diff options
| -rw-r--r-- | Documentation/bpf/bpf_design_QA.rst | 6 | ||||
| -rw-r--r-- | include/trace/bpf_probe.h | 12 |
2 files changed, 16 insertions, 2 deletions
diff --git a/Documentation/bpf/bpf_design_QA.rst b/Documentation/bpf/bpf_design_QA.rst index 2df7b067ab93..0e15f9b05c9d 100644 --- a/Documentation/bpf/bpf_design_QA.rst +++ b/Documentation/bpf/bpf_design_QA.rst @@ -208,6 +208,12 @@ data structures and compile with kernel internal headers. Both of these kernel internals are subject to change and can break with newer kernels such that the program needs to be adapted accordingly. +Q: Are tracepoints part of the stable ABI? +------------------------------------------ +A: NO. Tracepoints are tied to internal implementation details hence they are +subject to change and can break with newer kernels. BPF programs need to change +accordingly when this happens. + Q: How much stack space a BPF program uses? ------------------------------------------- A: Currently all program types are limited to 512 bytes of stack diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h index cd74bffed5c6..a23be89119aa 100644 --- a/include/trace/bpf_probe.h +++ b/include/trace/bpf_probe.h @@ -55,8 +55,7 @@ /* tracepoints with more than 12 arguments will hit build error */ #define CAST_TO_U64(...) CONCATENATE(__CAST, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__) -#undef DECLARE_EVENT_CLASS -#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ +#define __BPF_DECLARE_TRACE(call, proto, args) \ static notrace void \ __bpf_trace_##call(void *__data, proto) \ { \ @@ -64,6 +63,10 @@ __bpf_trace_##call(void *__data, proto) \ CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(prog, CAST_TO_U64(args)); \ } +#undef DECLARE_EVENT_CLASS +#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ + __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) + /* * This part is compiled out, it is only here as a build time check * to make sure that if the tracepoint handling changes, the @@ -111,6 +114,11 @@ __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size) #define DEFINE_EVENT_PRINT(template, name, proto, args, print) \ DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args)) +#undef DECLARE_TRACE +#define DECLARE_TRACE(call, proto, args) \ + __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \ + __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), 0) + #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) #undef DEFINE_EVENT_WRITABLE |