• Arnaldo Carvalho de Melo's avatar
    perf bpf: Add 'syscall_enter' probe helper for syscall enter tracepoints · dda9ac96
    Arnaldo Carvalho de Melo authored
    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.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
sys_enter_openat.c 764 Bytes