Le 18/12/2014 03:22, Scott Wood a écrit :
On Wed, 2014-12-17 at 10:14 +0100, Christophe Leroy wrote:
On powerpc 8xx, in TLB entries, 0x400 bit is set to 1 for read-only pages
and is set to 0 for RW pages. So we should use _PAGE_RO instead of _PAGE_RW
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
v2 is a complete rework compared to v1
arch/powerpc/include/asm/pte-8xx.h | 7 +++----
arch/powerpc/kernel/head_8xx.S | 3 ---
2 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/pte-8xx.h
b/arch/powerpc/include/asm/pte-8xx.h
index daa4616..4f5583e 100644
--- a/arch/powerpc/include/asm/pte-8xx.h
+++ b/arch/powerpc/include/asm/pte-8xx.h
@@ -46,7 +46,7 @@
* require a TLB exception handler change. It is assumed unused bits
* are always zero.
*/
-#define _PAGE_RW 0x0400 /* lsb PP bits, inverted in HW */
+#define _PAGE_RO 0x0400 /* lsb PP bits */
It looks like pte_update() needs to be updated to match.
#define _PAGE_USER 0x0800 /* msb PP bits */
/* set when neither _PAGE_USER nor _PAGE_RW are set */
Also update this comment.
#define _PAGE_KNLRO 0x0200
@@ -62,9 +62,8 @@
#define PTE_ATOMIC_UPDATES 1
/* We need to add _PAGE_SHARED to kernel pages */
-#define _PAGE_KERNEL_RO (_PAGE_SHARED | _PAGE_KNLRO)
-#define _PAGE_KERNEL_ROX (_PAGE_EXEC | _PAGE_KNLRO)
-#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
+#define _PAGE_KERNEL_RO (_PAGE_SHARED | _PAGE_RO | _PAGE_KNLRO)
+#define _PAGE_KERNEL_ROX (_PAGE_EXEC | _PAGE_RO | _PAGE_KNLRO)
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_PTE_8xx_H */
Where did _PAGE_KERNEL_RW go?
It is already defined like this in pte-common.h:
#ifndef _PAGE_KERNEL_RW
#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
#endif
Christophe
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