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Author SHA1 Message Date
Arnaldo Carvalho de Melo
d5a7e6613b perf trace augmented_syscalls: Augment connect's 'sockaddr' arg 
As the first example of augmenting something other than a 'filename',
augment the 'struct sockaddr' argument for the 'connect' syscall:

  # perf trace -e tools/perf/examples/bpf/augmented_syscalls.c ssh -6 fedorapeople.org
     0.000 ssh/29669 connect(fd: 3, uservaddr: { .family: LOCAL, path: /var/run/nscd/socket }, addrlen: 110)
     0.042 ssh/29669 connect(fd: 3, uservaddr: { .family: LOCAL, path: /var/run/nscd/socket }, addrlen: 110)
     1.329 ssh/29669 connect(fd: 3, uservaddr: { .family: LOCAL, path: /var/run/nscd/socket }, addrlen: 110)
     1.362 ssh/29669 connect(fd: 3, uservaddr: { .family: LOCAL, path: /var/run/nscd/socket }, addrlen: 110)
     1.458 ssh/29669 connect(fd: 3, uservaddr: { .family: LOCAL, path: /var/run/nscd/socket }, addrlen: 110)
     1.478 ssh/29669 connect(fd: 3, uservaddr: { .family: LOCAL, path: /var/run/nscd/socket }, addrlen: 110)
     1.683 ssh/29669 connect(fd: 3<socket:[125942]>, uservaddr: { .family: INET, port: 53, addr: 192.168.43.1 }, addrlen: 16)
     4.710 ssh/29669 connect(fd: 3<socket:[125942]>, uservaddr: { .family: INET6, port: 22, addr: 2610:28:3090:3001:5054:ff:fea7:9474 }, addrlen: 28)
  root@fedorapeople.org: Permission denied (publickey).
  #

This is still just augmenting the syscalls:sys_enter_connect part, later
we'll wire this up to augment the enter+exit combo, like in the
tradicional 'perf trace' and 'strace' outputs.

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-s7l541cbiqb22ifio6z7dpf6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:20 -03:00
Arnaldo Carvalho de Melo
9ab5aadebe perf trace: Add a etcsnoop.c augmented syscalls eBPF utility 
We need to put common stuff into a separate header in tools/perf/include/bpf/
for these augmented syscalls, but I couldn't resist adding a etcsnoop.c tool,
combining augmented syscalls + filtering, that in the future will be passed
from 'perf trace''s command line, to use in building the eBPF program to do
that specific filtering at the source, inside the kernel:

  Running system wide: (hope there isn't any embarassing stuff here...  ;-) )

  # perf trace -e tools/perf/examples/bpf/etcsnoop.c
       0.000 sed/21878 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
    1741.473 cat/21883 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
    1741.892 cat/21883 openat(dfd: CWD, filename: /etc/passwd)
    1748.948 sed/21886 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
    1777.136 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1777.738 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.158 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.528 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.595 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.901 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.939 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.966 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1778.992 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.019 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.045 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.071 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.095 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.121 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.148 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.175 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.202 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.229 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.254 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.279 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.309 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.336 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.363 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.388 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.414 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.442 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.470 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.500 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.529 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.557 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.586 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.617 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.648 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.679 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.706 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.739 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.769 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.798 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.823 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.844 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.862 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.880 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.911 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.942 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1779.972 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1780.004 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
    1780.035 gvfs-udisks2-v/2302 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
   13059.154 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13060.739 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13061.990 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13063.177 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13064.265 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13065.483 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13067.383 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13068.902 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13069.922 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13070.915 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13072.612 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13074.816 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13077.343 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13078.731 NetworkManager/1237 open(filename: /etc/passwd, flags: CLOEXEC)
   13559.064 DNS Res~er #22/21054 open(filename: /etc/hosts, flags: CLOEXEC)
   22419.522 sed/21896 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   24473.313 git/21900 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   24491.988 less/21901 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   24493.793 git/21901 openat(dfd: CWD, filename: /etc/sysless)
   24565.772 sed/21924 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   25878.752 git/21928 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   26075.666 git/21928 open(filename: /etc/localtime, flags: CLOEXEC)
   26075.565 less/21929 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   26076.060 less/21929 openat(dfd: CWD, filename: /etc/sysless)
   26346.395 sed/21932 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   26483.583 sed/21938 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   26954.890 sed/21944 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   27016.165 gsd-color/1762 openat(dfd: CWD, filename: /etc/localtime)
   27016.414 gsd-color/1762 openat(dfd: CWD, filename: /etc/localtime)
   27712.313 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
   27712.616 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
   27829.035 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   27829.368 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   27829.584 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   27829.800 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   27830.107 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   27830.521 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   27961.516 git/21948 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   27987.568 less/21949 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   27988.948 bash/21949 openat(dfd: CWD, filename: /etc/sysless)
   28043.536 sed/21972 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   28736.008 sed/21978 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   34882.664 git/21991 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   34882.664 sort/21990 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   34884.441 uniq/21992 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   35593.098 git/21997 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   35638.839 git/21997 openat(dfd: CWD, filename: /etc/gitattributes)
   35702.851 sed/22000 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   36076.039 sed/22006 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   37569.049 git/22014 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   37673.712 git/22014 open(filename: /etc/localtime, flags: CLOEXEC)
   37781.710 vim/22040 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   37783.667 git/22040 openat(dfd: CWD, filename: /etc/vimrc)
   37792.394 git/22040 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   37792.436 git/22040 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   37792.580 git/22040 open(filename: /etc/passwd, flags: CLOEXEC)
   43893.625 DNS Res~er #23/21365 open(filename: /etc/hosts, flags: CLOEXEC)
   48060.409 nm-dhcp-helper/22044 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48071.745 systemd/1 openat(dfd: CWD, filename: /etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service, flags: CLOEXEC|NOFOLLOW|NOCTTY)
   48082.780 nm-dispatcher/22049 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48111.418 systemd/22049 open(filename: /etc/NetworkManager/dispatcher.d, flags: CLOEXEC|DIRECTORY|NONBLOCK)
   48111.904 systemd/22049 open(filename: /etc/localtime, flags: CLOEXEC)
   48118.357 00-netreport/22052 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48119.668 systemd/22052 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   48119.762 systemd/22052 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48119.887 systemd/22052 open(filename: /etc/passwd, flags: CLOEXEC)
   48120.025 systemd/22052 openat(dfd: CWD, filename: /etc/NetworkManager/dispatcher.d/00-netreport)
   48124.144 hostname/22054 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48125.492 systemd/22052 openat(dfd: CWD, filename: /etc/init.d/functions)
   48127.253 systemd/22052 openat(dfd: CWD, filename: /etc/profile.d/lang.sh)
   48127.388 systemd/22052 openat(dfd: CWD, filename: /etc/locale.conf)
   48137.749 cat/22056 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48143.519 04-iscsi/22058 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48144.438 04-iscsi/22058 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   48144.478 04-iscsi/22058 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48144.577 04-iscsi/22058 open(filename: /etc/passwd, flags: CLOEXEC)
   48144.819 04-iscsi/22058 openat(dfd: CWD, filename: /etc/NetworkManager/dispatcher.d/04-iscsi)
   48145.620 10-ifcfg-rh-ro/22059 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48146.169 systemd/22059 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   48146.207 systemd/22059 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48146.287 systemd/22059 open(filename: /etc/passwd, flags: CLOEXEC)
   48146.387 systemd/22059 openat(dfd: CWD, filename: /etc/NetworkManager/dispatcher.d/10-ifcfg-rh-routes.sh)
   48147.215 11-dhclient/22060 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48147.787 11-dhclient/22060 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   48147.813 11-dhclient/22060 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48147.929 11-dhclient/22060 open(filename: /etc/passwd, flags: CLOEXEC)
   48148.016 11-dhclient/22060 openat(dfd: CWD, filename: /etc/NetworkManager/dispatcher.d/11-dhclient)
   48148.906 grep/22063 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48151.165 11-dhclient/22060 openat(dfd: CWD, filename: /etc/sysconfig/network)
   48151.560 11-dhclient/22060 open(filename: /etc/dhcp/dhclient.d/, flags: CLOEXEC|DIRECTORY|NONBLOCK)
   48151.704 11-dhclient/22060 openat(dfd: CWD, filename: /etc/dhcp/dhclient.d/chrony.sh)
   48153.593 20-chrony/22065 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48154.695 20-chrony/22065 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   48154.756 20-chrony/22065 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48154.914 20-chrony/22065 open(filename: /etc/passwd, flags: CLOEXEC)
   48155.067 20-chrony/22065 openat(dfd: CWD, filename: /etc/NetworkManager/dispatcher.d/20-chrony)
   48156.962 25-polipo/22066 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48157.824 systemd/22066 open(filename: /etc/nsswitch.conf, flags: CLOEXEC)
   48157.866 systemd/22066 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
   48157.981 systemd/22066 open(filename: /etc/passwd, flags: CLOEXEC)
   48158.090 systemd/22066 openat(dfd: CWD, filename: /etc/NetworkManager/dispatcher.d/25-polipo)
   48533.616 gsd-housekeepi/2412 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC)
   87122.021 gsd-color/1762 openat(dfd: CWD, filename: /etc/localtime)
   87122.146 gsd-color/1762 openat(dfd: CWD, filename: /etc/localtime)
   87825.582 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
   87825.844 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
   87829.524 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   87830.531 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   87831.288 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   87832.011 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   87832.672 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   87833.276 gnome-shell/2125 openat(dfd: CWD, filename: /etc/localtime)
   ^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-0o770jvdcy04ee6vhv6v471m@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
16cc63593f perf trace: Augment 'newstat' (aka 'stat') filename ptr 
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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
f6618ce6c0 perf trace: Introduce augmented_filename_syscall_enter() declarator 
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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
9779fc0214 perf trace: Augment inotify_add_watch pathname syscall arg 
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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
daa1284af3 perf trace: Augment the 'open' syscall 'filename' arg 
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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
75d1e30681 perf trace: Use the augmented filename, expanding syscall enter pointers 
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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
6ccc18a9a1 perf trace: Make the augmented_syscalls filter out the tracepoint event 
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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-30 15:52:19 -03:00
Arnaldo Carvalho de Melo
e0b6d2ef32 perf trace: Handle "bpf-output" events associated with "__augmented_syscalls__" BPF map 
Add an example BPF script that writes syscalls:sys_enter_openat raw
tracepoint payloads augmented with the first 64 bytes of the "filename"
syscall pointer arg.

Then catch it and print it just like with things written to the
"__bpf_stdout__" map associated with a PERF_COUNT_SW_BPF_OUTPUT software
event, by just letting the default tracepoint handler in 'perf trace',
trace__event_handler(), to use bpf_output__fprintf(trace, sample), just
like it does with all other PERF_COUNT_SW_BPF_OUTPUT events, i.e. just
do a dump on the payload, so that we can check if what is being printed
has at least the first 64 bytes of the "filename" arg:

The augmented_syscalls.c eBPF script:

  # cat tools/perf/examples/bpf/augmented_syscalls.c
  // SPDX-License-Identifier: GPL-2.0

  #include <stdio.h>

  struct bpf_map SEC("maps") __augmented_syscalls__ = {
       .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
       .key_size = sizeof(int),
       .value_size = sizeof(u32),
       .max_entries = __NR_CPUS__,
  };

  struct syscall_enter_openat_args {
	unsigned long long common_tp_fields;
	long		   syscall_nr;
	long		   dfd;
	char		   *filename_ptr;
	long		   flags;
	long		   mode;
  };

  struct augmented_enter_openat_args {
	struct syscall_enter_openat_args args;
	char				 filename[64];
  };

  int syscall_enter(openat)(struct syscall_enter_openat_args *args)
  {
	struct augmented_enter_openat_args augmented_args;

	probe_read(&augmented_args.args, sizeof(augmented_args.args), args);
	probe_read_str(&augmented_args.filename, sizeof(augmented_args.filename), args->filename_ptr);
	perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU,
			  &augmented_args, sizeof(augmented_args));
	return 1;
  }

  license(GPL);
  #

So it will just prepare a raw_syscalls:sys_enter payload for the
"openat" syscall.

This will eventually be done for all syscalls with pointer args,
globally or just when the user asks, using some spec, which args of
which syscalls it wants "expanded" this way, we'll probably start with
just all the syscalls that have char * pointers with familiar names, the
ones we already handle with the probe:vfs_getname kprobe if it is in
place hooking the kernel getname_flags() function used to copy from user
the paths.

Running it we get:

  # perf trace -e perf/tools/perf/examples/bpf/augmented_syscalls.c,openat cat /etc/passwd > /dev/null
     0.000 (         ): __augmented_syscalls__:X?.C......................`\..................../etc/ld.so.cache..#......,....ao.k...............k......1.".........
     0.006 (         ): syscalls:sys_enter_openat:dfd: CWD, filename: 0x5c600da8, flags: CLOEXEC
     0.008 ( 0.005 ms): cat/31292 openat(dfd: CWD, filename: 0x5c600da8, flags: CLOEXEC                 ) = 3
     0.036 (         ): __augmented_syscalls__:X?.C.......................\..................../lib64/libc.so.6......... .\....#........?.......=.C..../.".........
     0.037 (         ): syscalls:sys_enter_openat:dfd: CWD, filename: 0x5c808ce0, flags: CLOEXEC
     0.039 ( 0.007 ms): cat/31292 openat(dfd: CWD, filename: 0x5c808ce0, flags: CLOEXEC                 ) = 3
     0.323 (         ): __augmented_syscalls__:X?.C.....................P....................../etc/passwd......>.C....@................>.C.....,....ao.>.C........
     0.325 (         ): syscalls:sys_enter_openat:dfd: CWD, filename: 0xe8be50d6
     0.327 ( 0.004 ms): cat/31292 openat(dfd: CWD, filename: 0xe8be50d6                                 ) = 3
  #

We need to go on optimizing this to avoid seding trash or zeroes in the
pointer content payload, using the return from bpf_probe_read_str(), but
to keep things simple at this stage and make incremental progress, lets
leave it at that for now.

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-g360n1zbj6bkbk6q0qo11c28@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-08 15:55:57 -03:00
Arnaldo Carvalho de Melo
53a5d7b800 perf bpf: Add bpf/stdio.h wrapper to bpf_perf_event_output function 
That, together with the map __bpf_output__ that is already handled by
'perf trace' to print that event's contents as strings provides a
debugging facility, to show it in use, print a simple string everytime
the syscalls:sys_enter_openat() syscall tracepoint is hit:

  # cat tools/perf/examples/bpf/hello.c
  #include <stdio.h>

  int syscall_enter(openat)(void *args)
  {
	  puts("Hello, world\n");
	  return 0;
  }

  license(GPL);
  #
  # perf trace -e openat,tools/perf/examples/bpf/hello.c cat /etc/passwd > /dev/null
     0.016 (         ): __bpf_stdout__:Hello, world
     0.018 ( 0.010 ms): cat/9079 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC) = 3
     0.057 (         ): __bpf_stdout__:Hello, world
     0.059 ( 0.011 ms): cat/9079 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC) = 3
     0.417 (         ): __bpf_stdout__:Hello, world
     0.419 ( 0.009 ms): cat/9079 openat(dfd: CWD, filename: /etc/passwd) = 3
  #

This is part of an ongoing experimentation on making eBPF scripts as
consumed by perf to be as concise as possible and using familiar
concepts such as stdio.h functions, that end up just wrapping the
existing BPF functions, trying to hide as much boilerplate as possible
while using just conventions and C preprocessor tricks.

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-4tiaqlx5crf0fwpe7a6j84x7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-08 15:55:55 -03:00
Arnaldo Carvalho de Melo
dda9ac966d perf bpf: Add 'syscall_enter' probe helper for syscall enter tracepoints 
Allowing one to hook into the syscalls:sys_enter_NAME tracepoints,
an example is provided that hooks into the 'openat' syscall.

Using it with the probe:vfs_getname probe into getname_flags to get the
filename args as it is copied from userspace:

  # perf probe -l
  probe:vfs_getname    (on getname_flags:73@acme/git/linux/fs/namei.c with pathname)
  # perf trace -e probe:*getname,tools/perf/examples/bpf/sys_enter_openat.c cat /etc/passwd > /dev/null
     0.000 probe:vfs_getname:(ffffffffbd2a8983) pathname="/etc/ld.so.preload"
     0.022 syscalls:sys_enter_openat:dfd: CWD, filename: 0xafbe8da8, flags: CLOEXEC
     0.027 probe:vfs_getname:(ffffffffbd2a8983) pathname="/etc/ld.so.cache"
     0.054 syscalls:sys_enter_openat:dfd: CWD, filename: 0xafdf0ce0, flags: CLOEXEC
     0.057 probe:vfs_getname:(ffffffffbd2a8983) pathname="/lib64/libc.so.6"
     0.316 probe:vfs_getname:(ffffffffbd2a8983) pathname="/usr/lib/locale/locale-archive"
     0.375 syscalls:sys_enter_openat:dfd: CWD, filename: 0xe2b2b0b4
     0.379 probe:vfs_getname:(ffffffffbd2a8983) pathname="/etc/passwd"
  #

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-2po9jcqv1qgj0koxlg8kkg30@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-08-08 15:55:44 -03:00
Arnaldo Carvalho de Melo
d8fc764d0b perf bpf: Add probe() helper to reduce kprobes boilerplate 
So that kprobe definitions become:

  int probe(function, variables)(void *ctx, int err, var1, var2, ...)

The existing 5sec.c, got converted and goes from:

  SEC("func=hrtimer_nanosleep rqtp->tv_sec")
  int func(void *ctx, int err, long sec)
  {
  }

To:

  int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec)
  {
  }

If we decide to add tv_nsec as well, then it becomes:

  $ cat tools/perf/examples/bpf/5sec.c
  #include <bpf.h>

  int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec)
  {
	  return sec == 5;
  }

  license(GPL);
  $

And if we run it, system wide as before and run some 'sleep' with values
for the tv_nsec field, we get:

  # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c
     0.000 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=100000000
  9641.650 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=123450001
  ^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-1v9r8f6ds5av0w9pcwpeknyl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-05-15 14:31:24 -03:00
Arnaldo Carvalho de Melo
1f477305ab perf bpf: Add license(NAME) helper 
To further reduce boilerplate.

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-vst6hj335s0ebxzqltes3nsc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-05-15 14:31:24 -03:00
Arnaldo Carvalho de Melo
7542b767b0 perf bpf: Add kprobe example to catch 5s naps 
Description:

. Disable strace like syscall tracing (--no-syscalls), or try tracing
  just some (-e *sleep).

. Attach a filter function to a kernel function, returning when it should
  be considered, i.e. appear on the output:

  $ cat tools/perf/examples/bpf/5sec.c
  #include <bpf.h>

  SEC("func=hrtimer_nanosleep rqtp->tv_sec")
  int func(void *ctx, int err, long sec)
  {
	  return sec == 5;
  }

  char _license[] SEC("license") = "GPL";
  int _version SEC("version") = LINUX_VERSION_CODE;
  $

. Run it system wide, so that any sleep of >= 5 seconds and < than 6
  seconds gets caught.

. Ask for callgraphs using DWARF info, so that userspace can be unwound

. While this is running, run something like "sleep 5s".

  # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/
     0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5
                                       hrtimer_nanosleep ([kernel.kallsyms])
                                       __x64_sys_nanosleep ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       entry_SYSCALL_64 ([kernel.kallsyms])
                                       __GI___nanosleep (/usr/lib64/libc-2.26.so)
                                       rpl_nanosleep (/usr/bin/sleep)
                                       xnanosleep (/usr/bin/sleep)
                                       main (/usr/bin/sleep)
                                       __libc_start_main (/usr/lib64/libc-2.26.so)
                                       _start (/usr/bin/sleep)
  ^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-2nmxth2l2h09f9gy85lyexcq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-05-15 14:31:24 -03:00
Arnaldo Carvalho de Melo
dd8e4ead6e perf bpf: Add bpf.h to be used in eBPF proggies 
So, the first helper is the one shortening a variable/function section
attribute, from, for instance:

  char _license[] __attribute__((section("license"), used)) = "GPL";

to:

  char _license[] SEC("license") = "GPL";

Convert empty.c to that and it becomes:

  # cat ~acme/lib/examples/perf/bpf/empty.c
  #include <bpf.h>

  char _license[] SEC("license") = "GPL";
  int _version SEC("version") = LINUX_VERSION_CODE;
  #

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-zmeg52dlvy51rdlhyumfl5yf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-05-15 14:31:23 -03:00
Arnaldo Carvalho de Melo
8f12a2ff00 perf bpf: Add 'examples' directories 
The first one is the bare minimum that bpf infrastructure accepts before
it expects actual events to be set up:

  $ cat tools/perf/examples/bpf/empty.c
  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
  $

If you remove that "version" line, then it will be refused with:

  # perf trace -e tools/perf/examples/bpf/empty.c
  event syntax error: 'tools/perf/examples/bpf/empty.c'
                       \___ Failed to load tools/perf/examples/bpf/empty.c from source: 'version' section incorrect or lost

  (add -v to see detail)
  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
  #

The next ones will, step by step, show simple filters, then the needs
for headers will be made clear, it will be put in place and tested with
new examples, rinse, repeat.

Back to using this first one to test the perf+bpf infrastructure:

If we run it will fail, as no functions are present connecting with,
say, a tracepoint or a function using the kprobes or uprobes
infrastructure:

  # perf trace -e tools/perf/examples/bpf/empty.c
  WARNING: event parser found nothing
  invalid or unsupported event: 'tools/perf/examples/bpf/empty.c'
  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
  #

But, if we set things up to dump the generated object file to a file,
and do this after having run 'make install', still on the developer's
$HOME directory:

  # cat ~/.perfconfig
  [llvm]

	dump-obj = true
  #
  # perf trace -e ~acme/lib/examples/perf/bpf/empty.c
  LLVM: dumping /home/acme/lib/examples/perf/bpf/empty.o
  WARNING: event parser found nothing
  invalid or unsupported event: '/home/acme/lib/examples/perf/bpf/empty.c'
  <SNIP>
  #

We can look at the dumped object file:

  # ls -la ~acme/lib/examples/perf/bpf/empty.o
  -rw-r--r--. 1 root root 576 May  4 12:10 /home/acme/lib/examples/perf/bpf/empty.o
  # file ~acme/lib/examples/perf/bpf/empty.o
  /home/acme/lib/examples/perf/bpf/empty.o: ELF 64-bit LSB relocatable, *unknown arch 0xf7* version 1 (SYSV), not stripped
  # readelf -sw ~acme/lib/examples/perf/bpf/empty.o

  Symbol table '.symtab' contains 3 entries:
     Num:    Value          Size Type    Bind   Vis      Ndx Name
       0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
       1: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT    3 _license
       2: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT    4 _version
  #
  # tools/bpf/bpftool/bpftool --pretty ~acme/lib/examples/perf/bpf/empty.o
  null
  #

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-y7dkhakejz3013o0w21n98xd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2018-05-15 14:31:23 -03:00