linux-toradex.git/arch/arm/lib, branch v4.8-rc2

ARM: 8306/1: loop_udelay: remove bogomips value limitation

2016-06-22T18:55:12+00:00

Now that we don't support ARMv3 anymore, the loop based delay code can
convert microsecs into number of loops using a 64-bit multiplication
and more precision.

This allows us to lift the hard limit of 3355 on the bogomips value as
loops_per_jiffy may now safely span the full 32-bit range.

Signed-off-by: Nicolas Pitre 
Signed-off-by: Russell King

arm, thp: remove infrastructure for handling splitting PMDs

2016-01-16T01:56:32+00:00

With new refcounting we don't need to mark PMDs splitting.  Let's drop
code to handle this.

pmdp_splitting_flush() is not needed too: on splitting PMD we will do
pmdp_clear_flush() + set_pte_at().  pmdp_clear_flush() will do IPI as
needed for fast_gup.

[arnd@arndb.de: fix unterminated ifdef in header file]
Signed-off-by: Kirill A. Shutemov 
Cc: Sasha Levin 
Cc: Aneesh Kumar K.V 
Cc: Jerome Marchand 
Cc: Vlastimil Babka 
Cc: Andrea Arcangeli 
Cc: Hugh Dickins 
Cc: Dave Hansen 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Vlastimil Babka 
Cc: Steve Capper 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Christoph Lameter 
Cc: David Rientjes 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branches 'misc' and 'misc-rc6' into for-linus

2016-01-05T11:07:28+00:00

ARM: 8477/1: runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()

2015-12-17T10:29:01+00:00

The ARM compiler inserts calls to __aeabi_idiv() and
__aeabi_uidiv() when it needs to perform division on signed and
unsigned integers. If a processor has support for the sdiv and
udiv instructions, the kernel may overwrite the beginning of those
functions with those instructions and a "bx lr" to get better
performance.

To ensure that those functions are aligned to a 32-bit word for easier
patching (which might not always be the case in Thumb mode) and that
the two patched instructions end up in the same cache line, a 8-byte
alignment is enforced when ARM_PATCH_IDIV is selected.

This was heavily inspired by a previous patch from Stephen Boyd.

Signed-off-by: Nicolas Pitre 
Acked-by: Arnd Bergmann 
Signed-off-by: Russell King

ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PAN

2015-12-15T11:51:02+00:00

The uaccess_with_memcpy() code is currently incompatible with the SW
PAN code: it takes locks within the region that we've changed the DACR,
potentially sleeping as a result.  As we do not save and restore the
DACR across co-operative sleep events, can lead to an incorrect DACR
value later in this code path.

Reported-by: Peter Rosin 
Tested-by: Peter Rosin 
Signed-off-by: Russell King

ARM: 8438/1: Add unwinding to __clear_user_std()

2015-10-03T15:36:45+00:00

Add unwinding annotations so that unwinding from this function
works properly.

Signed-off-by: Stephen Boyd 
Signed-off-by: Russell King

Merge branches 'cleanup', 'fixes', 'misc', 'omap-barrier' and 'uaccess' into for-linus

2015-09-03T14:28:37+00:00

ARM: software-based priviledged-no-access support

2015-08-26T19:34:24+00:00

Provide a software-based implementation of the priviledged no access
support found in ARMv8.1.

Userspace pages are mapped using a different domain number from the
kernel and IO mappings.  If we switch the user domain to "no access"
when we enter the kernel, we can prevent the kernel from touching
userspace.

However, the kernel needs to be able to access userspace via the
various user accessor functions.  With the wrapping in the previous
patch, we can temporarily enable access when the kernel needs user
access, and re-disable it afterwards.

This allows us to trap non-intended accesses to userspace, eg, caused
by an inadvertent dereference of the LIST_POISON* values, which, with
appropriate user mappings setup, can be made to succeed.  This in turn
can allow use-after-free bugs to be further exploited than would
otherwise be possible.

Signed-off-by: Russell King

ARM: uaccess: provide uaccess_save_and_enable() and uaccess_restore()

2015-08-25T15:14:43+00:00

Provide uaccess_save_and_enable() and uaccess_restore() to permit
control of userspace visibility to the kernel, and hook these into
the appropriate places in the kernel where we need to access
userspace.

Signed-off-by: Russell King

ARM: 8414/1: __copy_to_user_memcpy: fix mmap semaphore usage

2015-08-18T12:59:59+00:00

The mmap semaphore should not be taken when page faults are disabled.
Since pagefault_disable() no longer disables preemption, we now need
to use faulthandler_disabled() in place of in_atomic().

Signed-off-by: Nicolas Pitre 
Tested-by: Mark Salter 
Signed-off-by: Russell King