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authorWill Deacon <will.deacon@arm.com>2013-07-15 14:26:19 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-07-22 14:29:09 +0100
commitbf3f0f332f76a85ff3a0b393aaded5a8533769c0 (patch)
treec2af37fb279885a29863ec1da7980f16976e8f21 /arch/arm/mm
parentb6992fa9a74862c5addb62cde1657c7479615d86 (diff)
ARM: 7784/1: mm: ensure SMP alternates assemble to exactly 4 bytes with Thumb-2
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. Cc: <stable@vger.kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/proc-v7-2level.S2
-rw-r--r--arch/arm/mm/proc-v7-3level.S2
-rw-r--r--arch/arm/mm/proc-v7.S11
3 files changed, 8 insertions, 7 deletions
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index f64afb9f1bd5..bdd3be4be77a 100644
--- 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
diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S
index c36ac69488c8..01a719e18bb0 100644
--- a/arch/arm/mm/proc-v7-3level.S
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -81,7 +81,7 @@ 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
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 5c6d5a3050ea..73398bcf9bd8 100644
--- 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)