[] aoecmd_sleepwork+0x25/0xa8 [aoe]
[] worker_thread+0x1a9/0x237
[] ? aoecmd_sleepwork+0x0/0xa8 [aoe]
[] ? autoremove_wake_function+0x0/0x39
[] ? worker_thread+0x0/0x237
[] kthread+0x7f/0x87
[] kernel_thread_helper+0x4/0x10
[] ? kthread+0x0/0x87
[] ? kernel_thread_helper+0x0/0x10

It's because there is no initialization code for a list_head contained in
the struct backing_dev_info under CONFIG_HOTPLUG_CPU, and the bug comes up
when block device drivers calling blk_alloc_queue() are used.  In case of
me, I got them by using aoe.

Signed-off-by: Masanori Itoh 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Andi Kleen

lib/list_sort: do not pass bad pointers to cmp callback

2010-10-29T04:51:09+00:00

commit f015ac3edd84ad72f88e08a4d83c56c360aae404 upstream.

If the original list is a POT in length, the first callback from line 73
will pass a==b both pointing to the original list_head.  This is dangerous
because the 'list_sort()' user can use 'container_of()' and accesses the
"containing" object, which does not necessary exist for the list head.  So
the user can access RAM which does not belong to him.  If this is a write
access, we can end up with memory corruption.

Signed-off-by: Don Mullis 
Tested-by: Artem Bityutskiy 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

lmb: rename to memblock

2010-07-14T07:14:00+00:00

via following scripts

      FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

      sed -i \
        -e 's/lmb/memblock/g' \
        -e 's/LMB/MEMBLOCK/g' \
        $FILES

      for N in $(find . -name lmb.[ch]); do
        M=$(echo $N | sed 's/lmb/memblock/g')
        mv $N $M
      done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/

Suggested-by: Ingo Molnar 
Acked-by: "H. Peter Anvin" 
Acked-by: Benjamin Herrenschmidt 
Acked-by: Linus Torvalds 
Signed-off-by: Yinghai Lu 
Signed-off-by: Benjamin Herrenschmidt