From 704ef31a007651f8a44a2a27203ab352abfbb0fe Mon Sep 17 00:00:00 2001 From: Anson Huang Date: Mon, 7 Dec 2015 10:09:19 +0100 Subject: [PATCH] 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: Anson Huang Reviewed-by: Nicolas Pitre Cc: # v3.3+ Signed-off-by: Russell King [Backport from mainline to fix boot hangup on arm with UBSAN] Signed-off-by: Seung-Woo Kim Change-Id: I2c0bb7b8e9d4a0489a4e9e08c65ed7b39fea9ee8 --- 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 3d1054f..d9b03ec 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -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) -- 2.7.4