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Subject[RESEND PATCH] ARM: Fix csum_partial_copy_from_user() stack mismatch
Date
From: Lvqiang Huang <Lvqiang.Huang@spreadtrum.com>

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.

Signed-off-by: Lvqiang Huang <Lvqiang.Huang@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
---
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 1712f13..b83fdc0 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
--
2.7.4
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