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From: Luis Araneda <luaraneda@gmail.com>
To: linux@armlinux.org.uk, michal.simek@xilinx.com
Cc: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Luis Araneda <luaraneda@gmail.com>
Subject: [RFC PATCH] ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up
Date: Tue, 30 Jul 2019 00:43:26 -0400	[thread overview]
Message-ID: <20190730044326.1805-1-luaraneda@gmail.com> (raw)

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>
---

For anyone trying to reproduce / debug this, it panics
before the console has any output.
I used JTAG to find the panic, but I had to comment-out
the call to "zynq_slcr_cpu_stop" as it stops the JTAG
interface and the connection is dropped, at least with OpenOCD.

I run-tested this on a Digilent Zybo Z7 board
---
 arch/arm/mach-zynq/platsmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
index a7cfe07156f4..407abade7336 100644
--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c
@@ -57,7 +57,7 @@ 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);
 
-- 
2.22.0


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WARNING: multiple messages have this Message-ID (diff)
From: Luis Araneda <luaraneda@gmail.com>
To: linux@armlinux.org.uk, michal.simek@xilinx.com
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Luis Araneda <luaraneda@gmail.com>
Subject: [RFC PATCH] ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up
Date: Tue, 30 Jul 2019 00:43:26 -0400	[thread overview]
Message-ID: <20190730044326.1805-1-luaraneda@gmail.com> (raw)

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>
---

For anyone trying to reproduce / debug this, it panics
before the console has any output.
I used JTAG to find the panic, but I had to comment-out
the call to "zynq_slcr_cpu_stop" as it stops the JTAG
interface and the connection is dropped, at least with OpenOCD.

I run-tested this on a Digilent Zybo Z7 board
---
 arch/arm/mach-zynq/platsmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
index a7cfe07156f4..407abade7336 100644
--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c
@@ -57,7 +57,7 @@ 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);
 
-- 
2.22.0


             reply	other threads:[~2019-07-30  4:44 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-30  4:43 Luis Araneda [this message]
2019-07-30  4:43 ` [RFC PATCH] ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up Luis Araneda
2019-07-30 10:47 ` Russell King - ARM Linux admin
2019-07-30 10:47   ` Russell King - ARM Linux admin
2019-07-31  4:12   ` Luis Araneda
2019-07-31  4:12     ` Luis Araneda
2019-08-05  9:53     ` Michal Simek
2019-08-05  9:53       ` Michal Simek
2019-08-06  1:52       ` Luis Araneda
2019-08-06  1:52         ` Luis Araneda

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