4.4-stable review patch. If anyone has any objections, please let me know.
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From: Chunyan Zhang zhang.lyra@gmail.com
[ Upstream commit 36b0cb84ee858f02c256d26f0cb4229c78e3399e ]
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 Lvqiang.Huang@spreadtrum.com Signed-off-by: Chunyan Zhang zhang.lyra@gmail.com Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm/lib/csumpartialcopyuser.S | 4 ++++ 1 file changed, 4 insertions(+)
--- 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