From: Tejun Heo <tj@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
netdev@vger.kernel.org, syzkaller@googlegroups.com,
Daniel Borkmann <daniel@iogearbox.net>,
"David S. Miller" <davem@davemloft.net>,
Alexei Starovoitov <ast@kernel.org>,
Christoph Lameter <cl@linux.com>
Subject: Re: EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2
Date: Thu, 28 Sep 2017 07:52:11 -0700 [thread overview]
Message-ID: <20170928145211.GD15129@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <20170928112727.GA11310@leverpostej>
Hello,
On Thu, Sep 28, 2017 at 12:27:28PM +0100, Mark Rutland wrote:
> diff --git a/mm/percpu.c b/mm/percpu.c
> index 59d44d6..f731c45 100644
> --- a/mm/percpu.c
> +++ b/mm/percpu.c
> @@ -1355,8 +1355,13 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,
> bits = size >> PCPU_MIN_ALLOC_SHIFT;
> bit_align = align >> PCPU_MIN_ALLOC_SHIFT;
>
> - if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE ||
> - !is_power_of_2(align))) {
> + if (unlikely(size > PCPU_MIN_UNIT_SIZE)) {
> + pr_warn("cannot allocate pcpu chunk of size %zu (max %zu)\n",
> + size, PCPU_MIN_UNIT_SIZE);
WARN_ONCE() probably is the better choice here. We wanna know who
tries to allocate larger than the supported size and increase the size
limit if warranted.
Thanks.
--
tejun
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prev parent reply other threads:[~2017-09-28 14:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-28 11:27 EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2 Mark Rutland
2017-09-28 14:37 ` Daniel Borkmann
2017-09-28 14:45 ` Mark Rutland
2017-09-28 14:53 ` Tejun Heo
2017-09-28 15:00 ` Daniel Borkmann
2017-09-28 14:52 ` Tejun Heo [this message]
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