| Message ID | 20240909201652.319406-5-mathieu.desnoyers@efficios.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tracing: Allow system call tracepoints to handle page faults | expand |
On Mon, Sep 9, 2024 at 1:17 PM Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > In preparation for allowing system call enter/exit instrumentation to > handle page faults, make sure that bpf can handle this change by > explicitly disabling preemption within the bpf system call tracepoint > probes to respect the current expectations within bpf tracing code. > > This change does not yet allow bpf to take page faults per se within its > probe, but allows its existing probes to adapt to the upcoming change. > > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Cc: Michael Jeanson <mjeanson@efficios.com> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Masami Hiramatsu <mhiramat@kernel.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Alexei Starovoitov <ast@kernel.org> > Cc: Yonghong Song <yhs@fb.com> > Cc: Paul E. McKenney <paulmck@kernel.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Arnaldo Carvalho de Melo <acme@kernel.org> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> > Cc: bpf@vger.kernel.org > Cc: Joel Fernandes <joel@joelfernandes.org> > --- > include/trace/bpf_probe.h | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > LGTM. Acked-by: Andrii Nakryiko <andrii@kernel.org> > diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h > index c85bbce5aaa5..211b98d45fc6 100644 > --- a/include/trace/bpf_probe.h > +++ b/include/trace/bpf_probe.h > @@ -53,8 +53,17 @@ __bpf_trace_##call(void *__data, proto) \ > #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ > __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) > > +#define __BPF_DECLARE_TRACE_SYSCALL(call, proto, args) \ > +static notrace void \ > +__bpf_trace_##call(void *__data, proto) \ > +{ \ > + guard(preempt_notrace)(); \ > + CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args)); \ > +} > + > #undef DECLARE_EVENT_SYSCALL_CLASS > -#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS > +#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \ > + __BPF_DECLARE_TRACE_SYSCALL(call, PARAMS(proto), PARAMS(args)) > > /* > * This part is compiled out, it is only here as a build time check > -- > 2.39.2 >
diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h index c85bbce5aaa5..211b98d45fc6 100644 --- a/include/trace/bpf_probe.h +++ b/include/trace/bpf_probe.h @@ -53,8 +53,17 @@ __bpf_trace_##call(void *__data, proto) \ #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) +#define __BPF_DECLARE_TRACE_SYSCALL(call, proto, args) \ +static notrace void \ +__bpf_trace_##call(void *__data, proto) \ +{ \ + guard(preempt_notrace)(); \ + CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args)); \ +} + #undef DECLARE_EVENT_SYSCALL_CLASS -#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS +#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \ + __BPF_DECLARE_TRACE_SYSCALL(call, PARAMS(proto), PARAMS(args)) /* * This part is compiled out, it is only here as a build time check
In preparation for allowing system call enter/exit instrumentation to handle page faults, make sure that bpf can handle this change by explicitly disabling preemption within the bpf system call tracepoint probes to respect the current expectations within bpf tracing code. This change does not yet allow bpf to take page faults per se within its probe, but allows its existing probes to adapt to the upcoming change. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michael Jeanson <mjeanson@efficios.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: bpf@vger.kernel.org Cc: Joel Fernandes <joel@joelfernandes.org> --- include/trace/bpf_probe.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)