[PATCH] ARM: 2698/1: Enable kernel r/w access to user pages on ARMv6
Patch from Catalin Marinas
cpu_v6_set_pte() sets the kernel access rights to r/o for user
pages (L_PTE_USER) when neither L_PTE_WRITE nor L_PTE_DIRTY are
set. This causes a kernel data abort when writing the TLS value
in the 0xffff0000 page. This patch enables the kernel r/w access.
Signed-off-by: Catalin Marinas
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 0aa73d4..e3d8510 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -132,8 +132,8 @@
* 100x 1 0 1 r/o no acc
* 10x0 1 0 1 r/o no acc
* 1011 0 0 1 r/w no acc
- * 110x 1 1 0 r/o r/o
- * 11x0 1 1 0 r/o r/o
+ * 110x 0 1 0 r/w r/o
+ * 11x0 0 1 0 r/w r/o
* 1111 0 1 1 r/w r/w
*/
ENTRY(cpu_v6_set_pte)
@@ -150,7 +150,7 @@
tst r1, #L_PTE_USER
orrne r2, r2, #AP1 | nG
tstne r2, #APX
- eorne r2, r2, #AP0
+ bicne r2, r2, #APX | AP0
tst r1, #L_PTE_YOUNG
biceq r2, r2, #APX | AP1 | AP0