[PATCH] perf beauty: Fix AT_EACCESS undeclared build error for system with kernel versions lower than v5.8

[Yang Jihong]

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.

Fixes: 8a1ad4413519 ("tools headers: Remove now unused copies of uapi/{fcntl,openat2}.h and asm/fcntl.h")
Signed-off-by: Yang Jihong <yangjihong@xxxxxxxxxxxxx>
---
 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