linux-imx

perf trace: Beautify 'fsmount' arguments

Use existing beautifiers for the first arg, fd, assigned using the
heuristic that looks for syscall arg names and associates SCA_FD with
'fd' named argumes, and wire up the recently introduced fsmount
attr_flags table generator.

Now it should be possible to just use:

   perf trace -e fsmount

As root and see all fsmount syscalls with its args beautified.

  # cat sys_fsmount.c
  #define _GNU_SOURCE        /* See feature_test_macros(7) */
  #include <unistd.h>
  #include <sys/syscall.h>   /* For SYS_xxx definitions */

  #define __NR_fsmount 432

  #define MOUNT_ATTR_RDONLY	 0x00000001 /* Mount read-only */
  #define MOUNT_ATTR_NOSUID	 0x00000002 /* Ignore suid and sgid bits */
  #define MOUNT_ATTR_NODEV	 0x00000004 /* Disallow access to device special files */
  #define MOUNT_ATTR_NOEXEC	 0x00000008 /* Disallow program execution */
  #define MOUNT_ATTR__ATIME	 0x00000070 /* Setting on how atime should be updated */
  #define MOUNT_ATTR_RELATIME	 0x00000000 /* - Update atime relative to mtime/ctime. */
  #define MOUNT_ATTR_NOATIME	 0x00000010 /* - Do not update access times. */
  #define MOUNT_ATTR_STRICTATIME 0x00000020 /* - Always perform atime updates */
  #define MOUNT_ATTR_NODIRATIME	 0x00000080 /* Do not update directory access times */

  static inline int sys_fsmount(int fs_fd, int flags, int attr_flags)
  {
  	syscall(__NR_fsmount, fs_fd, flags, attr_flags);
  }

  int main(int argc, char *argv[])
  {
  	int attr_flags = 0, fs_fd = 0;

  	sys_fsmount(fs_fd++, 0, attr_flags);
  	attr_flags |= MOUNT_ATTR_RDONLY;
  	sys_fsmount(fs_fd++, 1, attr_flags);
  	attr_flags |= MOUNT_ATTR_NOSUID;
  	sys_fsmount(fs_fd++, 0, attr_flags);
  	attr_flags |= MOUNT_ATTR_NODEV;
  	sys_fsmount(fs_fd++, 1, attr_flags);
  	attr_flags |= MOUNT_ATTR_NOEXEC;
  	sys_fsmount(fs_fd++, 0, attr_flags);
  	attr_flags |= MOUNT_ATTR_NOATIME;
  	sys_fsmount(fs_fd++, 1, attr_flags);
  	attr_flags |= MOUNT_ATTR_STRICTATIME;
  	sys_fsmount(fs_fd++, 0, attr_flags);
  	attr_flags |= MOUNT_ATTR_NODIRATIME;
  	sys_fsmount(fs_fd++, 0, attr_flags);
  	return 0;
  }
  #
  # perf trace -e fsmount ./sys_fsmount
  fsmount(0, 0, MOUNT_ATTR_RELATIME)      = -1 EINVAL (Invalid argument)
  fsmount(1, FSMOUNT_CLOEXEC, MOUNT_ATTR_RDONLY|MOUNT_ATTR_RELATIME) = -1 EINVAL (Invalid argument)
  fsmount(2, 0, MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_RELATIME) = -1 EINVAL (Invalid argument)
  fsmount(3, FSMOUNT_CLOEXEC, MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_RELATIME) = -1 EBADF (Bad file descriptor)
  fsmount(4, 0, MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_RELATIME) = -1 EBADF (Bad file descriptor)
  fsmount(5, FSMOUNT_CLOEXEC, MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME) = -1 EBADF (Bad file descriptor)
  fsmount(6, 0, MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME|MOUNT_ATTR_STRICTATIME) = -1 EINVAL (Invalid argument)
  fsmount(7, 0, MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME) = -1 EINVAL (Invalid argument)
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-w71uge0sfo6ns9uclhwtthca@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>