Thread (26 messages) 26 messages, 7 authors, 2025-09-25

Re: [PATCH] tracing: fprobe: fix suspicious rcu usage in fprobe_entry

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2025-09-03 04:23:57
Also in: lkml

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 [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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