[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>

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 0aa73d414783..e3d8510f4340 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -132,8 +132,8 @@ ENTRY(cpu_v6_switch_mm)
  *        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 @@ ENTRY(cpu_v6_set_pte)
         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