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Commit fa0708b3 authored by Anson Huang's avatar Anson Huang Committed by Russell King
Browse files

ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted 



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: default avatarAnson Huang <Anson.Huang@freescale.com>
Reviewed-by: default avatarNicolas Pitre <nico@linaro.org>
Cc: <stable@vger.kernel.org> # v3.3+
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent c014953d

arch/arm/mm/proc-v7.S

+2 −2
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ ENDPROC(cpu_v7_dcache_clean_area) 
.equ	cpu_v7_suspend_size, 4 * 9

#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}
@@ -112,7 +112,7 @@ 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, {r5 - r11}

	ldmfd	sp!, {r4 - r10, pc}

	ldmfd	sp!, {r4 - r11, pc}

ENDPROC(cpu_v7_do_suspend)



ENTRY(cpu_v7_do_resume)