This is a note to let you know that I've just added the patch titled
ARM: 7784/1: mm: ensure SMP alternates assemble to exactly 4 bytes with Thumb-2
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-7784-1-mm-ensure-smp-alternates-assemble-to-exactly-4-bytes-with-thumb-2.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bf3f0f332f76a85ff3a0b393aaded5a8533769c0 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@xxxxxxx>
Date: Mon, 15 Jul 2013 14:26:19 +0100
Subject: ARM: 7784/1: mm: ensure SMP alternates assemble to exactly 4 bytes with Thumb-2
From: Will Deacon <will.deacon@xxxxxxx>
commit bf3f0f332f76a85ff3a0b393aaded5a8533769c0 upstream.
Commit ae8a8b9553bd ("ARM: 7691/1: mm: kill unused TLB_CAN_READ_FROM_L1_CACHE
and use ALT_SMP instead") added early function returns for page table
cache flushing operations on ARMv7 SMP CPUs.
Unfortunately, when targetting Thumb-2, these `mov pc, lr' sequences
assemble to 2 bytes which can lead to corruption of the instruction
stream after code patching.
This patch fixes the alternates to use wide (32-bit) instructions for
Thumb-2, therefore ensuring that the patching code works correctly.
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/mm/proc-v7-2level.S | 2 +-
arch/arm/mm/proc-v7-3level.S | 2 +-
arch/arm/mm/proc-v7.S | 11 ++++++-----
3 files changed, 8 insertions(+), 7 deletions(-)
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -110,7 +110,7 @@ ENTRY(cpu_v7_set_pte_ext)
ARM( str r3, [r0, #2048]! )
THUMB( add r0, r0, #2048 )
THUMB( str r3, [r0] )
- ALT_SMP(mov pc,lr)
+ ALT_SMP(W(nop))
ALT_UP (mcr p15, 0, r0, c7, c10, 1) @ flush_pte
#endif
mov pc, lr
--- a/arch/arm/mm/proc-v7-3level.S
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -73,7 +73,7 @@ ENTRY(cpu_v7_set_pte_ext)
tst r3, #1 << (55 - 32) @ L_PTE_DIRTY
orreq r2, #L_PTE_RDONLY
1: strd r2, r3, [r0]
- ALT_SMP(mov pc, lr)
+ ALT_SMP(W(nop))
ALT_UP (mcr p15, 0, r0, c7, c10, 1) @ flush_pte
#endif
mov pc, lr
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -75,13 +75,14 @@ ENTRY(cpu_v7_do_idle)
ENDPROC(cpu_v7_do_idle)
ENTRY(cpu_v7_dcache_clean_area)
- ALT_SMP(mov pc, lr) @ MP extensions imply L1 PTW
- ALT_UP(W(nop))
- dcache_line_size r2, r3
-1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
+ ALT_SMP(W(nop)) @ MP extensions imply L1 PTW
+ ALT_UP_B(1f)
+ mov pc, lr
+1: dcache_line_size r2, r3
+2: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, r2
subs r1, r1, r2
- bhi 1b
+ bhi 2b
dsb
mov pc, lr
ENDPROC(cpu_v7_dcache_clean_area)
Patches currently in stable-queue which might be from will.deacon@xxxxxxx are
queue-3.10/arm-7791-1-a.out-remove-partial-a.out-support.patch
queue-3.10/arm-7784-1-mm-ensure-smp-alternates-assemble-to-exactly-4-bytes-with-thumb-2.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html