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From: Daniel Borkmann <daniel@iogearbox.net>
To: Alexei Starovoitov <ast@kernel.org>, davem@davemloft.net
Cc: jannh@google.com, paulmck@kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH bpf-next] bpf: Fix trampoline usage in preempt
Date: Wed, 22 Jan 2020 16:55:34 +0100	[thread overview]
Message-ID: <1ab7d6f3-fc97-cb29-cf77-7d0d9b70e9ca@iogearbox.net> (raw)
In-Reply-To: <20200121032231.3292185-1-ast@kernel.org>

On 1/21/20 4:22 AM, Alexei Starovoitov wrote:
> Though the second half of trampoline page is unused a task could be
> preempted in the middle of the first half of trampoline and two
> updates to trampoline would change the code from underneath the
> preempted task. Hence wait for tasks to voluntarily schedule or go
> to userspace.
> Add similar wait before freeing the trampoline.
> 
> Fixes: fec56f5890d9 ("bpf: Introduce BPF trampoline")
> Reported-by: Jann Horn <jannh@google.com>
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Applied, thanks!

      parent reply	other threads:[~2020-01-22 15:55 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-21  3:22 [PATCH bpf-next] bpf: Fix trampoline usage in preempt Alexei Starovoitov
2020-01-21  4:54 ` Paul E. McKenney
2020-01-22 15:55 ` Daniel Borkmann [this message]

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