This one will need some more work, that 'statbuf' pointer requires a
beautifier in 'perf trace'.

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c
     0.000 weechat/3596 stat(filename: /etc/localtime, statbuf: 0x7ffd87d11f60)
     0.186 perf/29818 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_stat/format)
     0.279 perf/29818 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_newstat/for)
     0.670 perf/29818 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/form)
    60.805 DNS Res~er #20/21308 stat(filename: /etc/resolv.conf, statbuf: 0x7ffa733fe4a0)
    60.836 DNS Res~er #20/21308 open(filename: /etc/hosts, flags: CLOEXEC)
    60.931 perf/29818 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_open/format)
   607.070 DNS Res~er #21/29812 stat(filename: /etc/resolv.conf, statbuf: 0x7ffa5e1fe3f0)
   607.098 DNS Res~er #21/29812 open(filename: /etc/hosts, flags: CLOEXEC)
   999.336 weechat/3596 stat(filename: /etc/localtime, statbuf: 0x7ffd87d11f60)
^C#

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-4lhabe7m4uzo76lnqpyfmnvk@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Helping with tons of boilerplate for syscalls that only want to augment
a filename. Now supporting one such syscall is just a matter of
declaring its arguments struct + using:

  augmented_filename_syscall_enter(openat);

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ls7ojdseu8fxw7fvj77ejpao@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Again, just changing tools/perf/examples/bpf/augmented_syscalls.c, that
is starting to have too much boilerplate, some macro will come to the
rescue.

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c
     0.000 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/cache/app-info/yaml, mask: 16789454)
     0.023 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/lib/app-info/xmls, mask: 16789454)
     0.028 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/lib/app-info/yaml, mask: 16789454)
     0.032 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /usr/share/app-info/yaml, mask: 16789454)
     0.039 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /usr/local/share/app-info/xmls, mask: 16789454)
     0.045 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /usr/local/share/app-info/yaml, mask: 16789454)
     0.049 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /home/acme/.local/share/app-info/yaml, mask: 16789454)
     0.056 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: , mask: 16789454)
     0.010 gmain/2245 inotify_add_watch(fd: 7<anon_inode:inotify>, pathname: /home/acme/~, mask: 16789454)
     0.087 perf/20116 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_inotify_add)
     0.436 perf/20116 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/form)
    56.042 gmain/2791 inotify_add_watch(fd: 4<anon_inode:inotify>, pathname: /var/lib/fwupd/remotes.d/lvfs-testing, mask: 16789454)
   113.986 gmain/1721 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/lib/gdm/~, mask: 16789454)
  3777.265 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
  3777.550 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
^C[root@jouet perf]#

Still not combining raw_syscalls:sys_enter + raw_syscalls:sys_exit, to
get it strace-like, but that probably will come very naturally with some
more wiring up...

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ol83juin2cht9vzquynec5hz@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As described in the previous cset, all we had to do was to touch the
augmented_syscalls.c eBPF program, fire up 'perf trace' with that new
eBPF script in system wide mode and wait for 'open' syscalls, in
addition to 'openat' ones to see that it works:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c
       0.000 StreamT~s #200/16150 openat(dfd: CWD, filename: /home/acme/.mozilla/firefox/fqxhj76d.default/prefs.js, flags: CREAT|EXCL|TRUNC|WRONLY, mode: IRUSR|IWUSR)
       0.065 StreamT~s #200/16150 openat(dfd: CWD, filename: /home/acme/.mozilla/firefox/fqxhj76d.default/prefs-1.js, flags: CREAT|EXCL|TRUNC|WRONLY, mode: IRUSR|IWUSR)
       0.435 StreamT~s #200/16150 openat(dfd: CWD, filename: /home/acme/.mozilla/firefox/fqxhj76d.default/prefs-1.js, flags: CREAT|TRUNC|WRONLY, mode: IRUSR|IWUSR)
       1.875 perf/16772 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/form)
    1227.260 gnome-shell/1463 openat(dfd: CWD, filename: /proc/self/stat)
    1227.397 gnome-shell/2125 openat(dfd: CWD, filename: /proc/self/stat)
    7227.619 gnome-shell/1463 openat(dfd: CWD, filename: /proc/self/stat)
    7227.661 gnome-shell/2125 openat(dfd: CWD, filename: /proc/self/stat)
   10018.079 gnome-shell/1463 openat(dfd: CWD, filename: /proc/self/stat)
   10018.514 perf/16772 openat(dfd: CWD, filename: /proc/1237/status)
   10018.568 perf/16772 openat(dfd: CWD, filename: /proc/1237/status)
   10022.409 gnome-shell/2125 openat(dfd: CWD, filename: /proc/self/stat)
   10090.044 NetworkManager/1237 openat(dfd: CWD, filename: /proc/2125/stat)
   10090.351 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   10090.407 perf/16772 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_open/format)
   10091.763 NetworkManager/1237 openat(dfd: CWD, filename: /proc/2125/stat)
   10091.812 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   10092.807 NetworkManager/1237 openat(dfd: CWD, filename: /proc/2125/stat)
   10092.851 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   10094.650 NetworkManager/1237 openat(dfd: CWD, filename: /proc/1463/stat)
   10094.926 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   10096.010 NetworkManager/1237 openat(dfd: CWD, filename: /proc/1463/stat)
   10096.057 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   10097.056 NetworkManager/1237 openat(dfd: CWD, filename: /proc/1463/stat)
   10097.099 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13228.345 gnome-shell/1463 openat(dfd: CWD, filename: /proc/self/stat)
   13232.734 gnome-shell/2125 openat(dfd: CWD, filename: /proc/self/stat)
   15198.956 lighttpd/16748 open(filename: /proc/loadavg, mode: ISGID|IXOTH)
  ^C#

It even catches 'perf' itself looking at the sys_enter_open and
sys_enter_openat tracefs format dictionaries when it first finds them in
the trace... :-)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-upmogc57uatljr6el6u8537l@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This is the final touch in showing how a syscall argument beautifier can
access the augmented args put in place by the
tools/perf/examples/bpf/augmented_syscalls.c eBPF script, right after
the regular raw syscall args, i.e. the up to 6 long integer values in
the syscall interface.

With this we are able to show the 'openat' syscall arg, now with up to
64 bytes, but in time this will be configurable, just like with the
'strace -s strsize' argument, from 'strace''s man page:

  -s strsize  Specify the maximum string size to print (the default is 32).

This actually is the maximum string to _collect_ and store in the ring
buffer, not just print.

Before:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): cat/9658 openat(dfd: CWD, filename: 0x6626eda8, flags: CLOEXEC)
     0.017 ( 0.007 ms): cat/9658 openat(dfd: CWD, filename: 0x6626eda8, flags: CLOEXEC) = 3
     0.049 (         ): cat/9658 openat(dfd: CWD, filename: 0x66476ce0, flags: CLOEXEC)
     0.051 ( 0.007 ms): cat/9658 openat(dfd: CWD, filename: 0x66476ce0, flags: CLOEXEC) = 3
     0.377 (         ): cat/9658 openat(dfd: CWD, filename: 0x1e8f806b)
     0.379 ( 0.005 ms): cat/9658 openat(dfd: CWD, filename: 0x1e8f806b) = 3
  #

After:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): cat/11966 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
     0.006 ( 0.006 ms): cat/11966 openat(dfd: CWD, filename: 0x4bfdcda8, flags: CLOEXEC) = 3
     0.034 (         ): cat/11966 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC)
     0.036 ( 0.008 ms): cat/11966 openat(dfd: CWD, filename: 0x4c1e4ce0, flags: CLOEXEC) = 3
     0.375 (         ): cat/11966 openat(dfd: CWD, filename: /etc/passwd)
     0.377 ( 0.005 ms): cat/11966 openat(dfd: CWD, filename: 0xe87906b) = 3
  #

This cset should show all the aspects of establishing a protocol between
an eBPF syscall arg augmenter program, tools/perf/examples/bpf/augmented_syscalls.c and
a 'perf trace' beautifier, the one associated with all 'char *' point
syscall args with names that can heuristically be associated with
filenames.

Now to wire up 'open' to show a second syscall using this scheme, all we
have to do now is to change tools/perf/examples/bpf/augmented_syscalls.c,
as 'perf trace' will notice that the perf_sample.raw_size is more than
what is expected for a particular syscall payload as defined by its
tracefs format file and will then use the augmented payload in the
'filename' syscall arg beautifier.

The same protocol will be used for structs such as 'struct sockaddr *',
'struct pollfd', etc, with additions for handling arrays.

This will all be done under the hood when 'perf trace' realizes the
system has the necessary components, and also can be done by providing
a precompiled augmented_syscalls.c eBPF ELF object.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-gj9kqb61wo7m3shtpzercbcr@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To get us a bit more like the sys_enter + sys_exit combo:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): openat(dfd: CWD, filename: 0x31b6dda8, flags: CLOEXEC)
     0.009 ( 0.009 ms): cat/3619 openat(dfd: CWD, filename: 0x31b6dda8, flags: CLOEXEC) = 3
     0.051 (         ): openat(dfd: CWD, filename: 0x31d75ce0, flags: CLOEXEC)
     0.054 ( 0.010 ms): cat/3619 openat(dfd: CWD, filename: 0x31d75ce0, flags: CLOEXEC) = 3
     0.539 (         ): openat(dfd: CWD, filename: 0xca71506b)
     0.543 ( 0.115 ms): cat/3619 openat(dfd: CWD, filename: 0xca71506b) = 3
  #

After:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): cat/4919 openat(dfd: CWD, filename: 0xc8358da8, flags: CLOEXEC)
     0.007 ( 0.005 ms): cat/4919 openat(dfd: CWD, filename: 0xc8358da8, flags: CLOEXEC) = 3
     0.032 (         ): cat/4919 openat(dfd: CWD, filename: 0xc8560ce0, flags: CLOEXEC)
     0.033 ( 0.006 ms): cat/4919 openat(dfd: CWD, filename: 0xc8560ce0, flags: CLOEXEC) = 3
     0.301 (         ): cat/4919 openat(dfd: CWD, filename: 0x91fa306b)
     0.304 ( 0.004 ms): cat/4919 openat(dfd: CWD, filename: 0x91fa306b) = 3
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-6w8ytyo5y655a1hsyfpfily6@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Will be used with augmented syscalls, where we haven't transitioned
completely to combining sys_enter_FOO with sys_exit_FOO, so we'll go
as far as having it similar to the end result, strace like, as possible.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-canomaoiybkswwnhj69u9ae4@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Since we copy all the payload for raw_syscalls:sys_enter plus add
expanded pointers, we can use the syscall id to get its name, etc:

  # grep 'field:.* id' /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/format
	field:long id;	offset:8;	size:8;	signed:1;
  #

Before:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): __augmented_syscalls__:dfd: CWD, filename: 0xec9f9da8, flags: CLOEXEC
     0.006 ( 0.006 ms): cat/2395 openat(dfd: CWD, filename: 0xec9f9da8, flags: CLOEXEC) = 3
     0.041 (         ): __augmented_syscalls__:dfd: CWD, filename: 0xecc01ce0, flags: CLOEXEC
     0.042 ( 0.007 ms): cat/2395 openat(dfd: CWD, filename: 0xecc01ce0, flags: CLOEXEC) = 3
     0.376 (         ): __augmented_syscalls__:dfd: CWD, filename: 0xac0a806b
     0.379 ( 0.006 ms): cat/2395 openat(dfd: CWD, filename: 0xac0a806b) = 3
  #

After:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): openat(dfd: CWD, filename: 0x31b6dda8, flags: CLOEXEC)
     0.009 ( 0.009 ms): cat/3619 openat(dfd: CWD, filename: 0x31b6dda8, flags: CLOEXEC) = 3
     0.051 (         ): openat(dfd: CWD, filename: 0x31d75ce0, flags: CLOEXEC)
     0.054 ( 0.010 ms): cat/3619 openat(dfd: CWD, filename: 0x31d75ce0, flags: CLOEXEC) = 3
     0.539 (         ): openat(dfd: CWD, filename: 0xca71506b)
     0.543 ( 0.115 ms): cat/3619 openat(dfd: CWD, filename: 0xca71506b) = 3
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-epz6y9i0eavmerc5ha98t7gn@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When we attach a eBPF object to a tracepoint, if we return 1, then that
tracepoint will be stored in the perf's ring buffer. In the
augmented_syscalls.c case we want to just attach and _override_ the
tracepoint payload with an augmented, extended one.

In this example, tools/perf/examples/bpf/augmented_syscalls.c, we are
attaching to the 'openat' syscall, and adding, after the
syscalls:sys_enter_openat usual payload as defined by
/sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/format, a
snapshot of its sole pointer arg:

  # grep 'field:.*\*' /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/format
	field:const char * filename;	offset:24;	size:8;	signed:0;
  #

For now this is not being considered, the next csets will make use of
it, but as this is overriding the syscall tracepoint enter, we don't
want that event appearing on the ring buffer, just our synthesized one.

Before:

  # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): __augmented_syscalls__:dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC
     0.006 (         ): syscalls:sys_enter_openat:dfd: CWD, filename: , flags: CLOEXEC
     0.007 ( 0.004 ms): cat/24044 openat(dfd: CWD, filename: 0x216dda8, flags: CLOEXEC                  ) = 3
     0.028 (         ): __augmented_syscalls__:dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC
     0.030 (         ): syscalls:sys_enter_openat:dfd: CWD, filename: , flags: CLOEXEC
     0.031 ( 0.006 ms): cat/24044 openat(dfd: CWD, filename: 0x2375ce0, flags: CLOEXEC                  ) = 3
     0.291 (         ): __augmented_syscalls__:dfd: CWD, filename: /etc/passwd
     0.293 (         ): syscalls:sys_enter_openat:dfd: CWD, filename:
     0.294 ( 0.004 ms): cat/24044 openat(dfd: CWD, filename: 0x637db06b                                 ) = 3
  #

After:

  # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): __augmented_syscalls__:dfd: CWD, filename: 0x9c6a1da8, flags: CLOEXEC
     0.005 ( 0.015 ms): cat/27341 openat(dfd: CWD, filename: 0x9c6a1da8, flags: CLOEXEC                 ) = 3
     0.040 (         ): __augmented_syscalls__:dfd: CWD, filename: 0x9c8a9ce0, flags: CLOEXEC
     0.041 ( 0.006 ms): cat/27341 openat(dfd: CWD, filename: 0x9c8a9ce0, flags: CLOEXEC                 ) = 3
     0.294 (         ): __augmented_syscalls__:dfd: CWD, filename: 0x482a706b
     0.296 ( 0.067 ms): cat/27341 openat(dfd: CWD, filename: 0x482a706b                                 ) = 3
  #

Now lets replace that __augmented_syscalls__ name with the syscall name,
using:

  # grep 'field:.*syscall_nr' /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/format
	field:int __syscall_nr;	offset:8;	size:4;	signed:1;
  #

That the synthesized payload has exactly where the syscall enter
tracepoint puts it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-og4r9k87mzp9hv7el046idmd@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If the tracepoint payload is bigger than what a syscall expected from
what is in its format file in tracefs, then that will be used as
augmented args, i.e. the expansion of syscall arg pointers, with things
like a filename, structs, etc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-bsbqx7xi2ot4q9bf570f7tqs@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Starting with binutils 2.28, aarch64 objdump adds comments to the
disassembly output to show the alternative names of a condition code
[1].

It is assumed that commas in objdump comments could occur in other
arches now or in the future, so this fix is arch-independent.

The fix could have been done with arm64 specific jump__parse and
jump__scnprintf functions, but the jump__scnprintf instruction would
have to have its comment character be a literal, since the scnprintf
functions cannot receive a struct arch easily.

This inconvenience also applies to the generic jump__scnprintf, which is
why we add a raw_comment pointer to struct ins_operands, so the __parse
function assigns it to be re-used by its corresponding __scnprintf
function.

Example differences in 'perf annotate --stdio2' output on an aarch64
perf.data file:

BEFORE: → b.cs   ffff200008133d1c <unwind_frame+0x18c>  // b.hs, dffff7ecc47b
AFTER : ↓ b.cs   18c

BEFORE: → b.cc   ffff200008d8d9cc <get_alloc_profile+0x31c>  // b.lo, b.ul, dffff727295b
AFTER : ↓ b.cc   31c

The branch target labels 18c and 31c also now appear in the output:

BEFORE:        add    x26, x29, #0x80
AFTER : 18c:   add    x26, x29, #0x80

BEFORE:        add    x21, x21, #0x8
AFTER : 31c:   add    x21, x21, #0x8

The Fixes: tag below is added so stable branches will get the update; it
doesn't necessarily mean that commit was broken at the time, rather it
didn't withstand the aarch64 objdump update.

Tested no difference in output for sample x86_64, power arch perf.data files.

[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=bb7eff5206e4795ac79c177a80fe9f4630aaf730Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: b13bbeee ("perf annotate: Fix branch instruction with multiple operands")
Link: http://lkml.kernel.org/r/20180827125340.a2f7e291901d17cea05daba4@arm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This makes sure that the SyS symbols are ignored for any powerpc system,
not just the big endian ones.
Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Fixes: fb6d5942 ("perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc")
Link: http://lkml.kernel.org/r/20180828090848.1914-1-sandipan@linux.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Some implementations of libc do not support the 'm' width modifier as
part of the scanf string format specifier. This can cause the parsing to
fail.  Since the parser never checks if the scanf parsing was
successesful, this can result in a crash.

Change the comm string to be allocated as a fixed size instead of
dynamically using 'm' scanf width modifier. This can be safely done
since comm size is limited to 16 bytes by TASK_COMM_LEN within the
kernel.

This change prevents perf from crashing when linked against bionic as
well as reduces the total number of heap allocations and frees invoked
while accomplishing the same task.
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180830021950.15563-1-cphlipot0@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In the write to the output_fd in the error condition of
record_saved_cmdline(), we are writing 8 bytes from a memory location on
the stack that contains a primitive that is only 4 bytes in size.
Change the primitive to 8 bytes in size to match the size of the write
in order to avoid reading unknown memory from the stack.
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180829061954.18871-1-cphlipot0@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We were emitting 4 lines, two of them misleading:

  make: Entering directory '/home/acme/git/perf/tools/perf'
  <SNIP>
    INSTALL  lib
    INSTALL  include/bpf
    INSTALL  lib
    INSTALL  examples/bpf
  <SNIP>
  make: Leaving directory '/home/acme/git/perf/tools/perf'

Make it more compact by showing just two lines:

  make: Entering directory '/home/acme/git/perf/tools/perf'
    INSTALL  bpf-headers
    INSTALL  bpf-examples
  make: Leaving directory '/home/acme/git/perf/tools/perf'

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-0nvkyciqdkrgy829lony5925@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If evsel is NULL, we should return NULL to avoid a NULL pointer
dereference a bit later in the code.
Signed-off-by: Hisao Tanabe <xtanabe@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 03e0a7df ("perf tools: Introduce bpf-output event")
LPU-Reference: 20180824154556.23428-1-xtanabe@gmail.com
Link: https://lkml.kernel.org/n/tip-e5plzjhx6595a5yjaf22jss3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The new syscall table support for arm64 mistakenly used the system's
asm-generic/unistd.h file when processing the
tools/arch/arm64/include/uapi/asm/unistd.h file's include directive:

	#include <asm-generic/unistd.h>

See "Committer notes" section of commit 2b588243 "perf arm64:
Generate system call table from asm/unistd.h" for more details.

This patch removes the committer's temporary workaround, and instructs
the host compiler to search the build tree's include path for the right
copy of the unistd.h file, instead of the one on the system's
/usr/include path.

It thus fixes the committer's test that cross-builds an arm64 perf on an
x86 platform running Ubuntu 14.04.5 LTS with an old toolchain:

$ tools/perf/arch/arm64/entry/syscalls/mksyscalltbl /gcc-linaro-5.4.1-2017.05-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-gcc gcc `pwd`/tools tools/arch/arm64/include/uapi/asm/unistd.h | grep bpf
	[280] = "bpf",
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 2b588243 ("perf arm64: Generate system call table from asm/unistd.h")
Link: http://lkml.kernel.org/r/20180806172800.bbcec3cfcc51e2facc978bf2@arm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We can safely enable the breakpoint back for both the fail and success
paths by checking only the bp->attr.disabled, which either holds the new
'requested' disabled state or the original breakpoint state.

Committer testing:

At the end of the series, the 'perf test' entry introduced as the first
patch now runs to completion without finding the fixed issues:

  # perf test "bp modify"
  62: x86 bp modify                                         : Ok
  #

In verbose mode:

  # perf test -v "bp modify"
  62: x86 bp modify                                         :
  --- start ---
  test child forked, pid 5161
  rip 5950a0, bp_1 0x5950a0
  in bp_1
  rip 5950a0, bp_1 0x5950a0
  in bp_1
  test child finished with 0
  ---- end ----
  x86 bp modify: Ok
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180827091228.2878-6-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently we enable the breakpoint back only if the breakpoint
modification was successful. If it fails we can leave the breakpoint in
disabled state with attr->disabled == 0.

We can safely enable the breakpoint back for both the fail and success
paths by checking the bp->attr.disabled, which either holds the new
'requested' disabled state or the original breakpoint state.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180827091228.2878-5-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Once the breakpoint was succesfully modified, the attr->disabled value
is in bp->attr.disabled. So there's no reason to set it again, removing
that.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180827091228.2878-4-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We need to change the breakpoint even if the attr with new fields has
disabled set to true.

Current code prevents following user code to change the breakpoint
address:

  ptrace(PTRACE_POKEUSER, child, offsetof(struct user, u_debugreg[0]), addr_1)
  ptrace(PTRACE_POKEUSER, child, offsetof(struct user, u_debugreg[0]), addr_2)
  ptrace(PTRACE_POKEUSER, child, offsetof(struct user, u_debugreg[7]), dr7)

The first PTRACE_POKEUSER creates the breakpoint with attr.disabled set
to true:

  ptrace_set_breakpoint_addr(nr = 0)
    struct perf_event *bp = t->ptrace_bps[nr];

    ptrace_register_breakpoint(..., disabled = true)
      ptrace_fill_bp_fields(..., disabled)
      register_user_hw_breakpoint

So the second PTRACE_POKEUSER will be omitted:

  ptrace_set_breakpoint_addr(nr = 0)
    struct perf_event *bp = t->ptrace_bps[nr];
    struct perf_event_attr attr = bp->attr;

    modify_user_hw_breakpoint(bp, &attr)
      if (!attr->disabled)
        modify_user_hw_breakpoint_check
Reported-by: Milind Chabbi <chabbi.milind@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180827091228.2878-3-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Adding to tests that aims on kernel breakpoint modification bugs.

First test creates HW breakpoint, tries to change it and checks it was
properly changed. It aims on kernel issue that prevents HW breakpoint to
be changed via ptrace interface.

The first test forks, the child sets itself as ptrace tracee and waits
in signal for parent to trace it, then it calls bp_1 and quits.

The parent does following steps:

 - creates a new breakpoint (id 0) for bp_2 function
 - changes that breakpoint to bp_1 function
 - waits for the breakpoint to hit and checks
   it has proper rip of bp_1 function

This test aims on an issue in kernel preventing to change disabled
breakpoints

Second test mimics the first one except for few steps
in the parent:
 - creates a new breakpoint (id 0) for bp_1 function
 - changes that breakpoint to bogus (-1) address
 - waits for the breakpoint to hit and checks
   it has proper rip of bp_1 function

This test aims on an issue in kernel disabling enabled
breakpoint after unsuccesful change.

Committer testing:

  # uname -a
  Linux jouet 4.18.0-rc8-00002-g1236568e #12 SMP Tue Aug 7 14:08:26 -03 2018 x86_64 x86_64 x86_64 GNU/Linux
  # perf test -v "bp modify"
  62: x86 bp modify                                         :
  --- start ---
  test child forked, pid 25671
  in bp_1
  tracee exited prematurely 2
  FAILED arch/x86/tests/bp-modify.c:209 modify test 1 failed

  test child finished with -1
  ---- end ----
  x86 bp modify: FAILED!
  #
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180827091228.2878-2-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The patch changes the parsing of:

	callq  *0x8(%rbx)

from:

  0.26 │     → callq  *8

to:

  0.26 │     → callq  *0x8(%rbx)

in this case an address is followed by a register, thus one can't parse
only the address.

Committer testing:

1) run 'perf record sleep 10'
2) before applying the patch, run:

     perf annotate --stdio2 > /tmp/before

3) after applying the patch, run:

     perf annotate --stdio2 > /tmp/after

4) diff /tmp/before /tmp/after:
  --- /tmp/before 2018-08-28 11:16:03.238384143 -0300
  +++ /tmp/after  2018-08-28 11:15:39.335341042 -0300
  @@ -13274,7 +13274,7 @@
                ↓ jle    128
                  hash_value = hash_table->hash_func (key);
                  mov    0x8(%rsp),%rdi
  -  0.91       → callq  *30
  +  0.91       → callq  *0x30(%r12)
                  mov    $0x2,%r8d
                  cmp    $0x2,%eax
                  node_hash = hash_table->hashes[node_index];
  @@ -13848,7 +13848,7 @@
                   mov    %r14,%rdi
                   sub    %rbx,%r13
                   mov    %r13,%rdx
  -              → callq  *38
  +              → callq  *0x38(%r15)
                   cmp    %rax,%r13
     1.91        ↓ je     240
            1b4:   mov    $0xffffffff,%r13d
  @@ -14026,7 +14026,7 @@
                   mov    %rcx,-0x500(%rbp)
                   mov    %r15,%rsi
                   mov    %r14,%rdi
  -              → callq  *38
  +              → callq  *0x38(%rax)
                   mov    -0x500(%rbp),%rcx
                   cmp    %rax,%rcx
                 ↓ jne    9b0
<SNIP tons of other such cases>
Signed-off-by: Martin Liška <mliska@suse.cz>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Kim Phillips <kim.phillips@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/bd1f3932-be2b-85f9-7582-111ee0a43b07@suse.czSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-core-for-mingo-4.19-20180820' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

LLVM/clang/eBPF: (Arnaldo Carvalho de Melo)

 - Allow passing options to llc in addition to to clang.

Hardware tracing: (Jack Henschel)

 - Improve error message for PMU address filters, clarifying availability of
   that feature in hardware having hardware tracing such as Intel PT.

Python interface: (Jiri Olsa)

 - Fix read_on_cpu() interface.

ELF/DWARF libraries: (Jiri Olsa)

 - Fix handling of the combo compressed module file + decompressed associated
   debuginfo file.

Build (Rasmus Villemoes)

 - Disable parallelism for 'make clean', avoiding multiple submakes deleting
   the same files and causing the build to fail on systems such as Yocto.

Kernel ABI copies: (Arnaldo Carvalho de Melo)

 - Update tools's copy of x86's cpufeatures.h.

 - Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'.

Miscellaneous: (Steven Rostedt)

 - Change libtraceevent to SPDX License format.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

To bring in the change made in this cset:

Fixes: a7bea830 ("x86/asm/64: Use 32-bit XOR to zero registers")

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  LD       /tmp/build/perf/bench/perf-in.o
  LD       /tmp/build/perf/perf-in.o
  LINK     /tmp/build/perf/perf

Silencing this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
  diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-sad22dudoz71qr3tsnlqtkia@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To get the changes in the following csets:

  301d328a ("x86/cpufeatures: Add EPT_AD feature bit")
  706d5168 ("x86/speculation: Support Enhanced IBRS on future CPUs")

No tools were affected, copy it to silence this perf tool build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-bvs8wgd5wp4lz9f0xf1iug5r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Jaroslav reported errors from valgrind over perf python script:

  # echo 0 > /sys/devices/system/cpu/cpu4/online
  # valgrind ./test.py
  ==7524== Memcheck, a memory error detector
  ...
  ==7524== Command: ./test.py
  ==7524==
  pid 7526 exited
  ==7524== Invalid read of size 8
  ==7524==    at 0xCC2C2B3: perf_mmap__read_forward (evlist.c:780)
  ==7524==    by 0xCC2A681: pyrf_evlist__read_on_cpu (python.c:959)
  ...
  ==7524==  Address 0x65c4868 is 16 bytes after a block of size 459,36..
  ==7524==    at 0x4C2B955: calloc (vg_replace_malloc.c:711)
  ==7524==    by 0xCC2F484: zalloc (util.h:35)
  ==7524==    by 0xCC2F484: perf_evlist__alloc_mmap (evlist.c:978)
  ...

The reason for this is in the python interface, that allows a script to
pass arbitrary cpu number, which is then used to access struct
perf_evlist::mmap array. That's obviously wrong and works only when if
all cpus are available and fails if some cpu is missing, like in the
example above.

This patch makes pyrf_evlist__read_on_cpu() search the evlist's maps
array for the proper map to access.

It's linear search at the moment. Based on the way how is the
read_on_cpu used, I don't think we need to be fast in here.  But we
could add some hash in the middle to make it fast/er.

We don't allow python interface to set write_backward event attribute,
so it's safe to check only evlist's mmaps.
Reported-by: Jaroslav Škarvada <jskarvad@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817114556.28000-3-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Store the real cpu number in 'struct perf_mmap', which will be used by
python interface that allows user to read a particular memory map for
given cpu.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jaroslav Škarvada <jskarvad@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817114556.28000-2-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Having comp carrying the compression ID, we no longer need return the
extension. Removing it and updating the automated test.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-14-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add implementation of the is_compressed callback for gzip.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-13-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add implementation of the is_compressed callback for lzma.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-12-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add is_compressed callback to the compressions array, that returns 0 if
the file is compressed or != 0 if not.

The new callback is used to recognize the situation when we have a
'compressed' object, like:

  /lib/modules/.../drivers/net/ethernet/intel/igb/igb.ko.xz

but we need to read its debug data from debuginfo files, which might not
be compressed, like:

  /root/.debug/.build-id/d6/...c4b301f/debug

So even for a 'compressed' object we read debug data from a plain
uncompressed object. To keep this transparent, we detect this in
decompress_kmodule() and return the file descriptor to the uncompressed
file.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-11-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We will add a compression check in the following patch and it makes it
easier if the file processing is done in a single place. It also makes
the current code simpler.

The decompress_kmodule function now returns the fd of the uncompressed
file and the file name in the pathname arg, if it's provided.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-10-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Once we parsed out the compression ID, we dont need to iterate all
available compressions and we can call it directly.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-9-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add comp to 'struct dso' to hold the compression index.  It will be used
in the following patches.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-8-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Store a decompression ID in 'struct kmod_path', so it can be later
stored in 'struct dso'.

Switch 'struct kmod_path's 'comp' from 'bool' to 'int' to return the
compressions array index. Add 0 index item into compressions array, so
that the comp usage stays as it was: 0 - no compression, != 0
compression index.

Update the kmod_path tests.

Committer notes:

Use a designated initializer + terminating comma, e.g. { .fmt = NULL, }, to fix
the build in several distros:

  centos:6:       util/dso.c:201: error: missing initializer
  centos:6:       util/dso.c:201: error: (near initialization for 'compressions[0].decompress')
  debian:9:       util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  fedora:25:      util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  fedora:26:      util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  fedora:27:      util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  oraclelinux:6:  util/dso.c:201: error: missing initializer
  oraclelinux:6:  util/dso.c:201: error: (near initialization for 'compressions[0].decompress')
  ubuntu:12.04.5: util/dso.c:201:2: error: missing initializer [-Werror=missing-field-initializers]
  ubuntu:12.04.5: util/dso.c:201:2: error: (near initialization for 'compressions[0].decompress') [-Werror=missing-field-initializers]
  ubuntu:16.04:   util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  ubuntu:16.10:   util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  ubuntu:16.10:   util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
  ubuntu:17.10:   util/dso.c:201:24: error: missing field 'decompress' initializer [-Werror,-Wmissing-field-initializers]
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-7-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

There's no outside user of it.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-6-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

There's no outside user of it.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-5-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

There's no need to call dso__needs_decompress() twice in the function.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-4-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

There's no need to call dso__needs_decompress() twice in the function.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-3-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>