• Arnaldo Carvalho de Melo's avatar
    perf examples bpf: Start augmenting raw_syscalls:sys_{start,exit} · febf8a37
    Arnaldo Carvalho de Melo authored
    The previous approach of attaching to each syscall showed how it is
    possible to augment tracepoints and use that augmentation, pointer
    payloads, in the existing beautifiers in 'perf trace', but for a more
    general solution we now will try to augment the main
    raw_syscalls:sys_{enter,exit} syscalls, and then pass instructions in
    maps so that it knows which syscalls and which pointer contents, and how
    many bytes for each of the arguments should be copied.
    
    Start with just the bare minimum to collect what is provided by those
    two tracepoints via the __augmented_syscalls__ map + bpf-output perf
    event, which results in perf trace showing them without connecting
    enter+exit:
    
      # perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1
         0.000 sleep/11563 raw_syscalls:sys_exit:NR 59 = 0
         0.019 (         ): sleep/11563 brk() ...
         0.021 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642325504
         0.033 (         ): sleep/11563 access(filename:, mode: R) ...
         0.037 sleep/11563 raw_syscalls:sys_exit:NR 21 = -2
         0.041 (         ): sleep/11563 openat(dfd: CWD, filename: , flags: CLOEXEC) ...
         0.044 sleep/11563 raw_syscalls:sys_exit:NR 257 = 3
         0.045 (         ): sleep/11563 fstat(fd: 3, statbuf: 0x7ffdbf7119b0) ...
         0.046 sleep/11563 raw_syscalls:sys_exit:NR 5 = 0
         0.047 (         ): sleep/11563 mmap(len: 103334, prot: READ, flags: PRIVATE, fd: 3) ...
         0.049 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196285493248
         0.050 (         ): sleep/11563 close(fd: 3) ...
         0.051 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
         0.059 (         ): sleep/11563 openat(dfd: CWD, filename: , flags: CLOEXEC) ...
         0.062 sleep/11563 raw_syscalls:sys_exit:NR 257 = 3
         0.063 (         ): sleep/11563 read(fd: 3, buf: 0x7ffdbf711b78, count: 832) ...
         0.065 sleep/11563 raw_syscalls:sys_exit:NR 0 = 832
         0.066 (         ): sleep/11563 fstat(fd: 3, statbuf: 0x7ffdbf711a10) ...
         0.067 sleep/11563 raw_syscalls:sys_exit:NR 5 = 0
         0.068 (         ): sleep/11563 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS) ...
         0.070 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196285485056
         0.073 (         ): sleep/11563 mmap(len: 3889792, prot: EXEC|READ, flags: PRIVATE|DENYWRITE, fd: 3) ...
         0.076 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196279463936
         0.077 (         ): sleep/11563 mprotect(start: 0x7f81fd8a8000, len: 2093056) ...
         0.083 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
         0.084 (         ): sleep/11563 mmap(addr: 0x7f81fdaa7000, len: 24576, prot: READ|WRITE, flags: PRIVATE|FIXED|DENYWRITE, fd: 3, off: 1753088) ...
         0.088 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196283314176
         0.091 (         ): sleep/11563 mmap(addr: 0x7f81fdaad000, len: 14976, prot: READ|WRITE, flags: PRIVATE|FIXED|ANONYMOUS) ...
         0.093 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196283338752
         0.097 (         ): sleep/11563 close(fd: 3) ...
         0.098 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
         0.107 (         ): sleep/11563 arch_prctl(option: 4098, arg2: 140196285490432) ...
         0.108 sleep/11563 raw_syscalls:sys_exit:NR 158 = 0
         0.143 (         ): sleep/11563 mprotect(start: 0x7f81fdaa7000, len: 16384, prot: READ) ...
         0.146 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
         0.157 (         ): sleep/11563 mprotect(start: 0x561d037e7000, len: 4096, prot: READ) ...
         0.160 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
         0.163 (         ): sleep/11563 mprotect(start: 0x7f81fdcd5000, len: 4096, prot: READ) ...
         0.165 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
         0.166 (         ): sleep/11563 munmap(addr: 0x7f81fdcbb000, len: 103334) ...
         0.174 sleep/11563 raw_syscalls:sys_exit:NR 11 = 0
         0.216 (         ): sleep/11563 brk() ...
         0.217 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642325504
         0.217 (         ): sleep/11563 brk(brk: 0x561d05453000) ...
         0.219 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642460672
         0.220 (         ): sleep/11563 brk() ...
         0.221 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642460672
         0.224 (         ): sleep/11563 open(filename: , flags: CLOEXEC) ...
         0.228 sleep/11563 raw_syscalls:sys_exit:NR 2 = 3
         0.229 (         ): sleep/11563 fstat(fd: 3, statbuf: 0x7f81fdaacaa0) ...
         0.230 sleep/11563 raw_syscalls:sys_exit:NR 5 = 0
         0.231 (         ): sleep/11563 mmap(len: 113045344, prot: READ, flags: PRIVATE, fd: 3) ...
         0.234 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196166418432
         0.237 (         ): sleep/11563 close(fd: 3) ...
         0.238 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
         0.262 (         ): sleep/11563 nanosleep(rqtp: 0x7ffdbf7126f0) ...
      1000.399 sleep/11563 raw_syscalls:sys_exit:NR 35 = 0
      1000.440 (         ): sleep/11563 close(fd: 1) ...
      1000.447 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
      1000.454 (         ): sleep/11563 close(fd: 2) ...
      1000.468 (         ): sleep/11563 exit_group(                                                           )
      #
    
    In the next csets we'll connect those events to the existing enter/exit
    raw_syscalls handlers in 'perf trace', just like we did with the
    syscalls:sys_{enter,exit}_* tracepoints.
    
    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-5nl8l4hx1tl9pqdx65nkp6pw@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    febf8a37
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