commit bde6c6e16aa489ea76c762fb7ffb0abb48660dd8
author Scott Wood <scottwood@freescale.com> Thu Sep 06 08:04:38 2007 +1000
committer Paul Mackerras <paulus@samba.org> Fri Sep 14 01:33:23 2007 +1000
tree 147f59710f6026c174685758b0d6764fcea12e84
parent 96ebc3bfb6ddedd5a400d5653b50551d5a3de439

[POWERPC] Check _PAGE_RW and _PAGE_PRESENT on kernel addresses

Previously, the TLB miss handlers assumed that pages above KERNELBASE are
always present and read/write.  This assumption is false in the case of
CONFIG_DEBUG_PAGEALLOC.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/head_32.S

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 7d73a13..0e3df1f 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -475,10 +475,10 @@
 	li	r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
 	lwz	r2,PGDIR(r2)
 	blt+	112f
+	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
+	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 	lis	r2,swapper_pg_dir@ha	/* if kernel address, use */
 	addi	r2,r2,swapper_pg_dir@l	/* kernel page table */
-	mfspr	r1,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
-	rlwinm	r1,r1,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 112:	tophys(r2,r2)
 	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */
 	lwz	r2,0(r2)		/* get pmd entry */
@@ -549,10 +549,10 @@
 	li	r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
 	lwz	r2,PGDIR(r2)
 	blt+	112f
+	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
+	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 	lis	r2,swapper_pg_dir@ha	/* if kernel address, use */
 	addi	r2,r2,swapper_pg_dir@l	/* kernel page table */
-	mfspr	r1,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
-	rlwinm	r1,r1,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 112:	tophys(r2,r2)
 	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */
 	lwz	r2,0(r2)		/* get pmd entry */
@@ -621,10 +621,10 @@
 	li	r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
 	lwz	r2,PGDIR(r2)
 	blt+	112f
+	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
+	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 	lis	r2,swapper_pg_dir@ha	/* if kernel address, use */
 	addi	r2,r2,swapper_pg_dir@l	/* kernel page table */
-	mfspr	r1,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
-	rlwinm	r1,r1,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 112:	tophys(r2,r2)
 	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */
 	lwz	r2,0(r2)		/* get pmd entry */