openwrt/target/linux/zynq/patches-4.19/110-ARM-zynq-Use-memcpy_toio-instead-of-memcpy.patch

From a801d4aa6000f7ba0ffc5ba9d841af62ec7e0bb1 Mon Sep 17 00:00:00 2001
From: Luis Araneda <luaraneda@gmail.com>
Date: Tue, 30 Jul 2019 00:29:03 -0400
Subject: [RFC PATCH] ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up

This fixes a kernel panic (read overflow) on memcpy when
FORTIFY_SOURCE is enabled.

The computed size of memcpy args are:
- p_size (dst): 4294967295 = (size_t) -1
- q_size (src): 1
- size (len): 8

Additionally, the memory is marked as __iomem, so one of
the memcpy_* functions should be used for read/write

Signed-off-by: Luis Araneda <luaraneda@gmail.com>
---
As of 2019-08-03, this patch is under review and waiting
comments from the maintainer / author
--
 arch/arm/mach-zynq/platsmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c
@@ -65,7 +65,7 @@ int zynq_cpun_start(u32 address, int cpu
 			* 0x4: Jump by mov instruction
 			* 0x8: Jumping address
 			*/
-			memcpy((__force void *)zero, &zynq_secondary_trampoline,
+			memcpy_toio(zero, &zynq_secondary_trampoline,
 							trampoline_size);
 			writel(address, zero + trampoline_size);