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Subject: Re: [PATCH v5 8/8] LoongArch: Add ORC stack unwinder support
To:     Huacai Chen <chenhuacai@kernel.org>
References: <20231129130701.27744-1-yangtiezhu@loongson.cn>
 <20231129130701.27744-9-yangtiezhu@loongson.cn>
 <CAAhV-H4XBG8XafSvY11j4GW8RGJ_uW=sXc4K0PEcMwyGyUPw=Q@mail.gmail.com>
Cc:     Josh Poimboeuf <jpoimboe@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        loongarch@lists.linux.dev, linux-kernel@vger.kernel.org
From:   Tiezhu Yang <yangtiezhu@loongson.cn>
Message-ID: <eab54e21-550d-12a8-cec1-1634c9c7de20@loongson.cn>
Date:   Thu, 7 Dec 2023 15:23:17 +0800
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On 12/03/2023 08:42 PM, Huacai Chen wrote:
> On Wed, Nov 29, 2023 at 9:07 PM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>>
>> The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
>> similar in concept to a DWARF unwinder. The difference is that the format
>> of the ORC data is much simpler than DWARF, which in turn allows the ORC
>> unwinder to be much simpler and faster.

...

>> diff --git a/arch/loongarch/lib/Makefile b/arch/loongarch/lib/Makefile
>> index a77bf160bfc4..e3023d9a508c 100644
>> --- a/arch/loongarch/lib/Makefile
>> +++ b/arch/loongarch/lib/Makefile
>> @@ -3,6 +3,8 @@
>>  # Makefile for LoongArch-specific library files.
>>  #
>>
>> +OBJECT_FILES_NON_STANDARD := y
>> +
>>  lib-y  += delay.o memset.o memcpy.o memmove.o \
>>            clear_user.o copy_user.o csum.o dump_tlb.o unaligned.o
>>
> I have a draft live-patch patch here:
> https://github.com/chenhuacai/linux/commit/744942cbf456b320f2333638e4bd27d35900284c
>
> But we get such an error:
>
> # selftests: livepatch: test-ftrace.sh
>
>                                       [48/1865]
> [14936.262721] livepatch: failed to register ftrace handler for
> function 'cmdline_proc_show' (-16)
> # TEST: livepatch interaction with ftrace_enabled sysctl ...

...

> I think it is probably because we skip mem* functions here.

I did not test livepatch which is a separate new feature,
let me try it, maybe it needs some time because I am very
busy with some other stuffs.

Thanks,
Tiezhu