]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
[POWERPC] PowerPC: Prevent data exception in kernel space (32-bit)
authorSegher Boessenkool <segher@kernel.crashing.org>
Tue, 19 Jun 2007 15:07:04 +0000 (01:07 +1000)
committerPaul Mackerras <paulus@samba.org>
Wed, 20 Jun 2007 12:07:38 +0000 (22:07 +1000)
commit9ba4ace39fdfe22268daca9f28c5df384ae462cf
tree92a4ae33dec7bd3dd08f6d118ffd58a0d5247d5e
parent7c8545e98468c53809fc06788a3b9a34dff05240
[POWERPC] PowerPC: Prevent data exception in kernel space (32-bit)

The "is_exec" branch of the protection check in do_page_fault()
didn't do anything on 32-bit PowerPC.  So if a userland program
jumps to a page with Linux protection flags "---p", all the tests
happily fall through, and handle_mm_fault() is called, which in
turn calls handle_pte_fault(), which calls update_mmu_cache(),
which goes flush the dcache to a page with no access rights.

Boom.

This fixes it.

Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/mm/fault.c