The newly added fixup for buggy dcbX insn's has
a bug that always trigger a kernel TLB walk so a user space
dcbX insn will cause a Kernel Machine Check if it hits DTLB error.
Signed-off-by: Joakim Tjernlund <joakim.tjernl...@transmode.se>
---
I found this problem in 2.4 and forward ported it to 2.6. I
cannot test it so I cannot be 100% sure I got it right.
arch/powerpc/kernel/head_8xx.S | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index ce327c5..91bef6e 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -542,11 +542,11 @@ DARFixed:/* Return from dcbx instruction bug workaround,
r10 holds value of DAR
FixupDAR:/* Entry point for dcbx workaround. */
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
+ andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
DO_8xx_CPU6(0x3780, r3)
mtspr SPRN_MD_EPN, r10
mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */
- cmplwi cr0, r11, 0x0800
- blt- 3f /* Branch if user space */
+ beq- 3f /* Branch if user space */
lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
rlwimi r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */
--
1.6.4.4
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
