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Subject: Re: [RFC v1 2/2] arch: um: turn BTF_TYPEINFO support off
To:     Brendan Higgins <brendanhiggins@google.com>, jdike@addtoit.com,
        richard@nod.at, akpm@linux-foundation.org, changbin.du@intel.com,
        yamada.masahiro@socionext.com, rdunlap@infradead.org,
        keescook@chromium.org, andriy.shevchenko@linux.intel.com
Cc:     linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
        davidgow@google.com, heidifahim@google.com
References: <20200127193549.187419-1-brendanhiggins@google.com>
 <20200127193549.187419-3-brendanhiggins@google.com>
From:   Anton Ivanov <anton.ivanov@cambridgegreys.com>
Message-ID: <b49a0bf2-eaf7-b2b3-a7f2-db0f280d42ff@cambridgegreys.com>
Date:   Tue, 28 Jan 2020 08:12:28 +0000
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On 27/01/2020 19:35, Brendan Higgins wrote:
> Currently CONFIG_DEBUG_INFO_BTF=y doesn't work on UML:
> 
> scripts/link-vmlinux.sh: line 106: 17463 Segmentation fault      LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
> objcopy: --change-section-vma .BTF=0x0000000000000000 never used
> objcopy: --change-section-lma .BTF=0x0000000000000000 never used
> objcopy: error: the input file '.btf.vmlinux.bin' is empty
> Failed to generate BTF for vmlinux
> Try to disable CONFIG_DEBUG_INFO_BTF
> make: *** [Makefile:1078: vmlinux] Error 1
> 
> So turn off ARCH_HAS_BTF_TYPEINFO support off for the UM architecture.
> 
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> ---
>   arch/um/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/um/Kconfig b/arch/um/Kconfig
> index 0917f8443c285..53e13d8b210e0 100644
> --- a/arch/um/Kconfig
> +++ b/arch/um/Kconfig
> @@ -6,6 +6,7 @@ config UML
>   	bool
>   	default y
>   	select ARCH_HAS_KCOV
> +	select ARCH_NO_BTF_TYPEINFO
>   	select ARCH_NO_PREEMPT
>   	select HAVE_ARCH_AUDITSYSCALL
>   	select HAVE_ARCH_SECCOMP_FILTER
> 

Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>

-- 
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/