From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
"David S. Miller" <davem@davemloft.net>,
Ingo Molnar <mingo@redhat.com>, Jakub Kicinski <kuba@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>, Yonghong Song <yhs@fb.com>
Subject: Re: [PATCH net] xdp: xdp_mem_allocator can be NULL in trace_mem_connect().
Date: Thu, 03 Mar 2022 14:59:47 +0100 [thread overview]
Message-ID: <875yovdtm4.fsf@toke.dk> (raw)
In-Reply-To: <YiC0BwndXiwxGDNz@linutronix.de>
Sebastian Andrzej Siewior <bigeasy@linutronix.de> writes:
> Since the commit mentioned below __xdp_reg_mem_model() can return a NULL
> pointer. This pointer is dereferenced in trace_mem_connect() which leads
> to segfault. It can be reproduced with enabled trace events during ifup.
>
> Only assign the arguments in the trace-event macro if `xa' is set.
> Otherwise set the parameters to 0.
>
> Fixes: 4a48ef70b93b8 ("xdp: Allow registering memory model without rxq reference")
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Hmm, so before the commit you mention, the tracepoint wasn't triggered
at all in the code path that now sets xdp_alloc is NULL. So I'm
wondering if we should just do the same here? Is the trace event useful
in all cases?
Alternatively, if we keep it, I think the mem.id and mem.type should be
available from rxq->mem, right?
-Toke
next prev parent reply other threads:[~2022-03-03 13:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-03 12:26 [PATCH net] xdp: xdp_mem_allocator can be NULL in trace_mem_connect() Sebastian Andrzej Siewior
2022-03-03 13:59 ` Toke Høiland-Jørgensen [this message]
2022-03-03 14:12 ` Sebastian Andrzej Siewior
2022-03-03 17:31 ` Jesper Dangaard Brouer
2022-03-07 16:50 ` Toke Høiland-Jørgensen
2022-03-07 17:59 ` Sebastian Andrzej Siewior
2022-03-07 18:07 ` Toke Høiland-Jørgensen
2022-03-09 17:15 ` Jakub Kicinski
2022-03-09 20:48 ` Sebastian Andrzej Siewior
2022-03-09 21:03 ` Jakub Kicinski
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