linux-toradex.git/arch/powerpc, branch v2.6.27.54

compat: Make compat_alloc_user_space() incorporate the access_ok()

2010-09-20T20:03:21+00:00

commit c41d68a513c71e35a14f66d71782d27a79a81ea6 upstream.

compat_alloc_user_space() expects the caller to independently call
access_ok() to verify the returned area.  A missing call could
introduce problems on some architectures.

This patch incorporates the access_ok() check into
compat_alloc_user_space() and also adds a sanity check on the length.
The existing compat_alloc_user_space() implementations are renamed
arch_compat_alloc_user_space() and are used as part of the
implementation of the new global function.

This patch assumes NULL will cause __get_user()/__put_user() to either
fail or access userspace on all architectures.  This should be
followed by checking the return value of compat_access_user_space()
for NULL in the callers, at which time the access_ok() in the callers
can also be removed.

Reported-by: Ben Hawkes 
Signed-off-by: H. Peter Anvin 
Acked-by: Benjamin Herrenschmidt 
Acked-by: Chris Metcalf 
Acked-by: David S. Miller 
Acked-by: Ingo Molnar 
Acked-by: Thomas Gleixner 
Acked-by: Tony Luck 
Cc: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: James Bottomley 
Cc: Kyle McMartin 
Cc: Martin Schwidefsky 
Cc: Paul Mackerras 
Cc: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

powerpc/oprofile: fix potential buffer overrun in op_model_cell.c

2010-07-05T18:08:43+00:00

commit 238c1a78c957f3dc7cb848b161dcf4805793ed56 upstream.

Fix potential initial_lfsr buffer overrun.
Writing past the end of the buffer could happen when index == ENTRIES

Signed-off-by: Denis Kirjanov 
Signed-off-by: Robert Richter 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Make query_cpu_stopped callable outside hotplug cpu

2010-07-05T18:08:42+00:00

commit f8b67691828321f5c85bb853283aa101ae673130 upstream.

This moves query_cpu_stopped() out of the hotplug cpu code and into
smp.c so it can called in other places and renames it to
smp_query_cpu_stopped().

It also cleans up the return values by adding some #defines

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Only call start-cpu when a CPU is stopped

2010-07-05T18:08:42+00:00

commit aef40e87d866355ffd279ab21021de733242d0d5 upstream.

Currently we always call start-cpu irrespective of if the CPU is
stopped or not. Unfortunatley on POWER7, firmware seems to not like
start-cpu being called when a cpu already been started.  This was not
the case on POWER6 and earlier.

This patch checks to see if the CPU is stopped or not via an
query-cpu-stopped-state call, and only calls start-cpu on CPUs which
are stopped.

This fixes a bug with kexec on POWER7 on PHYP where only the primary
thread would make it to the second kernel.

Reported-by: Ankita Garg 
Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix handling of strncmp with zero len

2010-07-05T18:08:42+00:00

commit 637a99022fb119b90fb281715d13172f0394fc12 upstream.

Commit 0119536c, which added the assembly version of strncmp to
powerpc, mentions that it adds two instructions to the version from
boot/string.S to allow it to handle len=0. Unfortunately, it doesn't
always return 0 when that is the case. The length is passed in r5, but
the return value is passed back in r3. In certain cases, this will
happen to work. Otherwise it will pass back the address of the first
string as the return value.

This patch lifts the len <= 0 handling code from memcpy to handle that
case.

Reported by: Christian_Sellars@symantec.com
Signed-off-by: Jeff Mahoney 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Handle VSX alignment faults correctly in little-endian mode

2010-01-18T18:34:03+00:00

commit bb7f20b1c639606def3b91f4e4aca6daeee5d80a upstream.

This patch fixes the handling of VSX alignment faults in little-endian
mode (the current code assumes the processor is in big-endian mode).

The patch also makes the handlers clear the top 8 bytes of the register
when handling an 8 byte VSX load.

This is based on 2.6.32.

Signed-off-by: Neil Campbell 
Acked-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Disable VSX or current process in giveup_fpu/altivec

2010-01-18T18:34:01+00:00

commit 7e875e9dc8af70d126fa632446e967327ac3fdda upstream.

When we call giveup_fpu, we need to need to turn off VSX for the
current process.  If we don't, on return to userspace it may execute a
VSX instruction before the next FP instruction, and not have its
register state refreshed correctly from the thread_struct.  Ditto for
altivec.

This caused a bug where an unaligned lfs or stfs results in
fix_alignment calling giveup_fpu so it can use the FPRs (in order to
do a single <-> double conversion), and then returning to userspace
with FP off but VSX on.  Then if a VSX instruction is executed, before
another FP instruction, it will proceed without another exception and
hence have the incorrect register state for VSX registers 0-31.

   lfs unaligned   <- alignment exception turns FP off but leaves VSX on

   VSX instruction <- no exception since VSX on, hence we get the
                      wrong VSX register values for VSX registers 0-31,
                      which overlap the FPRs.

Signed-off-by: Michael Neuling 
Signed-off-by: Paul Mackerras 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix to handle slb resize across migration

2009-09-24T15:47:37+00:00

commit 46db2f86a3b2a94e0b33e0b4548fb7b7b6bdff66 upstream.

The SLB can change sizes across a live migration, which was not
being handled, resulting in possible machine crashes during
migration if migrating to a machine which has a smaller max SLB
size than the source machine. Fix this by first reducing the
SLB size to the minimum possible value, which is 32, prior to
migration. Then during the device tree update which occurs after
migration, we make the call to ensure the SLB gets updated. Also
add the slb_size to the lparcfg output so that the migration
tools can check to make sure the kernel has this capability
before allowing migration in scenarios where the SLB size will change.

BenH: Fixed #include  ->  to avoid
      breaking ppc32 build

Signed-off-by: Brian King 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Sanitize stack pointer in signal handling code

2009-05-02T17:24:48+00:00

This has been backported to 2.6.27.x from commit efbda86098 in Linus' tree.

On powerpc64 machines running 32-bit userspace, we can get garbage bits in the
stack pointer passed into the kernel.  Most places handle this correctly, but
the signal handling code uses the passed value directly for allocating signal
stack frames.

This fixes the issue by introducing a get_clean_sp function that returns a
sanitized stack pointer.  For 32-bit tasks on a 64-bit kernel, the stack
pointer is masked correctly.  In all other cases, the stack pointer is simply
returned.

Additionally, we pass an 'is_32' parameter to get_sigframe now in order to
get the properly sanitized stack.  The callers are know to be 32 or 64-bit
statically.

Signed-off-by: Josh Boyer 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix data-corrupting bug in __futex_atomic_op

2009-05-02T17:24:22+00:00

upstream commit: 306a82881b14d950d59e0b59a55093a07d82aa9a

Richard Henderson pointed out that the powerpc __futex_atomic_op has a
bug: it will write the wrong value if the stwcx. fails and it has to
retry the lwarx/stwcx. loop, since 'oparg' will have been overwritten
by the result from the first time around the loop.  This happens
because it uses the same register for 'oparg' (an input) as it uses
for the result.

This fixes it by using separate registers for 'oparg' and 'ret'.

Cc: stable@kernel.org
Signed-off-by: Paul Mackerras 
Signed-off-by: Chris Wright 
Signed-off-by: Greg Kroah-Hartman