Re: [PATCH v3 2/2] rust: add tracepoint support
On Wed, Jun 26, 2024 at 8:43 PM Steven Rostedt wrote: > > On Wed, 26 Jun 2024 10:48:23 +0200 > Alice Ryhl wrote: > > > > > > > Because your hooks/rust_binder.h and events/rust_binder.h use the same > > > TRACE_SYSTEM name? Could you try something like: > > > > > > #define TRACE_SYSTEM rust_binder_hook > > > > > > in your hooks/rust_binder.h? > > > > I was able to get it to work by moving the includes into two different > > .c files. I don't think changing TRACE_SYSTEM works because it must > > match the filename. > > Try to use: > > #define TRACE_SYSTEM_VAR rust_binder_hook_other_name > > in one. Then that is used as the variable for that file. Thanks. I also made a change to restore the value of DEFINE_RUST_DO_TRACE after define_trace.h Alice
Re: [PATCH v3 2/2] rust: add tracepoint support
On Wed, 26 Jun 2024 10:48:23 +0200 Alice Ryhl wrote: > > > > Because your hooks/rust_binder.h and events/rust_binder.h use the same > > TRACE_SYSTEM name? Could you try something like: > > > > #define TRACE_SYSTEM rust_binder_hook > > > > in your hooks/rust_binder.h? > > I was able to get it to work by moving the includes into two different > .c files. I don't think changing TRACE_SYSTEM works because it must > match the filename. Try to use: #define TRACE_SYSTEM_VAR rust_binder_hook_other_name in one. Then that is used as the variable for that file. -- Steve
Re: [PATCH v3 2/2] rust: add tracepoint support
On Tue, Jun 25, 2024 at 8:11 PM Boqun Feng wrote: > > On Fri, Jun 21, 2024 at 02:52:10PM +0200, Alice Ryhl wrote: > [...] > > > > Hmm, I tried using the support where I have both events and hooks: > > > > #define CREATE_TRACE_POINTS > > #define CREATE_RUST_TRACE_POINTS > > #include > > #include > > > > But it's not really working. Initially I thought that it's because I > > need to undef DEFINE_RUST_DO_TRACE at the end of this file, but even > > when I added that, I still get this error: > > > > error: redefinition of 'str__rust_binder__trace_system_name' > > > > Is the Rust support missing something, or is the answer just that you > > can't have two files of the same name like this? Or am I doing > > something else wrong? > > > > Because your hooks/rust_binder.h and events/rust_binder.h use the same > TRACE_SYSTEM name? Could you try something like: > > #define TRACE_SYSTEM rust_binder_hook > > in your hooks/rust_binder.h? I was able to get it to work by moving the includes into two different .c files. I don't think changing TRACE_SYSTEM works because it must match the filename. Alice
Re: [PATCH v3 2/2] rust: add tracepoint support
On Fri, Jun 21, 2024 at 02:52:10PM +0200, Alice Ryhl wrote: [...] > > Hmm, I tried using the support where I have both events and hooks: > > #define CREATE_TRACE_POINTS > #define CREATE_RUST_TRACE_POINTS > #include > #include > > But it's not really working. Initially I thought that it's because I > need to undef DEFINE_RUST_DO_TRACE at the end of this file, but even > when I added that, I still get this error: > > error: redefinition of 'str__rust_binder__trace_system_name' > > Is the Rust support missing something, or is the answer just that you > can't have two files of the same name like this? Or am I doing > something else wrong? > Because your hooks/rust_binder.h and events/rust_binder.h use the same TRACE_SYSTEM name? Could you try something like: #define TRACE_SYSTEM rust_binder_hook in your hooks/rust_binder.h? Regards, Boqun > Alice
Re: [PATCH v3 2/2] rust: add tracepoint support
On Fri, Jun 21, 2024 at 12:35 PM Alice Ryhl wrote:
>
> Make it possible to have Rust code call into tracepoints defined by C
> code. It is still required that the tracepoint is declared in a C
> header, and that this header is included in the input to bindgen.
>
> Signed-off-by: Alice Ryhl
> ---
> include/linux/tracepoint.h | 18 +++-
> include/trace/define_trace.h| 7 ++
> rust/bindings/bindings_helper.h | 1 +
> rust/kernel/lib.rs | 1 +
> rust/kernel/tracepoint.rs | 47
> +
> 5 files changed, 73 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> index 689b6d71590e..d82af4d77c9f 100644
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -238,6 +238,20 @@ static inline struct tracepoint
> *tracepoint_ptr_deref(tracepoint_ptr_t *p)
> #define __DECLARE_TRACE_RCU(name, proto, args, cond)
> #endif
>
> +/*
> + * Declare an exported function that Rust code can call to trigger this
> + * tracepoint. This function does not include the static branch; that is done
> + * in Rust to avoid a function call when the tracepoint is disabled.
> + */
> +#define DEFINE_RUST_DO_TRACE(name, proto, args)
> +#define DEFINE_RUST_DO_TRACE_REAL(name, proto, args) \
> + notrace void rust_do_trace_##name(proto)\
> + { \
> + __DO_TRACE(name,\
> + TP_ARGS(args), \
> + cpu_online(raw_smp_processor_id()), 0); \
> + }
> +
> /*
> * Make sure the alignment of the structure in the __tracepoints section will
> * not add unwanted padding between the beginning of the section and the
> @@ -253,6 +267,7 @@ static inline struct tracepoint
> *tracepoint_ptr_deref(tracepoint_ptr_t *p)
> extern int __traceiter_##name(data_proto); \
> DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name);\
> extern struct tracepoint __tracepoint_##name; \
> + extern void rust_do_trace_##name(proto);\
> static inline void trace_##name(proto) \
> { \
> if (static_key_false(&__tracepoint_##name.key)) \
> @@ -337,7 +352,8 @@ static inline struct tracepoint
> *tracepoint_ptr_deref(tracepoint_ptr_t *p)
> void __probestub_##_name(void *__data, proto) \
> { \
> } \
> - DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
> + DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \
> + DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args))
>
> #define DEFINE_TRACE(name, proto, args)\
> DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args));
> diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
> index 00723935dcc7..b47cc036acba 100644
> --- a/include/trace/define_trace.h
> +++ b/include/trace/define_trace.h
> @@ -72,6 +72,13 @@
> #define DECLARE_TRACE(name, proto, args) \
> DEFINE_TRACE(name, PARAMS(proto), PARAMS(args))
>
> +/* If requested, create helpers for calling these tracepoints from Rust. */
> +#ifdef CREATE_RUST_TRACE_POINTS
> +#undef DEFINE_RUST_DO_TRACE
> +#define DEFINE_RUST_DO_TRACE(name, proto, args)\
> + DEFINE_RUST_DO_TRACE_REAL(name, PARAMS(proto), PARAMS(args))
> +#endif
> +
> #undef TRACE_INCLUDE
> #undef __TRACE_INCLUDE
>
> diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
Hmm, I tried using the support where I have both events and hooks:
#define CREATE_TRACE_POINTS
#define CREATE_RUST_TRACE_POINTS
#include
#include
But it's not really working. Initially I thought that it's because I
need to undef DEFINE_RUST_DO_TRACE at the end of this file, but even
when I added that, I still get this error:
error: redefinition of 'str__rust_binder__trace_system_name'
Is the Rust support missing something, or is the answer just that you
can't have two files of the same name like this? Or am I doing
something else wrong?
Alice
[PATCH v3 2/2] rust: add tracepoint support
Make it possible to have Rust code call into tracepoints defined by C
code. It is still required that the tracepoint is declared in a C
header, and that this header is included in the input to bindgen.
Signed-off-by: Alice Ryhl
---
include/linux/tracepoint.h | 18 +++-
include/trace/define_trace.h| 7 ++
rust/bindings/bindings_helper.h | 1 +
rust/kernel/lib.rs | 1 +
rust/kernel/tracepoint.rs | 47 +
5 files changed, 73 insertions(+), 1 deletion(-)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 689b6d71590e..d82af4d77c9f 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -238,6 +238,20 @@ static inline struct tracepoint
*tracepoint_ptr_deref(tracepoint_ptr_t *p)
#define __DECLARE_TRACE_RCU(name, proto, args, cond)
#endif
+/*
+ * Declare an exported function that Rust code can call to trigger this
+ * tracepoint. This function does not include the static branch; that is done
+ * in Rust to avoid a function call when the tracepoint is disabled.
+ */
+#define DEFINE_RUST_DO_TRACE(name, proto, args)
+#define DEFINE_RUST_DO_TRACE_REAL(name, proto, args) \
+ notrace void rust_do_trace_##name(proto)\
+ { \
+ __DO_TRACE(name,\
+ TP_ARGS(args), \
+ cpu_online(raw_smp_processor_id()), 0); \
+ }
+
/*
* Make sure the alignment of the structure in the __tracepoints section will
* not add unwanted padding between the beginning of the section and the
@@ -253,6 +267,7 @@ static inline struct tracepoint
*tracepoint_ptr_deref(tracepoint_ptr_t *p)
extern int __traceiter_##name(data_proto); \
DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name);\
extern struct tracepoint __tracepoint_##name; \
+ extern void rust_do_trace_##name(proto);\
static inline void trace_##name(proto) \
{ \
if (static_key_false(&__tracepoint_##name.key)) \
@@ -337,7 +352,8 @@ static inline struct tracepoint
*tracepoint_ptr_deref(tracepoint_ptr_t *p)
void __probestub_##_name(void *__data, proto) \
{ \
} \
- DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
+ DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \
+ DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args))
#define DEFINE_TRACE(name, proto, args)\
DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args));
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 00723935dcc7..b47cc036acba 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -72,6 +72,13 @@
#define DECLARE_TRACE(name, proto, args) \
DEFINE_TRACE(name, PARAMS(proto), PARAMS(args))
+/* If requested, create helpers for calling these tracepoints from Rust. */
+#ifdef CREATE_RUST_TRACE_POINTS
+#undef DEFINE_RUST_DO_TRACE
+#define DEFINE_RUST_DO_TRACE(name, proto, args)\
+ DEFINE_RUST_DO_TRACE_REAL(name, PARAMS(proto), PARAMS(args))
+#endif
+
#undef TRACE_INCLUDE
#undef __TRACE_INCLUDE
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index ddb5644d4fd9..d442f9ccfc2c 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#include
#include
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index a0be9544996d..96f8f11c51f2 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -45,6 +45,7 @@
pub mod sync;
pub mod task;
pub mod time;
+pub mod tracepoint;
pub mod types;
pub mod workqueue;
diff --git a/rust/kernel/tracepoint.rs b/rust/kernel/tracepoint.rs
new file mode 100644
index ..1005f09e0330
--- /dev/null
+++ b/rust/kernel/tracepoint.rs
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2024 Google LLC.
+
+//! Logic for tracepoints.
+
+/// Declare the Rust entry point for a tracepoint.
+#[macro_export]
+macro_rules! declare_trace {
+($($(#[$attr:meta])* $pub:vis fn $name:ident($($argname:ident :
$argtyp:ty),* $(,)?);)*) => {$(
+$( #[$attr] )*
+#[inline(always)]
+$pub unsafe fn $name($($argname : $argtyp),*) {
+#[cfg(CONFIG_TRACEPOINTS)]
+{
+use $crate::bindings::*;
+
+// SAFETY: It's always okay to query the static key for a
