From: Peter Zijlstra <peterz@infradead.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org,
Michael Jeanson <mjeanson@efficios.com>,
Alexei Starovoitov <ast@kernel.org>, Yonghong Song <yhs@fb.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
bpf@vger.kernel.org, Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH v4 2/5] tracing/ftrace: Add support for faultable tracepoints
Date: Mon, 20 Nov 2023 23:15:24 +0100 [thread overview]
Message-ID: <20231120221524.GD8262@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20231120205418.334172-3-mathieu.desnoyers@efficios.com>
On Mon, Nov 20, 2023 at 03:54:15PM -0500, Mathieu Desnoyers wrote:
> @@ -380,8 +415,8 @@ static inline notrace int trace_event_get_offsets_##call( \
>
> #include "stages/stage6_event_callback.h"
>
> -#undef DECLARE_EVENT_CLASS
> -#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
> +#undef _DECLARE_EVENT_CLASS
> +#define _DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print, tp_flags) \
> \
> static notrace void \
> trace_event_raw_event_##call(void *__data, proto) \
> @@ -392,8 +427,13 @@ trace_event_raw_event_##call(void *__data, proto) \
> struct trace_event_raw_##call *entry; \
> int __data_size; \
> \
> + if ((tp_flags) & TRACEPOINT_MAY_FAULT) { \
> + might_fault(); \
> + preempt_disable_notrace(); \
> + } \
> + \
> if (trace_trigger_soft_disabled(trace_file)) \
> - return; \
> + goto end; \
> \
> __data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
> \
> @@ -401,14 +441,28 @@ trace_event_raw_event_##call(void *__data, proto) \
> sizeof(*entry) + __data_size); \
> \
> if (!entry) \
> - return; \
> + goto end; \
> \
> tstruct \
> \
> { assign; } \
> \
> trace_event_buffer_commit(&fbuffer); \
> +end: \
> + if ((tp_flags) & TRACEPOINT_MAY_FAULT) \
> + preempt_enable_notrace(); \
> }
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 82cb22ad6d61..954f87515668 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -532,9 +532,16 @@ int trace_event_reg(struct trace_event_call *call,
> WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
> switch (type) {
> case TRACE_REG_REGISTER:
> - return tracepoint_probe_register(call->tp,
> - call->class->probe,
> - file);
> + if (call->tp->flags & TRACEPOINT_MAY_FAULT)
> + return tracepoint_probe_register_prio_flags(call->tp,
> + call->class->probe,
> + file,
> + TRACEPOINT_DEFAULT_PRIO,
> + TRACEPOINT_MAY_FAULT);
> + else
> + return tracepoint_probe_register(call->tp,
> + call->class->probe,
> + file);
> case TRACE_REG_UNREGISTER:
> tracepoint_probe_unregister(call->tp,
> call->class->probe,
> @@ -543,9 +550,16 @@ int trace_event_reg(struct trace_event_call *call,
>
> #ifdef CONFIG_PERF_EVENTS
> case TRACE_REG_PERF_REGISTER:
> - return tracepoint_probe_register(call->tp,
> - call->class->perf_probe,
> - call);
> + if (call->tp->flags & TRACEPOINT_MAY_FAULT)
> + return tracepoint_probe_register_prio_flags(call->tp,
> + call->class->perf_probe,
> + call,
> + TRACEPOINT_DEFAULT_PRIO,
> + TRACEPOINT_MAY_FAULT);
> + else
> + return tracepoint_probe_register(call->tp,
> + call->class->perf_probe,
> + call);
> case TRACE_REG_PERF_UNREGISTER:
> tracepoint_probe_unregister(call->tp,
> call->class->perf_probe,
I think something like the below (which is on top of the cleanup patch
in tip/locking/core) might just do...
---
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index c2d09bc4f976..37cbdb19d81d 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -151,7 +151,9 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \
#define DEFINE_GUARD(_name, _type, _lock, _unlock) \
DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \
static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \
- { return *_T; }
+ { return *_T; } \
+ static inline class_##_name##_t class_##_name##_null(void) \
+ { return NULL; }
#define DEFINE_GUARD_COND(_name, _ext, _condlock) \
EXTEND_CLASS(_name, _ext, \
@@ -175,6 +177,17 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \
if (!__guard_ptr(_name)(&scope)) _fail; \
else
+
+#define __guard_if(_cond, _name, var) \
+ class_##_name##_t var __cleanup(class_##_name##_destructor) = \
+ class_##_name##_null(); \
+ if (_cond) \
+ var = class_##_name##_constructor
+
+#define guard_if(_cond, _name) \
+ __guard_if(_cond, _name, __UNIQUE_ID(guard))
+
+
/*
* Additional helper macros for generating lock guards with types, either for
* locks that don't have a native type (eg. RCU, preempt) or those that need a
@@ -209,6 +222,12 @@ static inline void class_##_name##_destructor(class_##_name##_t *_T) \
static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \
{ \
return _T->lock; \
+} \
+ \
+static inline class_##_name##_t class_##_name##_null(void) \
+{ \
+ class_##_name##_t _t = { }; \
+ return _t; \
}
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 558af4960157..8e063c9846e0 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -427,13 +427,10 @@ trace_event_raw_event_##call(void *__data, proto) \
struct trace_event_raw_##call *entry; \
int __data_size; \
\
- if ((tp_flags) & TRACEPOINT_MAY_FAULT) { \
- might_fault(); \
- preempt_disable_notrace(); \
- } \
+ guard_if((tp_flags) & TRACEPOINT_MAY_FAULT, preempt_notrace)(); \
\
if (trace_trigger_soft_disabled(trace_file)) \
- goto end; \
+ return; \
\
__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
\
@@ -441,16 +438,13 @@ trace_event_raw_event_##call(void *__data, proto) \
sizeof(*entry) + __data_size); \
\
if (!entry) \
- goto end; \
+ return; \
\
tstruct \
\
{ assign; } \
\
trace_event_buffer_commit(&fbuffer); \
-end: \
- if ((tp_flags) & TRACEPOINT_MAY_FAULT) \
- preempt_enable_notrace(); \
}
#undef DECLARE_EVENT_CLASS
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index bf53d0d3eef9..09aec5db2e74 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -532,16 +532,11 @@ int trace_event_reg(struct trace_event_call *call,
WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
switch (type) {
case TRACE_REG_REGISTER:
- if (call->tp->flags & TRACEPOINT_MAY_FAULT)
- return tracepoint_probe_register_prio_flags(call->tp,
- call->class->probe,
- file,
- TRACEPOINT_DEFAULT_PRIO,
- TRACEPOINT_MAY_FAULT);
- else
- return tracepoint_probe_register(call->tp,
- call->class->probe,
- file);
+ return tracepoint_probe_register_prio_flags(call->tp,
+ call->class->probe,
+ file,
+ TRACEPOINT_DEFAULT_PRIO,
+ call->tp->flags & TRACEPOINT_MAY_FAULT);
case TRACE_REG_UNREGISTER:
tracepoint_probe_unregister(call->tp,
call->class->probe,
@@ -550,16 +545,11 @@ int trace_event_reg(struct trace_event_call *call,
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
- if (call->tp->flags & TRACEPOINT_MAY_FAULT)
- return tracepoint_probe_register_prio_flags(call->tp,
- call->class->perf_probe,
- call,
- TRACEPOINT_DEFAULT_PRIO,
- TRACEPOINT_MAY_FAULT);
- else
- return tracepoint_probe_register(call->tp,
- call->class->perf_probe,
- call);
+ return tracepoint_probe_register_prio_flags(call->tp,
+ call->class->perf_probe,
+ call,
+ TRACEPOINT_DEFAULT_PRIO,
+ call->tp->flags & TRACEPOINT_MAY_FAULT);
case TRACE_REG_PERF_UNREGISTER:
tracepoint_probe_unregister(call->tp,
call->class->perf_probe,
next prev parent reply other threads:[~2023-11-20 22:15 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-20 20:54 [PATCH v4 0/5] Faultable Tracepoints Mathieu Desnoyers
2023-11-20 20:54 ` [PATCH v4 1/5] tracing: Introduce faultable tracepoints Mathieu Desnoyers
2023-11-20 21:47 ` Peter Zijlstra
2023-11-20 22:18 ` Paul E. McKenney
2023-11-20 22:23 ` Peter Zijlstra
2023-11-20 23:56 ` Paul E. McKenney
2023-11-21 8:47 ` Peter Zijlstra
2023-11-21 14:06 ` Mathieu Desnoyers
2023-11-21 14:36 ` Peter Zijlstra
2023-11-21 14:40 ` Mathieu Desnoyers
2023-11-21 14:46 ` Peter Zijlstra
2023-11-21 14:56 ` Mathieu Desnoyers
2023-11-21 15:51 ` Paul E. McKenney
2023-11-21 15:52 ` Peter Zijlstra
2023-11-21 16:00 ` Mathieu Desnoyers
2023-11-21 16:07 ` Steven Rostedt
2023-11-21 16:11 ` Mathieu Desnoyers
2023-11-21 16:43 ` Paul E. McKenney
2023-11-21 16:50 ` Peter Zijlstra
2023-11-21 17:31 ` Peter Zijlstra
2023-11-21 16:41 ` Paul E. McKenney
2023-11-21 14:44 ` Steven Rostedt
2023-11-21 16:45 ` Paul E. McKenney
2023-11-21 15:58 ` Paul E. McKenney
2023-11-21 16:03 ` Peter Zijlstra
2023-11-21 16:46 ` Paul E. McKenney
2023-11-20 22:20 ` Steven Rostedt
2024-06-20 15:38 ` Mathieu Desnoyers
2023-11-20 20:54 ` [PATCH v4 2/5] tracing/ftrace: Add support for " Mathieu Desnoyers
2023-11-20 22:15 ` Peter Zijlstra [this message]
2024-06-20 15:04 ` Mathieu Desnoyers
2023-11-20 20:54 ` [PATCH v4 3/5] tracing/bpf-trace: add " Mathieu Desnoyers
2023-11-20 20:54 ` [PATCH v4 4/5] tracing/perf: " Mathieu Desnoyers
2023-11-20 20:54 ` [PATCH v4 5/5] tracing: convert sys_enter/exit to " Mathieu Desnoyers
2023-11-20 21:46 ` Peter Zijlstra
2024-06-20 15:05 ` Mathieu Desnoyers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231120221524.GD8262@noisy.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=joel@joelfernandes.org \
--cc=jolsa@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=mjeanson@efficios.com \
--cc=namhyung@kernel.org \
--cc=paulmck@kernel.org \
--cc=rostedt@goodmis.org \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.