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Subject: Re: [PATCH] csky: Fixup calltrace panic
From:   Guo Ren <ren_guo@c-sky.com>
In-Reply-To: <20200517175220.GA48379@roeck-us.net>
Date:   Wed, 20 May 2020 15:50:42 +0800
Cc:     Guo Ren <guoren@linux.alibaba.com>, linux-csky@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Message-Id: <D93AFA5B-3BF1-4E11-B278-22E980C3EE36@c-sky.com>
References: <20200517175220.GA48379@roeck-us.net>
To:     Guenter Roeck <linux@roeck-us.net>,
        =?gb2312?B?9sTPye21?= <xianmiao_qu@c-sky.com>,
        =?gb2312?B?ydDUxrqj?= <yunhai_shang@c-sky.com>
Sender: linux-kernel-owner@vger.kernel.org
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Hi Guenter,

> ?? 2020??5??18?գ?????1:52??Guenter Roeck <linux@roeck-us.net> д????
> 
> Hi,
> 
> On Wed, May 13, 2020 at 03:15:25PM +0800, Guo Ren wrote:
>> The implementation of show_stack will panic with wrong fp:
>> 
>> addr    = *fp++;
>> 
>> because the fp isn't checked properly.
>> 
>> The current implementations of show_stack, wchan and stack_trace
>> haven't been designed properly, so just deprecate them.
>> 
>> This patch is a reference to riscv's way, all codes are modified from
>> arm's. The patch is passed with:
>> 
>> - cat /proc/<pid>/stack
>> - cat /proc/<pid>/wchan
>> - echo c > /proc/sysrq-trigger
>> 
>> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> 
> This patch results in:
> 
> gcc version: csky-linux-gcc (GCC) 9.3.0
> 
> Building csky:defconfig ... failed
> --------------
> Error log:
> csky-linux-gcc: error: unrecognized command line option '-mbacktrace'; did you mean '-fbacktrace'?
> csky-linux-gcc: error: unrecognized command line option '-mbacktrace'; did you mean '-fbacktrace'?
> make[2]: *** [scripts/mod/devicetable-offsets.s] Error 1
> make[2]: *** Waiting for unfinished jobs....
> csky-linux-gcc: error: unrecognized command line option '-mbacktrace'; did you mean '-fbacktrace'?
> make[2]: *** [scripts/mod/empty.o] Error 1
> make[1]: *** [prepare0] Error 2
> make: *** [sub-make] Error 2
> 
> when trying to build csky images with upstream gcc 9.3.0.
> 
> What version of gcc is needed to build csky images ? Also, would it be
> possible to support the upstream version of gcc ?
> 

We tested it with https://github.com/c-sky/gcc (gcc-6.3)

You can fast test with:


 wget -nc https://gitlab.com/c-sky/buildroot/-/jobs/557072746/artifacts/raw/output/images/toolchain_thead_860_compat_next_glibc_br_defconfig_8f1b5cd7d85509fbafea935ec65c48add73bba07.tar.xz

 mkdir -p host
 tar -Jxf toolchain_thead_860_compat_next_glibc_br_defconfig_8f1b5cd7d85509fbafea935ec65c48add73bba07.tar.xz -C host

 cd linux-xxx

 LD_LIBRARY_PATH=../host/lib make ARCH=csky CROSS_COMPILE=../host/bin/csky-linux- Image


We will upstream -mbacktrace to gcc.org

> Thanks,
> Guenter