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
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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