From 36b0cb84ee858f02c256d26f0cb4229c78e3399e Mon Sep 17 00:00:00 2001 From: Chunyan Zhang Date: Fri, 1 Dec 2017 03:51:04 +0100 Subject: [PATCH] ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch An additional 'ip' will be pushed to the stack, for restoring the DACR later, if CONFIG_CPU_SW_DOMAIN_PAN defined. However, the fixup still get the err_ptr by add #8*4 to sp, which results in the fact that the code area pointed by the LR will be overwritten, or the kernel will crash if CONFIG_DEBUG_RODATA is enabled. This patch fixes the stack mismatch. Fixes: a5e090acbf54 ("ARM: software-based priviledged-no-access support") Signed-off-by: Lvqiang Huang Signed-off-by: Chunyan Zhang Signed-off-by: Russell King --- arch/arm/lib/csumpartialcopyuser.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S index 1712f132b80d..b83fdc06286a 100644 --- a/arch/arm/lib/csumpartialcopyuser.S +++ b/arch/arm/lib/csumpartialcopyuser.S @@ -85,7 +85,11 @@ .pushsection .text.fixup,"ax" .align 4 9001: mov r4, #-EFAULT +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + ldr r5, [sp, #9*4] @ *err_ptr +#else ldr r5, [sp, #8*4] @ *err_ptr +#endif str r4, [r5] ldmia sp, {r1, r2} @ retrieve dst, len add r2, r2, r1 -- 2.30.2