From ea3cc330ac0cd521ff07c7cd432a1848c19a7e92 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 18 Aug 2009 19:00:34 +0000 Subject: powerpc/mm: Cleanup handling of execute permission This is an attempt at cleaning up a bit the way we handle execute permission on powerpc. _PAGE_HWEXEC is gone, _PAGE_EXEC is now only defined by CPUs that can do something with it, and the myriad of #ifdef's in the I$/D$ coherency code is reduced to 2 cases that hopefully should cover everything. The logic on BookE is a little bit different than what it was though not by much. Since now, _PAGE_EXEC will be set by the generic code for executable pages, we need to filter out if they are unclean and recover it. However, I don't expect the code to be more bloated than it already was in that area due to that change. I could boast that this brings proper enforcing of per-page execute permissions to all BookE and 40x but in fact, we've had that now for some time as a side effect of my previous rework in that area (and I didn't even know it :-) We would only enable execute permission if the page was cache clean and we would only cache clean it if we took and exec fault. Since we now enforce that the later only work if VM_EXEC is part of the VMA flags, we de-fact already enforce per-page execute permissions... Unless I missed something Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/pte-book3e.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'arch/powerpc/include/asm/pte-book3e.h') diff --git a/arch/powerpc/include/asm/pte-book3e.h b/arch/powerpc/include/asm/pte-book3e.h index 1d27c77d7704..9800565aebb8 100644 --- a/arch/powerpc/include/asm/pte-book3e.h +++ b/arch/powerpc/include/asm/pte-book3e.h @@ -37,12 +37,13 @@ #define _PAGE_WRITETHRU 0x800000 /* W: cache write-through */ /* "Higher level" linux bit combinations */ -#define _PAGE_EXEC _PAGE_BAP_SX /* Can be executed from potentially */ -#define _PAGE_HWEXEC _PAGE_BAP_UX /* .. and was cache cleaned */ -#define _PAGE_RW (_PAGE_BAP_SW | _PAGE_BAP_UW) /* User write permission */ -#define _PAGE_KERNEL_RW (_PAGE_BAP_SW | _PAGE_BAP_SR | _PAGE_DIRTY) -#define _PAGE_KERNEL_RO (_PAGE_BAP_SR) -#define _PAGE_USER (_PAGE_BAP_UR | _PAGE_BAP_SR) /* Can be read */ +#define _PAGE_EXEC _PAGE_BAP_UX /* .. and was cache cleaned */ +#define _PAGE_RW (_PAGE_BAP_SW | _PAGE_BAP_UW) /* User write permission */ +#define _PAGE_KERNEL_RW (_PAGE_BAP_SW | _PAGE_BAP_SR | _PAGE_DIRTY) +#define _PAGE_KERNEL_RO (_PAGE_BAP_SR) +#define _PAGE_KERNEL_RWX (_PAGE_BAP_SW | _PAGE_BAP_SR | _PAGE_DIRTY | _PAGE_BAP_SX) +#define _PAGE_KERNEL_ROX (_PAGE_BAP_SR | _PAGE_BAP_SX) +#define _PAGE_USER (_PAGE_BAP_UR | _PAGE_BAP_SR) /* Can be read */ #define _PAGE_HASHPTE 0 #define _PAGE_BUSY 0 -- cgit v1.2.3