From 9ba4ace39fdfe22268daca9f28c5df384ae462cf Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Wed, 20 Jun 2007 01:07:04 +1000 Subject: [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 Cc: Johannes Berg Signed-off-by: Paul Mackerras --- arch/powerpc/mm/fault.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index bfe90135314..115b25f50bf 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -279,14 +279,13 @@ good_area: #endif /* CONFIG_8xx */ if (is_exec) { -#ifdef CONFIG_PPC64 +#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) /* protection fault */ if (error_code & DSISR_PROTFAULT) goto bad_area; if (!(vma->vm_flags & VM_EXEC)) goto bad_area; -#endif -#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) +#else pte_t *ptep; pmd_t *pmdp; -- cgit v1.2.3