linux-stable.git/arch/arm, branch v3.2.19

ARM: 7409/1: Do not call flush_cache_user_range with mmap_sem held

2012-05-30T23:43:49+00:00

commit 435a7ef52db7d86e67a009b36cac1457f8972391 upstream.

We can't be holding the mmap_sem while calling flush_cache_user_range
because the flush can fault. If we fault on a user address, the
page fault handler will try to take mmap_sem again. Since both places
acquire the read lock, most of the time it succeeds. However, if another
thread tries to acquire the write lock on the mmap_sem (e.g. mmap) in
between the call to flush_cache_user_range and the fault, the down_read
in do_page_fault will deadlock.

[will: removed drop of vma parameter as already queued by rmk (7365/1)]

Acked-by: Catalin Marinas 
Signed-off-by: Dima Zavin 
Signed-off-by: John Stultz 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: 7365/1: drop unused parameter from flush_cache_user_range

2012-05-30T23:43:49+00:00

commit 4542b6a0fa6b48d9ae6b41c1efeb618b7a221b2a upstream.

vma isn't used and flush_cache_user_range isn't a standard macro that
is used on several archs with the same prototype. In fact only unicore32
has a macro with the same name (with an identical implementation and no
in-tree users).

This is a part of a patch proposed by Dima Zavin (with Message-id:
1272439931-12795-1-git-send-email-dima@android.com) that didn't get
accepted.

Cc: Dima Zavin 
Acked-by: Catalin Marinas 
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: prevent VM_GROWSDOWN mmaps extending below FIRST_USER_ADDRESS

2012-05-20T21:56:49+00:00

commit 9b61a4d1b2064dbd0c9e61754305ac852170509f upstream.

Reported-by: Al Viro 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: 7417/1: vfp: ensure preemption is disabled when enabling VFP access

2012-05-20T21:56:46+00:00

commit 998de4acb2ba188d20768d1065658377a2e7d29b upstream.

The vfp_enable function enables access to the VFP co-processor register
space (cp10 and cp11) on the current CPU and must be called with
preemption disabled. Unfortunately, the vfp_init late initcall does not
disable preemption and can lead to an oops during boot if thread
migration occurs at the wrong time and we end up attempting to access
the FPSID on a CPU with VFP access disabled.

This patch fixes the initcall to call vfp_enable from a non-preemptible
context on each CPU and adds a BUG_ON(preemptible) to ensure that any
similar problems are easily spotted in the future.

Reported-by: Hyungwoo Yang 
Signed-off-by: Hyungwoo Yang 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: orion5x: Fix GPIO enable bits for MPP9

2012-05-20T21:56:31+00:00

commit 48d99f47a81a66bdd61a348c7fe8df5a7afdf5f3 upstream.

Commit 554cdaefd1cf7bb54b209c4e68c7cec87ce442a9 ('ARM: orion5x: Refactor
mpp code to use common orion platform mpp.') seems to have accidentally
inverted the GPIO valid bits for MPP9 (only).  For the mv2120 platform
which uses MPP9 as a GPIO LED device, this results in the error:

[   12.711476] leds-gpio: probe of leds-gpio failed with error -22

Reported-by: Henry von Tresckow 
References: http://bugs.debian.org/667446
Signed-off-by: Ben Hutchings 
Tested-by: Hans Henry von Tresckow 
Signed-off-by: Jason Cooper

ARM: OMAP: Revert "ARM: OMAP: ctrl: Fix CONTROL_DSIPHY register fields"

2012-05-20T21:56:29+00:00

commit 08ca7444f589bedf9ad5d82883e5d0754852d73b upstream.

This reverts commit 46f8c3c7e95c0d30d95911e7975ddc4f93b3e237.

The commit above swapped the DSI1_PPID and DSI2_PPID register fields in
CONTROL_DSIPHY to be in sync with the newer public OMAP TRMs(after version V).

With this commit, contention errors were reported on DSI lanes some OMAP4 SDPs.
After probing the DSI lanes on OMAP4 SDP, it was seen that setting bits in the
DSI2_PPID field was pulling up voltage on DSI1 lanes, and DSI1_PPID field was
pulling up voltage on DSI2 lanes.

This proves that the current version of OMAP4 TRM is incorrect, swap the
position of register fields according to the older TRM versions as they were
correct.

Acked-by: Tomi Valkeinen 
Signed-off-by: Archit Taneja 
Signed-off-by: Tony Lindgren 
Signed-off-by: Ben Hutchings

ARM: 7414/1: SMP: prevent use of the console when using idmap_pgd

2012-05-11T12:14:59+00:00

commit fde165b2a29673aabf18ceff14dea1f1cfb0daad upstream.

Commit 4e8ee7de227e3ab9a72040b448ad728c5428a042 (ARM: SMP: use
idmap_pgd for mapping MMU enable during secondary booting)
switched secondary boot to use idmap_pgd, which is initialized
during early_initcall, instead of a page table initialized during
__cpu_up.  This causes idmap_pgd to contain the static mappings
but be missing all dynamic mappings.

If a console is registered that creates a dynamic mapping, the
printk in secondary_start_kernel will trigger a data abort on
the missing mapping before the exception handlers have been
initialized, leading to a hang.  Initial boot is not affected
because no consoles have been registered, and resume is usually
not affected because the offending console is suspended.
Onlining a cpu with hotplug triggers the problem.

A workaround is to the printk in secondary_start_kernel until
after the page tables have been switched back to init_mm.

Signed-off-by: Colin Cross 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: 7410/1: Add extra clobber registers for assembly in kernel_execve

2012-05-11T12:14:58+00:00

commit e787ec1376e862fcea1bfd523feb7c5fb43ecdb9 upstream.

The inline assembly in kernel_execve() uses r8 and r9.  Since this
code sequence does not return, it usually doesn't matter if the
register clobber list is accurate.  However, I saw a case where a
particular version of gcc used r8 as an intermediate for the value
eventually passed to r9.  Because r8 is used in the inline
assembly, and not mentioned in the clobber list, r9 was set
to an incorrect value.

This resulted in a kernel panic on execution of the first user-space
program in the system.  r9 is used in ret_to_user as the thread_info
pointer, and if it's wrong, bad things happen.

Signed-off-by: Tim Bird 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQs

2012-05-11T12:14:46+00:00

commit 5e7371ded05adfcfcee44a8bc070bfc37979b8f2 upstream.

When a CPU is hotplugged off, we migrate any IRQs currently affine to it
away and onto another online CPU by calling the irq_set_affinity
function of the relevant interrupt controller chip. This function
returns either IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY, to indicate
whether irq_data.affinity was updated.

If we are forcefully migrating an interrupt (because the affinity mask
no longer identifies any online CPUs) then we should update the IRQ
affinity mask to reflect the new CPU set. Failure to do so can
potentially leave /proc/irq/n/smp_affinity identifying only offline
CPUs, which may confuse userspace IRQ balancing daemons.

This patch updates migrate_one_irq to copy the affinity mask when
the interrupt chip returns IRQ_SET_MASK_OK after forcefully changing the
affinity of an interrupt.

Reported-by: Leif Lindholm 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

ARM: 7403/1: tls: remove covert channel via TPIDRURW

2012-05-11T12:14:46+00:00

commit 6a1c53124aa161eb624ce7b1e40ade728186d34c upstream.

TPIDRURW is a user read/write register forming part of the group of
thread registers in more recent versions of the ARM architecture (~v6+).

Currently, the kernel does not touch this register, which allows tasks
to communicate covertly by reading and writing to the register without
context-switching affecting its contents.

This patch clears TPIDRURW when TPIDRURO is updated via the set_tls
macro, which is called directly from __switch_to. Since the current
behaviour makes the register useless to userspace as far as thread
pointers are concerned, simply clearing the register (rather than saving
and restoring it) will not cause any problems to userspace.

Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings