Re: [Qemu-devel] Commit 34b9c07a3 (microblaze: Disable stack protection from bootloader) causing qemu crash

[Edgar E. Iglesias]

On Fri, Feb 07, 2014 at 03:17:31PM -0800, Guenter Roeck wrote:
> Michal,
> 
> commit 34b9c07a3 (microblaze: Disable stack protection from bootloader) 
> results
> in the following qemu crash in 3.14-rc1.
> 
> /opt/buildbot/bin/qemu-system-microblaze -M petalogix-s3adsp1800 -kernel 
> arch/microblaze/boot/linux.bin -no-reboot -append "console=ttyUL0,115200 " 
> -nographic
> qemu: fatal: fetching nop sequence
> 
> IN: PC=20
> rmsr=4300 resr=7 rear=c0389fe8 debug=0 imm=ffffffd0 iflags=0 fsr=0
> btaken=1 btarget=c03a9f24 mode=kernel(saved=kernel) eip=512 ie=0
> r00=00000000 r01=c0389fcc r02=c0386a52 r03=000000c0
> r04=00004100 r05=9052fab4 r06=00000000 r07=90530ab4
> r08=00000000 r09=00400000 r10=00400000 r11=c03a9f24
> r12=00621000 r13=40aef0c0 r14=00000000 r15=c0000294
> r16=00000000 r17=c03a9f28 r18=00000000 r19=00000000
> r20=00000000 r21=00000000 r22=00000000 r23=00000000
> r24=00000000 r25=00000000 r26=00000000 r27=00000000
> r28=00000000 r29=00400000 r30=00000300 r31=c03932d4
> 
> 
> Aborted (core dumped)
> 
> I have seen this with qemu 1.6.0 and 1.7.0.
> 
> Reverting the patch solves the problem.
> 
> Is this a qemu bug, a bug in the code, or a bug in my configuration ?
> Any idea what I can do about it ?

Hi Guenter,

Seems to be a typo in the kernel, the following should fix it.

Cheers,
Edgar

---8<---
From: "Edgar E. Iglesias" <address@hidden>
Date: Sat, 8 Feb 2014 10:59:59 +1000
Subject: [PATCH] microblaze: Fix a typo when disabling stack protection

Correct a typo causing the stack protector to be left enabled.
0xFFFFFFF -> 0xFFFFFFFF

Signed-off-by: Edgar E. Iglesias <address@hidden>
---
 arch/microblaze/kernel/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S
index b7fb043..17645b2 100644
--- a/arch/microblaze/kernel/head.S
+++ b/arch/microblaze/kernel/head.S
@@ -66,7 +66,7 @@ real_start:
        mts     rmsr, r0
 /* Disable stack protection from bootloader */
        mts     rslr, r0
-       addi    r8, r0, 0xFFFFFFF
+       addi    r8, r0, 0xFFFFFFFF
        mts     rshr, r8
 /*
  * According to Xilinx, msrclr instruction behaves like 'mfs rX,rpc'
-- 
1.9.rc2