]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
powerpc: Sanitize stack pointer in signal handling code
authorJosh Boyer <jwboyer@linux.vnet.ibm.com>
Wed, 25 Mar 2009 06:23:59 +0000 (06:23 +0000)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Fri, 27 Mar 2009 05:58:24 +0000 (16:58 +1100)
commitefbda86098455da014be849713df6498cefc5a2a
treefb239d51dd521bb2976807eeedfacd17be9b6824
parent82631f5dd114e52239fb3d1e270a49d37c088b46
powerpc: Sanitize stack pointer in signal handling code

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 <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
arch/powerpc/include/asm/processor.h
arch/powerpc/kernel/signal.c
arch/powerpc/kernel/signal.h
arch/powerpc/kernel/signal_32.c
arch/powerpc/kernel/signal_64.c