linux/tools/perf/examples, branch v5.0

perf augmented_raw_syscalls: Copy 'access' arg as well

2018-12-18T19:15:18Z

This will all come from userspace, but to test the changes to make 'perf trace' output similar to strace's, do this one more now manually. To update the precompiled augmented_raw_syscalls.o binary I just run: # perf record -e ~acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1 LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.022 MB perf.data ] # Because to have augmented_raw_syscalls to be always used and a fast startup and remove the need to have the llvm toolchain installed, I'm using: # perf config | grep add_events trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o # So when doing changes to augmented_raw_syscals.c one needs to rebuild the .o file. This will be done automagically later, i.e. have a 'make' behaviour of recompiling when the .c gets changed. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-lw3i2atyq8549fpqwmszn3qp@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_raw_syscalls: Do not include stdio.h

2018-12-18T15:24:00Z

We're not using that puts() thing, and thus we don't need to define the __bpf_stdout__ map, reducing the setup time. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-3452xgatncpil7v22minkwbo@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_syscalls: Switch to using a struct for the syscalls map values

2018-12-18T15:23:58Z

We'll start adding more perf-syscall stuff, so lets do this prep step so that the next ones are just about adding more fields. Run it with the .c file once to cache the .o file: # trace --filter-pids 2834,2199 -e openat,augmented_raw_syscalls.c LLVM: dumping augmented_raw_syscalls.o 0.000 ( 0.021 ms): tmux: server/4952 openat(dfd: CWD, filename: /proc/5691/cmdline ) = 11 349.807 ( 0.040 ms): DNS Res~er #39/11082 openat(dfd: CWD, filename: /etc/hosts, flags: CLOEXEC ) = 44 4988.759 ( 0.052 ms): gsd-color/2431 openat(dfd: CWD, filename: /etc/localtime ) = 18 4988.976 ( 0.029 ms): gsd-color/2431 openat(dfd: CWD, filename: /etc/localtime ) = 18 ^C[root@quaco bpf]# From now on, we can use just the newly built .o file, skipping the compilation step for a faster startup: # trace --filter-pids 2834,2199 -e openat,augmented_raw_syscalls.o 0.000 ( 0.046 ms): DNS Res~er #39/11088 openat(dfd: CWD, filename: /etc/hosts, flags: CLOEXEC ) = 44 1946.408 ( 0.190 ms): systemd/1 openat(dfd: CWD, filename: /proc/1071/cgroup, flags: CLOEXEC ) = 20 1946.792 ( 0.215 ms): systemd/1 openat(dfd: CWD, filename: /proc/954/cgroup, flags: CLOEXEC ) = 20 ^C# Now on to do the same in the builtin-trace.c side of things. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-k8mwu04l8es29rje5loq9vg7@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Implement syscall filtering in augmented_syscalls

2018-12-18T15:23:58Z

Just another map, this time an BPF_MAP_TYPE_ARRAY, stating with one bool per syscall, stating if it should be filtered or not. So, with a pre-built augmented_raw_syscalls.o file, we use: # perf trace -e open*,augmented_raw_syscalls.o 0.000 ( 0.016 ms): DNS Res~er #37/29652 openat(dfd: CWD, filename: /etc/hosts, flags: CLOEXEC ) = 138 187.039 ( 0.048 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC ) = 11 187.348 ( 0.041 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11 188.793 ( 0.036 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11 189.803 ( 0.029 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11 190.774 ( 0.027 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11 284.620 ( 0.149 ms): DataStorage/3076 openat(dfd: CWD, filename: /home/acme/.mozilla/firefox/ina67tev.default/SiteSecurityServiceState.txt, flags: CREAT|TRUNC|WRONLY, mode: IRUGO|IWUSR|IWGRP) = 167 ^C# What is it that this gsd-housekeeping thingy needs to open /proc/self/mountinfo four times periodically? :-) This map will be extended to tell per-syscall parameters, i.e. how many bytes to copy per arg, using the function signature to get the types and then the size of those types, via BTF. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-cy222g9ucvnym3raqvxp0hpg@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

Revert "perf augmented_syscalls: Drop 'write', 'poll' for testing without self pid filter"

2018-11-21T15:00:31Z

Now that we have the "filtered_pids" logic in place, no need to do this rough filter to avoid the feedback loop from 'perf trace's own syscalls, revert it. This reverts commit 7ed71f124284359676b6496ae7db724fee9da753. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-88vh02cnkam0vv5f9vp02o3h@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_syscalls: Remove example hardcoded set of filtered pids

2018-11-21T15:00:31Z

Now that 'perf trace' fills in that "filtered_pids" BPF map, remove the set of filtered pids used as an example to test that feature. That feature works like this: Starting a system wide 'strace' like 'perf trace' augmented session we noticed that lots of events take place for a pid, which ends up being the feedback loop of perf trace's syscalls being processed by the 'gnome-terminal' process: # perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c 0.391 ( 0.002 ms): gnome-terminal/2469 read(fd: 17, buf: 0x564b79f750bc, count: 8176) = 453 0.394 ( 0.001 ms): gnome-terminal/2469 read(fd: 17, buf: 0x564b79f75280, count: 7724) = -1 EAGAIN Resource temporarily unavailable 0.438 ( 0.001 ms): gnome-terminal/2469 read(fd: 4, buf: 0x7fffc696aeb0, count: 16) = 8 0.519 ( 0.001 ms): gnome-terminal/2469 read(fd: 17, buf: 0x564b79f75280, count: 7724) = 114 0.522 ( 0.001 ms): gnome-terminal/2469 read(fd: 17, buf: 0x564b79f752f1, count: 7611) = -1 EAGAIN Resource temporarily unavailable ^C So we can use --filter-pids to get rid of that one, and in this case what is being used to implement that functionality is that "filtered_pids" BPF map that the tools/perf/examples/bpf/augmented_raw_syscalls.c created and that 'perf trace' bpf loader noticed and created a "struct bpf_map" associated that then got populated by 'perf trace': # perf trace --filter-pids 2469 -e tools/perf/examples/bpf/augmented_raw_syscalls.c 0.020 ( 0.002 ms): gnome-shell/1663 epoll_pwait(epfd: 12, events: 0x7ffd8f3ef960, maxevents: 32, sigsetsize: 8) = 1 0.025 ( 0.002 ms): gnome-shell/1663 read(fd: 24, buf: 0x560c01bb8240, count: 8112) = 48 0.029 ( 0.001 ms): gnome-shell/1663 read(fd: 24, buf: 0x560c01bb8258, count: 8088) = -1 EAGAIN Resource temporarily unavailable 0.032 ( 0.001 ms): gnome-shell/1663 read(fd: 24, buf: 0x560c01bb8240, count: 8112) = -1 EAGAIN Resource temporarily unavailable 0.040 ( 0.003 ms): gnome-shell/1663 recvmsg(fd: 46, msg: 0x7ffd8f3ef950) = -1 EAGAIN Resource temporarily unavailable 21.529 ( 0.002 ms): gnome-shell/1663 epoll_pwait(epfd: 5, events: 0x7ffd8f3ef960, maxevents: 32, sigsetsize: 8) = 1 21.533 ( 0.004 ms): gnome-shell/1663 recvmsg(fd: 82, msg: 0x7ffd8f3ef7b0, flags: DONTWAIT|CMSG_CLOEXEC) = 236 21.581 ( 0.006 ms): gnome-shell/1663 ioctl(fd: 8, cmd: DRM_I915_GEM_BUSY, arg: 0x7ffd8f3ef060) = 0 21.605 ( 0.020 ms): gnome-shell/1663 ioctl(fd: 8, cmd: DRM_I915_GEM_CREATE, arg: 0x7ffd8f3eeea0) = 0 21.626 ( 0.119 ms): gnome-shell/1663 ioctl(fd: 8, cmd: DRM_I915_GEM_SET_DOMAIN, arg: 0x7ffd8f3eee94) = 0 21.746 ( 0.081 ms): gnome-shell/1663 ioctl(fd: 8, cmd: DRM_I915_GEM_PWRITE, arg: 0x7ffd8f3eeea0) = 0 ^C Oops, yet another gnome process that is involved with the output that 'perf trace' generates, lets filter that out too: # perf trace --filter-pids 2469,1663 -e tools/perf/examples/bpf/augmented_raw_syscalls.c ? ( ): wpa_supplicant/1366 ... [continued]: select()) = 0 Timeout 0.006 ( 0.002 ms): wpa_supplicant/1366 clock_gettime(which_clock: BOOTTIME, tp: 0x7fffe5b1e430) = 0 0.011 ( 0.001 ms): wpa_supplicant/1366 clock_gettime(which_clock: BOOTTIME, tp: 0x7fffe5b1e3e0) = 0 0.014 ( 0.001 ms): wpa_supplicant/1366 clock_gettime(which_clock: BOOTTIME, tp: 0x7fffe5b1e430) = 0 ? ( ): gmain/1791 ... [continued]: poll()) = 0 Timeout 0.017 ( ): wpa_supplicant/1366 select(n: 6, inp: 0x55646fed3ad0, outp: 0x55646fed3b60, exp: 0x55646fed3bf0, tvp: 0x7fffe5b1e4a0) ... 157.879 ( 0.019 ms): gmain/1791 inotify_add_watch(fd: 8, pathname: , mask: 16789454) = -1 ENOENT No such file or directory ? ( ): cupsd/1001 ... [continued]: epoll_pwait()) = 0 ? ( ): gsd-color/1908 ... [continued]: poll()) = 0 Timeout 499.615 ( ): cupsd/1001 epoll_pwait(epfd: 4, events: 0x557a21166500, maxevents: 4096, timeout: 1000, sigsetsize: 8) ... 586.593 ( 0.004 ms): gsd-color/1908 recvmsg(fd: 3, msg: 0x7ffdef34e800) = -1 EAGAIN Resource temporarily unavailable ? ( ): fwupd/2230 ... [continued]: poll()) = 0 Timeout ? ( ): rtkit-daemon/906 ... [continued]: poll()) = 0 Timeout ? ( ): rtkit-daemon/907 ... [continued]: poll()) = 1 724.603 ( 0.007 ms): rtkit-daemon/907 read(fd: 6, buf: 0x7f05ff768d08, count: 8) = 8 ? ( ): ssh/5461 ... [continued]: select()) = 1 810.431 ( 0.002 ms): ssh/5461 clock_gettime(which_clock: BOOTTIME, tp: 0x7ffd7f39f870) = 0 ^C Several syscall exit events for syscalls in flight when 'perf trace' started, etc. Saner :-) Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-c3tu5yg204p5mvr9kvwew07n@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_syscalls: Use pid_filter

2018-11-21T15:00:31Z

Just to test filtering a bunch of pids, now its time to go and get that hooked up in 'perf trace', right after we load the bpf program, if we find a "pids_filtered" map defined, we'll populate it with the filtered pids. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-1i9s27wqqdhafk3fappow84x@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_syscalls: Drop 'write', 'poll' for testing without self pid filter

2018-11-21T15:00:31Z

When testing system wide tracing without filtering the syscalls called by 'perf trace' itself we get into a feedback loop, drop for now those two syscalls, that are the ones that 'perf trace' does in its loop for writing the syscalls it intercepts, to help with testing till we get that filtering in place. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-rkbu536af66dbsfx51sr8yof@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_syscalls: Remove needless linux/socket.h include

2018-11-21T15:00:31Z

Leftover from when we started augmented_raw_syscalls.c from tools/perf/examples/bpf/augmented_syscalls. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Fixes: e58a0322dbac ("perf examples bpf: Start augmenting raw_syscalls:sys_{start,exit}") Link: https://lkml.kernel.org/n/tip-pmts9ls2skh8n3zisb4txudd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf augmented_syscalls: Filter on a hard coded pid

2018-11-21T15:00:31Z

Just to show where we'll hook pid based filters, and what we use to obtain the current pid, using a BPF getpid() equivalent. Now we need to remove that hardcoded PID with a BPF hash map, so that we start by filtering 'perf trace's own PID, implement the --filter-pid functionality, etc. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-oshrcgcekiyhd0whwisxfvtv@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo