tools headers API: Update faccessat2 affected files

Update the copies of files affected by:

  c8ffd8bcdd28 ("vfs: add faccessat2 syscall")

To address this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/fcntl.h' differs from latest version at 'include/uapi/linux/fcntl.h'
  diff -u tools/include/uapi/linux/fcntl.h include/uapi/linux/fcntl.h
  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
  diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
  Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl'
  diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl

Which results in 'perf trace' gaining support for the 'faccessat2'
syscall, now one can use:

  # perf trace -e faccessat2

And have system wide tracing of this syscall. And this also will include
it;

  # perf trace -e faccess*

Together with the other variants.

How it affects building/usage (on an x86_64 system):

  $ cp /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c /tmp/syscalls_64.c.before
  $
  [root@five ~]# perf trace -e faccessat2
  event syntax error: 'faccessat2'
                       \___ parser error
  Run 'perf list' for a list of valid events

   Usage: perf trace [<options>] [<command>]
      or: perf trace [<options>] -- <command> [<options>]
      or: perf trace record [<options>] [<command>]
      or: perf trace record [<options>] -- <command> [<options>]

      -e, --event <event>   event/syscall selector. use 'perf list' to list available events
  [root@five ~]#
  $ cp arch/x86/entry/syscalls/syscall_64.tbl tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
  $ git diff
  diff --git a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
  index 37b844f839bc..78847b32e137 100644
  --- a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
  +++ b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
  @@ -359,6 +359,7 @@
   435    common  clone3                  sys_clone3
   437    common  openat2                 sys_openat2
   438    common  pidfd_getfd             sys_pidfd_getfd
  +439    common  faccessat2              sys_faccessat2

   #
   # x32-specific system call numbers start at 512 to avoid cache impact
  $

  $ make -C tools/perf O=/tmp/build/perf/ install-bin
  <SNIP>
  CC       /tmp/build/perf/util/syscalltbl.o
  LD       /tmp/build/perf/util/perf-in.o
  LD       /tmp/build/perf/perf-in.o
  LINK     /tmp/build/perf/perf
  <SNIP>
  [root@five ~]# perf trace -e faccessat2
  ^C[root@five ~]#

Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/tools/include/uapi/linux/fcntl.h b/tools/include/uapi/linux/fcntl.h
index ca88b7bce553..2f86b2ad6d7e 100644
--- a/tools/include/uapi/linux/fcntl.h
+++ b/tools/include/uapi/linux/fcntl.h
@@ -84,10 +84,20 @@
 #define DN_ATTRIB	0x00000020	/* File changed attibutes */
 #define DN_MULTISHOT	0x80000000	/* Don't remove notifier */
 
+/*
+ * The constants AT_REMOVEDIR and AT_EACCESS have the same value.  AT_EACCESS is
+ * meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
+ * unlinkat.  The two functions do completely different things and therefore,
+ * the flags can be allowed to overlap.  For example, passing AT_REMOVEDIR to
+ * faccessat would be undefined behavior and thus treating it equivalent to
+ * AT_EACCESS is valid undefined behavior.
+ */
 #define AT_FDCWD		-100    /* Special value used to indicate
                                            openat should use the current
                                            working directory. */
 #define AT_SYMLINK_NOFOLLOW	0x100   /* Do not follow symbolic links.  */
+#define AT_EACCESS		0x200	/* Test access permitted for
+                                           effective IDs, not real IDs.  */
 #define AT_REMOVEDIR		0x200   /* Remove directory instead of
                                            unlinking file.  */
 #define AT_SYMLINK_FOLLOW	0x400   /* Follow symbolic links.  */