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Date: Wed, 3 Apr 2024 12:33:24 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: Yang Jihong <yangjihong@bytedance.com>, peterz@infradead.org,
	mingo@redhat.com, namhyung@kernel.org, mark.rutland@arm.com,
	alexander.shishkin@linux.intel.com, jolsa@kernel.org,
	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: <Zg12xH_x_D3yq5ug@x1>
References: <20240403122558.1438841-1-yangjihong@bytedance.com>
 <Zg1l3RUMrzJaBYcP@x1>
 <CAP-5=fW36AauhRemyNah_a4bnLWisV2kxmVZadtSb2xHA8RfrA@mail.gmail.com>
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On Wed, Apr 03, 2024 at 08:05:32AM -0700, Ian Rogers wrote:
> On Wed, Apr 3, 2024 at 7:21 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> >
> > 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.
> 
> Yang also wrote:
> https://lore.kernel.org/lkml/20240314063000.2139877-1-yangjihong@bytedance.com/
> that may have helped you with this.

Yeah, if I change my build container on distros that don't provide
libtraceevent-devel to build it from sources, and then point the perf
build to that directory, I'll try to do that.

And I just merged that patch, thanks for pointing it out.

- Arnaldo
 
> Thanks,
> Ian
> 
> > - 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
> > >