From: Anson Huang <Anson.Huang@xxxxxxxxxxxxx>
3.4.113-rc1 review patch. If anyone has any objections, please let me know.
------------------
commit fa0708b320f6da4c1104fe56e01b7abf66fd16ad upstream.
In cpu_v7_do_suspend routine, r11 is used while it is NOT
saved/restored, different compiler may have different usage
of ARM general registers, so it may cause issues during
calling cpu_v7_do_suspend.
We meet kernel fault occurs when using GCC 4.8.3, r11 contains
valid value before calling into cpu_v7_do_suspend, but when returned
from this routine, r11 is corrupted and lead to kernel fault.
Doing save/restore for those corrupted registers is a must in
assemble code.
Signed-off-by: Anson Huang <Anson.Huang@xxxxxxxxxxxxx>
Reviewed-by: Nicolas Pitre <nico@xxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@xxxxxxxxxx>
---
arch/arm/mm/proc-v7.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index fb489cc..74c3e53 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -94,7 +94,7 @@ ENDPROC(cpu_v7_dcache_clean_area)
.equ cpu_v7_suspend_size, 4 * 8
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v7_do_suspend)
- stmfd sp!, {r4 - r10, lr}
+ stmfd sp!, {r4 - r11, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r5}
@@ -105,7 +105,7 @@ ENTRY(cpu_v7_do_suspend)
mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control
stmia r0, {r6 - r11}
- ldmfd sp!, {r4 - r10, pc}
+ ldmfd sp!, {r4 - r11, pc}
ENDPROC(cpu_v7_do_suspend)
ENTRY(cpu_v7_do_resume)
--
1.9.1
--
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