linux-kernel - Re: [PATCH v9 1/5] rust: add generic static_key

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241001174606.6f396dfd@gandalf.local.home>
Date: Tue, 1 Oct 2024 17:46:06 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Josh Poimboeuf <jpoimboe@...nel.org>
Cc: Alice Ryhl <aliceryhl@...gle.com>, Masami Hiramatsu
 <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
 Peter Zijlstra <peterz@...radead.org>, Jason Baron <jbaron@...mai.com>, Ard
 Biesheuvel <ardb@...nel.org>, Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor
 <alex.gaynor@...il.com>, Wedson Almeida Filho <wedsonaf@...il.com>, Boqun
 Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>, Björn Roy Baron <bjorn3_gh@...tonmail.com>, Benno Lossin
 <benno.lossin@...ton.me>, Andreas Hindborg <a.hindborg@...nel.org>,
 linux-trace-kernel@...r.kernel.org, rust-for-linux@...r.kernel.org,
 linux-kernel@...r.kernel.org, Arnd Bergmann <arnd@...db.de>,
 linux-arch@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>, Ingo
 Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, Dave Hansen
 <dave.hansen@...ux.intel.com>, x86@...nel.org, "H. Peter Anvin"
 <hpa@...or.com>, Sean Christopherson <seanjc@...gle.com>, Uros Bizjak
 <ubizjak@...il.com>, Catalin Marinas <catalin.marinas@....com>, Will Deacon
 <will@...nel.org>, Marc Zyngier <maz@...nel.org>, Oliver Upton
 <oliver.upton@...ux.dev>, Mark Rutland <mark.rutland@....com>, Ryan Roberts
 <ryan.roberts@....com>, Fuad Tabba <tabba@...gle.com>,
 linux-arm-kernel@...ts.infradead.org, Paul Walmsley
 <paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, Albert Ou
 <aou@...s.berkeley.edu>, Anup Patel <apatel@...tanamicro.com>, Andrew Jones
 <ajones@...tanamicro.com>, Alexandre Ghiti <alexghiti@...osinc.com>, Conor
 Dooley <conor.dooley@...rochip.com>, Samuel Holland
 <samuel.holland@...ive.com>, linux-riscv@...ts.infradead.org, Huacai Chen
 <chenhuacai@...nel.org>, WANG Xuerui <kernel@...0n.name>, Bibo Mao
 <maobibo@...ngson.cn>, Tiezhu Yang <yangtiezhu@...ngson.cn>, Andrew Morton
 <akpm@...ux-foundation.org>, Tianrui Zhao <zhaotianrui@...ngson.cn>,
 loongarch@...ts.linux.dev
Subject: Re: [PATCH v9 1/5] rust: add generic static_key_false

On Tue, 1 Oct 2024 14:15:43 -0700
Josh Poimboeuf <jpoimboe@...nel.org> wrote:

> On Tue, Oct 01, 2024 at 01:29:58PM +0000, Alice Ryhl wrote:
> > Add just enough support for static key so that we can use it from
> > tracepoints. Tracepoints rely on `static_key_false` even though it is
> > deprecated, so we add the same functionality to Rust.  
> 
> Instead of extending the old deprecated static key interface into Rust,
> can we just change tracepoints to use the new one?

Sure, care to send the patch properly, and I can add it to my queue.

-- Steve

> 
> /me makes a note to go convert the other users...
> 
> From: Josh Poimboeuf <jpoimboe@...nel.org>
> Subject: [PATCH] tracepoints: Use new static branch API
> 
> The old static key API based on 'struct static_key' is deprecated.
> Convert tracepoints to use the new API.
> 
> Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
> ---
>  include/linux/tracepoint-defs.h | 4 ++--
>  include/linux/tracepoint.h      | 8 ++++----
>  kernel/tracepoint.c             | 4 ++--
>  3 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h
> index 4dc4955f0fbf..60a6e8314d4c 100644
> --- a/include/linux/tracepoint-defs.h
> +++ b/include/linux/tracepoint-defs.h
> @@ -31,7 +31,7 @@ struct tracepoint_func {
>  
>  struct tracepoint {
>  	const char *name;		/* Tracepoint name */
> -	struct static_key key;
> +	struct static_key_false key;
>  	struct static_call_key *static_call_key;
>  	void *static_call_tramp;
>  	void *iterator;
> @@ -83,7 +83,7 @@ struct bpf_raw_event_map {
>  
>  #ifdef CONFIG_TRACEPOINTS
>  # define tracepoint_enabled(tp) \
> -	static_key_false(&(__tracepoint_##tp).key)
> +	static_branch_unlikely(&(__tracepoint_##tp).key)
>  #else
>  # define tracepoint_enabled(tracepoint) false
>  #endif
> diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> index 6be396bb4297..ab5162fc3e4a 100644
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -228,7 +228,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
>  #define __DECLARE_TRACE_RCU(name, proto, args, cond)			\
>  	static inline void trace_##name##_rcuidle(proto)		\
>  	{								\
> -		if (static_key_false(&__tracepoint_##name.key))		\
> +		if (static_branch_unlikely(&__tracepoint_##name.key))	\
>  			__DO_TRACE(name,				\
>  				TP_ARGS(args),				\
>  				TP_CONDITION(cond), 1);			\
> @@ -254,7 +254,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
>  	extern struct tracepoint __tracepoint_##name;			\
>  	static inline void trace_##name(proto)				\
>  	{								\
> -		if (static_key_false(&__tracepoint_##name.key))		\
> +		if (static_branch_unlikely(&__tracepoint_##name.key))	\
>  			__DO_TRACE(name,				\
>  				TP_ARGS(args),				\
>  				TP_CONDITION(cond), 0);			\
> @@ -291,7 +291,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
>  	static inline bool						\
>  	trace_##name##_enabled(void)					\
>  	{								\
> -		return static_key_false(&__tracepoint_##name.key);	\
> +		return static_branch_unlikely(&__tracepoint_##name.key);\
>  	}
>  
>  /*
> @@ -308,7 +308,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
>  	struct tracepoint __tracepoint_##_name	__used			\
>  	__section("__tracepoints") = {					\
>  		.name = __tpstrtab_##_name,				\
> -		.key = STATIC_KEY_INIT_FALSE,				\
> +		.key = STATIC_KEY_FALSE_INIT,				\
>  		.static_call_key = &STATIC_CALL_KEY(tp_func_##_name),	\
>  		.static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
>  		.iterator = &__traceiter_##_name,			\
> diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
> index 8d1507dd0724..dc160cc0b616 100644
> --- a/kernel/tracepoint.c
> +++ b/kernel/tracepoint.c
> @@ -358,7 +358,7 @@ static int tracepoint_add_func(struct tracepoint *tp,
>  		tracepoint_update_call(tp, tp_funcs);
>  		/* Both iterator and static call handle NULL tp->funcs */
>  		rcu_assign_pointer(tp->funcs, tp_funcs);
> -		static_key_enable(&tp->key);
> +		static_branch_enable(&tp->key);
>  		break;
>  	case TP_FUNC_2:		/* 1->2 */
>  		/* Set iterator static call */
> @@ -414,7 +414,7 @@ static int tracepoint_remove_func(struct tracepoint *tp,
>  		if (tp->unregfunc && static_key_enabled(&tp->key))
>  			tp->unregfunc();
>  
> -		static_key_disable(&tp->key);
> +		static_branch_disable(&tp->key);
>  		/* Set iterator static call */
>  		tracepoint_update_call(tp, tp_funcs);
>  		/* Both iterator and static call handle NULL tp->funcs */