From 822c2621daadcf9e8fa8f11f7334e3c349434154 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 1 Aug 2018 10:50:51 -0300 Subject: [PATCH] perf bpf: Include uapi/linux/bpf.h from the 'perf trace' script's bpf.h The next example scripts need the definition for the BPF functions, i.e. things like BPF_FUNC_probe_read, and in time will require lots of other definitions found in uapi/linux/bpf.h, so include it from the bpf.h file included from the eBPF scripts build with clang via '-e bpf_script.c' like in this example: $ tail -8 tools/perf/examples/bpf/5sec.c #include int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec) { return sec == 5; } license(GPL); $ That 'bpf.h' include in the 5sec.c eBPF example will come from a set of header files crafted for building eBPF objects, that in a end-user system will come from: /usr/lib/perf/include/bpf/bpf.h And will include either from the place where the kernel was built, or from a kernel-devel rpm package like: -working-directory /lib/modules/4.17.9-100.fc27.x86_64/build That is set up by tools/perf/util/llvm-utils.c, and can be overriden by setting the 'kbuild-dir' variable in the "llvm" ~/.perfconfig file, like: # cat ~/.perfconfig [llvm] kbuild-dir = /home/foo/git/build/linux This usually doesn't need any change, just documenting here my findings while working with this code. In the future we may want to instead just use what is in /usr/include/linux/bpf.h, that comes from the UAPI provided from the kernel sources, for now, to avoid getting the kernel's non-UAPI "linux/bpf.h" file, that will cause clang to fail and is not what we want anyway (no BPF function definitions, etc), do it explicitely by asking for "uapi/linux/bpf.h". Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-zd8zeyhr2sappevojdem9xxt@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/include/bpf/bpf.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/perf/include/bpf/bpf.h b/tools/perf/include/bpf/bpf.h index dd764ad..a63aa62 100644 --- a/tools/perf/include/bpf/bpf.h +++ b/tools/perf/include/bpf/bpf.h @@ -1,6 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 #ifndef _PERF_BPF_H #define _PERF_BPF_H + +#include + #define SEC(NAME) __attribute__((section(NAME), used)) #define probe(function, vars) \ -- 2.7.4