With just what we need for the STUL_STRARRAY, i.e. the 'struct strarray'
pointer to be used, just like with syscall_arg_fmt->scnprintf() for the
other direction (number -> string).

With this all the strarrays that are associated with syscalls can be
used with '-e syscalls:sys_enter_SYSCALLNAME --filter', and soon will be
possible as well to use with the strace-like shorter form, with just the
syscall names, i.e. something like:

   -e lseek/whence==END/

For now we have to use the longer form:

    # perf trace -e syscalls:sys_enter_lseek
       0.000 pool/2242 syscalls:sys_enter_lseek(fd: 14<anon_inode:[timerfd]>, offset: 0, whence: CUR)
       0.031 pool/2242 syscalls:sys_enter_lseek(fd: 15<anon_inode:[timerfd]>, offset: 0, whence: CUR)
       0.046 pool/2242 syscalls:sys_enter_lseek(fd: 16<anon_inode:[timerfd]>, offset: 0, whence: CUR)
    5003.528 pool/2242 syscalls:sys_enter_lseek(fd: 14<anon_inode:[timerfd]>, offset: 0, whence: CUR)
    5003.575 pool/2242 syscalls:sys_enter_lseek(fd: 15<anon_inode:[timerfd]>, offset: 0, whence: CUR)
    5003.593 pool/2242 syscalls:sys_enter_lseek(fd: 16<anon_inode:[timerfd]>, offset: 0, whence: CUR)
   10002.017 pool/2242 syscalls:sys_enter_lseek(fd: 14<anon_inode:[timerfd]>, offset: 0, whence: CUR)
   10002.051 pool/2242 syscalls:sys_enter_lseek(fd: 15<anon_inode:[timerfd]>, offset: 0, whence: CUR)
   10002.068 pool/2242 syscalls:sys_enter_lseek(fd: 16<anon_inode:[timerfd]>, offset: 0, whence: CUR)
  ^C# perf trace -e syscalls:sys_enter_lseek --filter="whence!=CUR"
       0.000 sshd/24476 syscalls:sys_enter_lseek(fd: 3, offset: 9032, whence: SET)
       0.060 sshd/24476 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libcrypt.so.2.0.0>, offset: 9032, whence: SET)
       0.187 sshd/24476 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libcrypt.so.2.0.0>, offset: 118632, whence: SET)
       0.203 sshd/24476 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libcrypt.so.2.0.0>, offset: 118632, whence: SET)
       0.349 sshd/24476 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libcrypt.so.2.0.0>, offset: 61936, whence: SET)
  ^C#

And for those curious about what are those lseek(DSO, offset, SET), well, its the loader:

  # perf trace -e syscalls:sys_enter_lseek/max-stack=16/ --filter="whence!=CUR"
     0.000 sshd/24495 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libgcrypt.so.20.2.5>, offset: 9032, whence: SET)
                                       __libc_lseek64 (/usr/lib64/ld-2.29.so)
                                       _dl_map_object (/usr/lib64/ld-2.29.so)
     0.067 sshd/24495 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libgcrypt.so.20.2.5>, offset: 9032, whence: SET)
                                       __libc_lseek64 (/usr/lib64/ld-2.29.so)
                                       _dl_map_object_from_fd (/usr/lib64/ld-2.29.so)
                                       _dl_map_object (/usr/lib64/ld-2.29.so)
     0.198 sshd/24495 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libgcrypt.so.20.2.5>, offset: 118632, whence: SET)
                                       __libc_lseek64 (/usr/lib64/ld-2.29.so)
                                       _dl_map_object (/usr/lib64/ld-2.29.so)
     0.219 sshd/24495 syscalls:sys_enter_lseek(fd: 3</usr/lib64/libgcrypt.so.20.2.5>, offset: 118632, whence: SET)
                                       __libc_lseek64 (/usr/lib64/ld-2.29.so)
                                       _dl_map_object_from_fd (/usr/lib64/ld-2.29.so)
                                       _dl_map_object (/usr/lib64/ld-2.29.so)
  ^C#

:-)

With this we can use strings in strarrays in filters, which allows us to
reuse all these that are in place for syscalls:

  $ find tools/perf/trace/beauty/ -name "*.c" | xargs grep -w DEFINE_STRARRAY
  tools/perf/trace/beauty/fcntl.c:	static DEFINE_STRARRAY(fcntl_setlease, "F_");
  tools/perf/trace/beauty/mmap.c:       static DEFINE_STRARRAY(mmap_flags, "MAP_");
  tools/perf/trace/beauty/mmap.c:       static DEFINE_STRARRAY(madvise_advices, "MADV_");
  tools/perf/trace/beauty/sync_file_range.c:       static DEFINE_STRARRAY(sync_file_range_flags, "SYNC_FILE_RANGE_");
  tools/perf/trace/beauty/socket.c:	static DEFINE_STRARRAY(socket_ipproto, "IPPROTO_");
  tools/perf/trace/beauty/mount_flags.c:	static DEFINE_STRARRAY(mount_flags, "MS_");
  tools/perf/trace/beauty/pkey_alloc.c:	static DEFINE_STRARRAY(pkey_alloc_access_rights, "PKEY_");
  tools/perf/trace/beauty/sockaddr.c:DEFINE_STRARRAY(socket_families, "PF_");
  tools/perf/trace/beauty/tracepoints/x86_irq_vectors.c:static DEFINE_STRARRAY(x86_irq_vectors, "_VECTOR");
  tools/perf/trace/beauty/tracepoints/x86_msr.c:static DEFINE_STRARRAY(x86_MSRs, "MSR_");
  tools/perf/trace/beauty/prctl.c:	static DEFINE_STRARRAY(prctl_options, "PR_");
  tools/perf/trace/beauty/prctl.c:	static DEFINE_STRARRAY(prctl_set_mm_options, "PR_SET_MM_");
  tools/perf/trace/beauty/fspick.c:       static DEFINE_STRARRAY(fspick_flags, "FSPICK_");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(ioctl_tty_cmd, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(drm_ioctl_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(sndrv_pcm_ioctl_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(sndrv_ctl_ioctl_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(kvm_ioctl_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(vhost_virtio_ioctl_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(vhost_virtio_ioctl_read_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(perf_ioctl_cmds, "");
  tools/perf/trace/beauty/ioctl.c:	static DEFINE_STRARRAY(usbdevfs_ioctl_cmds, "");
  tools/perf/trace/beauty/fsmount.c:       static DEFINE_STRARRAY(fsmount_attr_flags, "MOUNT_ATTR_");
  tools/perf/trace/beauty/renameat.c:       static DEFINE_STRARRAY(rename_flags, "RENAME_");
  tools/perf/trace/beauty/kcmp.c:	static DEFINE_STRARRAY(kcmp_types, "KCMP_");
  tools/perf/trace/beauty/move_mount.c:       static DEFINE_STRARRAY(move_mount_flags, "MOVE_MOUNT_");
  $

Well, some, as the mmap flags are like:

  $ tools/perf/trace/beauty/mmap_flags.sh
  static const char *mmap_flags[] = {
  	[ilog2(0x40) + 1] = "32BIT",
  	[ilog2(0x01) + 1] = "SHARED",
  	[ilog2(0x02) + 1] = "PRIVATE",
  	[ilog2(0x10) + 1] = "FIXED",
  	[ilog2(0x20) + 1] = "ANONYMOUS",
  	[ilog2(0x008000) + 1] = "POPULATE",
  	[ilog2(0x010000) + 1] = "NONBLOCK",
  	[ilog2(0x020000) + 1] = "STACK",
  	[ilog2(0x040000) + 1] = "HUGETLB",
  	[ilog2(0x080000) + 1] = "SYNC",
  	[ilog2(0x100000) + 1] = "FIXED_NOREPLACE",
  	[ilog2(0x0100) + 1] = "GROWSDOWN",
  	[ilog2(0x0800) + 1] = "DENYWRITE",
  	[ilog2(0x1000) + 1] = "EXECUTABLE",
  	[ilog2(0x2000) + 1] = "LOCKED",
  	[ilog2(0x4000) + 1] = "NORESERVE",
  };
  $

So we'll need a strarray__strtoul_flags() that will break donw the flags
into tokens separated by '|' before doing the lookup and then go on
reconstructing the value from, say:

      # perf trace -e syscalls:sys_enter_mmap --filter="flags==PRIVATE|FIXED|DENYWRITE"

into:

      # perf trace -e syscalls:sys_enter_mmap --filter="flags==0x2|0x10|0x0800"

and finally into:

      # perf trace -e syscalls:sys_enter_mmap --filter="flags==0x812"

That is what we see if we don't use the augmented view obtained from:

  # perf trace -e mmap
  <SNIP>
  211792.885 procmail/15393 mmap(addr: 0x7fcd11645000, len: 8192, prot: READ, flags: PRIVATE|FIXED|DENYWRITE, fd: 8, off: 0xa000) = 0x7fcd11645000
  <SNIP>

But plain use tracefs:

        procmail-15559 [000] .... 54557.178262: sys_mmap(addr: 7f5c9bf7a000, len: 9b000, prot: 1, flags: 812, fd: 3, off: a9000)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@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-c6mgkjt8ujnc263eld5tb7q3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>