From: Nick Alcock <nix@esperi.org.uk>
To: Kris Van Hees <kris.van.hees@oracle.com>
Cc: dtrace@lists.linux.dev, dtrace-devel@oss.oracle.com
Subject: Re: [PATCH 5/6] fbt: retrieve function return value using helper
Date: Tue, 28 Apr 2026 21:52:04 +0100 [thread overview]
Message-ID: <87jytqreob.fsf@esperi.org.uk> (raw)
In-Reply-To: <3dc679a2ee099ae4e555e093422b17b6@oracle.com> (Kris Van Hees's message of "Tue, 28 Apr 2026 19:05:27 +0000")
On 28 Apr 2026, Kris Van Hees outgrape:
> We were causing BPF verifier errors when trying to access the return value
> of some functions due to incorrect calculation of the offset to read from.
> Rather than implementing the more complex logic needed to calculate the
> proper offset of the return value, we can just use the bpf_get_func_ret()
> BPF helper. This does not impose a performance decrease because that
> helper gets inlined by the BPF verifier.
Presumably we are a suitable probe type? ... yes, we are.
> Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
Looks much nicer.
--
NULL && (void)
prev parent reply other threads:[~2026-04-28 20:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-28 19:05 [PATCH 5/6] fbt: retrieve function return value using helper Kris Van Hees
2026-04-28 20:52 ` Nick Alcock [this message]
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