The examples were used to give demonstrations of BPF events but such
functionality is now subsumed by using --filter with 'perf record' or
the direct use of BPF skeletons.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wang ShaoBo <bobo.shaobowang@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230810184853.2860737-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Fix perf to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560797.1683545.7685921032671386301.stgit@toke.dk

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>