From: Herbert Xu <herbert@gondor.apana.org.au>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Menglong Dong <dongml2@chinatelecom.cn>,
mhiramat@kernel.org, mathieu.desnoyers@efficios.com,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
oliver.sang@intel.com
Subject: Re: [PATCH] tracing: fprobe: fix suspicious rcu usage in fprobe_entry
Date: Wed, 3 Sep 2025 12:23:46 +0800 [thread overview]
Message-ID: <aLfC0gZS_F3_srMT@gondor.apana.org.au> (raw)
In-Reply-To: <20250902105757.16a78aea@batman.local.home>
On Tue, Sep 02, 2025 at 10:57:57AM -0400, Steven Rostedt wrote:
>
> And then have:
>
> quiet_rcu_read_lock_check();
> head = rhltable_lookup(&fprobe_ip_table, &func, fprobe_rht_params);
> quiet_rcu_read_unlock_check();
The thing is that rhl_for_each_entry_rcu which is called right after
your unlock above should have created the same warning as
rhltable_lookup. The fact that it doesn't appears to be a bug:
it's using rcu_dereference_raw and I don't see why that's safe
at all.
Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
next prev parent reply other threads:[~2025-09-03 4:23 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-29 2:14 Menglong Dong
2025-08-29 2:23 ` Steven Rostedt
2025-08-29 2:49 ` menglong.dong
2025-08-29 11:12 ` Paul E. McKenney
2025-08-29 11:11 ` Paul E. McKenney
2025-09-01 8:06 ` Masami Hiramatsu
2025-09-01 15:00 ` Paul E. McKenney
2025-09-02 6:59 ` Masami Hiramatsu
2025-09-02 11:58 ` Paul E. McKenney
2025-09-03 9:43 ` Herbert Xu
2025-09-04 9:44 ` [PATCH] rhashtable: Use rcu_dereference_all and rcu_dereference_all_check Herbert Xu
2025-09-08 15:23 ` Paul E. McKenney
2025-09-09 9:50 ` [v2 PATCH] " Herbert Xu
2025-09-25 10:17 ` Andrea Righi
2025-09-01 10:06 ` [PATCH] tracing: fprobe: fix suspicious rcu usage in fprobe_entry Herbert Xu
2025-09-01 8:22 ` Masami Hiramatsu
2025-09-02 9:17 ` Herbert Xu
2025-09-02 9:50 ` menglong.dong
2025-09-03 4:22 ` Herbert Xu
2025-09-04 3:37 ` Menglong Dong
2025-09-04 4:29 ` Masami Hiramatsu
2025-09-04 5:42 ` Menglong Dong
2025-09-04 9:08 ` Herbert Xu
2025-09-02 14:57 ` Steven Rostedt
2025-09-03 4:23 ` Herbert Xu [this message]
2025-09-04 5:41 ` menglong.dong
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