The bpf.h file needed gets installed in /usr/lib/include/perf/bpf/bpf.h,
and /usr/lib/include/perf/ is added to the include path passed to clang
to build the eBPF bytecode, so just remove "bpf/", its directly in the
path passed already. This was working by accident, fix it.
I.e. now this is back working:
# cat /home/acme/git/perf/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 /home/acme/git/perf/tools/perf/examples/bpf/hello.c
0.000 pickup/21493 __bpf_stdout__(Hello, world)
56.462 sh/13539 __bpf_stdout__(Hello, world)
56.536 sh/13539 __bpf_stdout__(Hello, world)
56.673 sh/13539 __bpf_stdout__(Hello, world)
56.781 sh/13539 __bpf_stdout__(Hello, world)
56.707 perf/13182 __bpf_stdout__(Hello, world)
56.849 perf/13182 __bpf_stdout__(Hello, world)
^C
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-d9myswhgo8gfi3vmehdqpxa7@git.kernel.org
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
So that we don't always carry that __bpf_output__ map, leaving that to
the scripts wanting to use that facility.
'perf trace' will be changed to look if that map is present and only
setup the bpf-output events if so.
Cc: Adrian Hunter <adrian.hunter@intel.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-azwys8irxqx9053vpajr0k5h@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
Arnaldo Carvalho de Melo