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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-H6vv8=tax30iYR3zYJ5xun9CmQDAEqdJV4js0m1JbvsKA@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: <a5f383dd-a8d9-114a-3172-f4ef7539a106@loongson.cn>
Date:   Thu, 7 Dec 2023 15:08:48 +0800
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On 12/02/2023 09:45 PM, Huacai Chen wrote:
> Hi, Tiezhu,
>
> 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/kernel/lbt.S b/arch/loongarch/kernel/lbt.S
>> index 9c75120a26d8..4d6914f84c7e 100644
>> --- a/arch/loongarch/kernel/lbt.S
>> +++ b/arch/loongarch/kernel/lbt.S
>> @@ -11,6 +11,7 @@
>>  #include <asm/asm-offsets.h>
>>  #include <asm/errno.h>
>>  #include <asm/regdef.h>
>> +#include <asm/unwind_hints.h>
>>
>>  #define SCR_REG_WIDTH 8
>>
>> @@ -153,3 +154,7 @@ SYM_FUNC_END(_restore_ftop_context)
>>  .L_lbt_fault:
>>         li.w            a0, -EFAULT             # failure
>>         jr              ra
>> +
>> +#ifdef CONFIG_CPU_HAS_LBT
>> +STACK_FRAME_NON_STANDARD _restore_ftop_context
>> +#endif
> This file is only compiled if CONFIG_CPU_HAS_LBT is set, so #ifdef can
> be removed.

OK, will remove it in the next version.

Thanks,
Tiezhu