linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-30  4:43 Luis Araneda [this message]
2019-07-30 10:47 ` [RFC PATCH] ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up Russell King - ARM Linux admin
2019-07-31  4:12   ` Luis Araneda
2019-08-05  9:53     ` Michal Simek
2019-08-06  1:52       ` Luis Araneda

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190730044326.1805-1-luaraneda@gmail.com \
    --to=luaraneda@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=michal.simek@xilinx.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).