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Subject: Re: x86/purgatory: undefined symbol __stack_chk_fail
To:     Andreas Smas <andreas@lonelycoder.com>,
        linux-kernel@vger.kernel.org
References: <CAObFT-SqdcM2Xo7P3FqgwTABao5uoWrb+A3bXy9vKt5rBffSwA@mail.gmail.com>
Cc:     X86 ML <x86@kernel.org>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <6c46ae4d-6837-d1a3-dbe0-03a9efcb862f@infradead.org>
Date:   Fri, 27 Sep 2019 17:48:29 -0700
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On 9/3/19 8:50 AM, Andreas Smas wrote:
> Hi,
> 
> For me, kernels built including this commit
> b059f801a937 (x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS)
> 
> results in kexec() failing to load the kernel:
> 
> kexec: Undefined symbol: __stack_chk_fail
> kexec-bzImage64: Loading purgatory failed
> 
> Can be seen:
> 
> $ readelf -a arch/x86/purgatory/purgatory.ro | grep UND
>      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
>     51: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND __stack_chk_fail
> 
> Using: gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
> 
> Adding -ffreestanding or -fno-stack-protector to ccflags-y in
> arch/x86/purgatory/Makefile
> fixes the problem. Not sure which would be preferred.
> 

Hi,
Do you have a kernel .config file that causes this?
I can't seem to reproduce it.

Thanks.
-- 
~Randy