This is a note to let you know that I've just added the patch titled
MIPS: smp-cps: Stop printing EJTAG exceptions to UART
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mips-smp-cps-stop-printing-ejtag-exceptions-to-uart.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6609ccdc852f7bfbfa54300dd5b3cd89eb4ced6f Mon Sep 17 00:00:00 2001
From: Paul Burton <paulburton@xxxxxxxxxx>
Date: Wed, 3 Feb 2016 03:15:35 +0000
Subject: MIPS: smp-cps: Stop printing EJTAG exceptions to UART
From: Paul Burton <paul.burton@xxxxxxxxxx>
commit 6609ccdc852f7bfbfa54300dd5b3cd89eb4ced6f upstream.
When CONFIG_MIPS_CPS_NS16550 is enabled, some register state is dumped
to the UART when an exception is taken via the BEV on secondary cores.
EJTAG exceptions are architecturally expected to be handled by the BEV
even when Status.BEV is 0. This effectively means that if userland
executes an sdbbp instruction on a secondary core then the kernel dumps
register state to the UART even though the exception is perfectly normal
& expected. Prevent this by simply not dumping information to the UART
for EJTAG exceptions.
Fixes: 609cf6f2291a ("MIPS: CPS: Early debug using an ns16550-compatible UART")
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/12341/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/mips/kernel/cps-vec.S | 1 -
1 file changed, 1 deletion(-)
--- a/arch/mips/kernel/cps-vec.S
+++ b/arch/mips/kernel/cps-vec.S
@@ -245,7 +245,6 @@ LEAF(excep_intex)
.org 0x480
LEAF(excep_ejtag)
- DUMP_EXCEP("EJTAG")
PTR_LA k0, ejtag_debug_handler
jr k0
nop
Patches currently in stable-queue which might be from paulburton@xxxxxxxxxx are
queue-4.4/mips-math-emu-fix-bc1-eq-ne-z-emulation.patch
queue-4.4/mips-smp-cps-stop-printing-ejtag-exceptions-to-uart.patch
queue-4.4/mips-fix-bc1-eq-ne-z-return-offset-calculation.patch
queue-4.4/mips-math-emu-fix-m-add-sub-.s-shifts.patch
