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Sender: Ingo Molnar <mingo.kernel.org@gmail.com>
Date:   Mon, 22 Aug 2022 12:37:53 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     Yang Jihong <yangjihong1@huawei.com>
Cc:     bp@suse.de, ndesaulniers@google.com, nathan@kernel.org,
        alexandre.belloni@bootlin.com, acme@kernel.org,
        namhyung@kernel.org, jolsa@kernel.org,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf tools: Fix compile error for x86
Message-ID: <YwNcgdk/p18Cr+uv@gmail.com>
References: <20220822092557.210209-1-yangjihong1@huawei.com>
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* Yang Jihong <yangjihong1@huawei.com> wrote:

> Commit a0a12c3ed057 ("asm goto: eradicate CC_HAS_ASM_GOTO") eradicates
> CC_HAS_ASM_GOTO, perf on x86 call asm_volatile_goto when compiling __GEN_RMWcc.
> However, asm_volatile_goto is not declared, which causes compilation error:
> 
> In file included from /home/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h:7,
>                  from /home/linux/tools/include/asm/atomic.h:6,
>                  from /home/linux/tools/include/linux/atomic.h:5,
>                  from /home/linux/tools/include/linux/refcount.h:41,
>                  from /home/linux/tools/lib/perf/include/internal/cpumap.h:5,
>                  from /home/linux/tools/perf/util/cpumap.h:7,
>                  from /home/linux/tools/perf/util/env.h:7,
>                  from /home/linux/tools/perf/util/header.h:12,
>                  from pmu-events/pmu-events.c:9:
> /home/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h: In function ‘atomic_dec_and_test’:
> /home/linux/tools/include/asm/../../arch/x86/include/asm/rmwcc.h:7:2: error: implicit declaration of function ‘asm_volatile_goto’ [-Werror=implicit-function-declaration]
>   asm_volatile_goto (fullop "; j" cc " %l[cc_label]"  \
>   ^~~~~~~~~~~~~~~~~
> 
> Solution:
> Define asm_volatile_goto in compiler_types.h if not declared.
> 
> Currently, only x86 architecture uses asm_volatile_goto.
> Theoretically, this patch affects only the x86 architecture.
> 
> Fixes: a0a12c3ed057 ("asm goto: eradicate CC_HAS_ASM_GOTO")
> Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
> ---
>  tools/include/linux/compiler_types.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/include/linux/compiler_types.h b/tools/include/linux/compiler_types.h
> index 24ae3054f304..1bdd834bdd57 100644
> --- a/tools/include/linux/compiler_types.h
> +++ b/tools/include/linux/compiler_types.h
> @@ -36,4 +36,8 @@
>  #include <linux/compiler-gcc.h>
>  #endif
>  
> +#ifndef asm_volatile_goto
> +#define asm_volatile_goto(x...) asm goto(x)
> +#endif

Tested-by: Ingo Molnar <mingo@kernel.org>

Thanks,

	Ingo