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Date: Wed, 3 Apr 2024 11:21:17 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Yang Jihong <yangjihong@bytedance.com>
Cc: peterz@infradead.org, mingo@redhat.com, namhyung@kernel.org,
	mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
	jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com,
	kan.liang@linux.intel.com, james.clark@arm.com,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf beauty: Fix AT_EACCESS undeclared build error for
 system with kernel versions lower than v5.8
Message-ID: <Zg1l3RUMrzJaBYcP@x1>
References: <20240403122558.1438841-1-yangjihong@bytedance.com>
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In-Reply-To: <20240403122558.1438841-1-yangjihong@bytedance.com>

On Wed, Apr 03, 2024 at 08:25:58PM +0800, Yang Jihong wrote:
> In the environment of ubuntu20.04 (the version of kernel headers is 5.4),
> there is an error in building perf:
> 
>     CC      trace/beauty/fs_at_flags.o
>   trace/beauty/fs_at_flags.c: In function ‘faccessat2__scnprintf_flags’:
>   trace/beauty/fs_at_flags.c:35:14: error: ‘AT_EACCESS’ undeclared (first use in this function); did you mean ‘DN_ACCESS’?
>      35 |  if (flags & AT_EACCESS) {
>         |              ^~~~~~~~~~
>         |              DN_ACCESS
>   trace/beauty/fs_at_flags.c:35:14: note: each undeclared identifier is reported only once for each function it appears in
> 
> commit 8a1ad4413519 ("tools headers: Remove now unused copies of
> uapi/{fcntl,openat2}.h and asm/fcntl.h") removes fcntl.h from tools
> headers directory, and fs_at_flags.c uses the 'AT_EACCESS' macro.
> This macro was introduced in the kernel version v5.8.
> For system with a kernel version older than this version,
> it will cause compilation to fail.

Thanks, I test on it, but since I didn't found libtraceevent-devel
available there, then I have to build with NO_LIBTRACEEVENT=1 and thus
this doesn't get built :-\

Thanks, applying.

- Arnaldo
 
> Fixes: 8a1ad4413519 ("tools headers: Remove now unused copies of uapi/{fcntl,openat2}.h and asm/fcntl.h")
> Signed-off-by: Yang Jihong <yangjihong@bytedance.com>
> ---
>  tools/perf/trace/beauty/fs_at_flags.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/tools/perf/trace/beauty/fs_at_flags.c b/tools/perf/trace/beauty/fs_at_flags.c
> index c1365e8f0b96..c200669cb944 100644
> --- a/tools/perf/trace/beauty/fs_at_flags.c
> +++ b/tools/perf/trace/beauty/fs_at_flags.c
> @@ -10,6 +10,14 @@
>  #include <linux/fcntl.h>
>  #include <linux/log2.h>
>  
> +/*
> + * uapi/linux/fcntl.h does not keep a copy in tools headers directory,
> + * for system with kernel versions before v5.8, need to sync AT_EACCESS macro.
> + */
> +#ifndef AT_EACCESS
> +#define AT_EACCESS 0x200
> +#endif
> +
>  #include "trace/beauty/generated/fs_at_flags_array.c"
>  static DEFINE_STRARRAY(fs_at_flags, "AT_");
>  
> -- 
> 2.25.1
>