From: Willem de Bruijn <willemb@google.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Jakub Kicinski <kuba@kernel.org>,
David Miller <davem@davemloft.net>,
Jonathan Lemon <jonathan.lemon@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
"the arch/x86 maintainers" <x86@kernel.org>,
Christoph Hellwig <hch@lst.de>,
Matthew Wilcox <willy@infradead.org>,
Daniel Vetter <daniel@ffwll.ch>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Netdev <netdev@vger.kernel.org>
Subject: Re: [BUG] from x86: Support kmap_local() forced debugging
Date: Thu, 7 Jan 2021 16:07:54 -0500 [thread overview]
Message-ID: <CA+FuTSdsTFHY5Yx8y5UHGYqsz=FGevjYn_Kzy-p3kwx-vUxdDw@mail.gmail.com> (raw)
In-Reply-To: <20210107155256.7af2505e@gandalf.local.home>
On Thu, Jan 7, 2021 at 3:53 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Thu, 7 Jan 2021 11:47:02 -0800
> Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> > On Wed, Jan 6, 2021 at 8:45 PM Willem de Bruijn <willemb@google.com> wrote:
> > >
> > > But there are three other kmap_atomic callers under net/ that do not
> > > loop at all, so assume non-compound pages. In esp_output_head,
> > > esp6_output_head and skb_seq_read. The first two directly use
> > > skb_page_frag_refill, which can allocate compound (but not
> > > __GFP_HIGHMEM) pages, and the third can be inserted with
> > > netfilter xt_string in the path of tcp transmit skbs, which can also
> > > have compound pages. I think that these could similarly access
> > > data beyond the end of the kmap_atomic mapped page. I'll take
> > > a closer look.
> >
> > Thanks.
> >
> > Note that I have flushed my random one-liner patch from my system, and
> > expect to get a proper fix through the normal networking pulls.
> >
> > And _if_ the networking people feel that my one-liner was the proper
> > fix, you can use it and add my sign-off if you want to, but it really
> > was more of a "this is the quick ugly fix for testing" rather than
> > anything else.
I do think it is the proper fix as is. If no one else has comments, I
can submit it through the net tree.
It won't address the other issues that became apparent only as a
result of this. I'm preparing separate patches for those.
> Please add:
>
> Link: https://lore.kernel.org/linux-mm/20210106180132.41dc249d@gandalf.local.home/
> Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>
> And if you take Linus's patch, please add my:
>
> Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>
> and if you come up with another patch, please send it to me for testing.
>
> Thanks!
Will do, thanks.
next prev parent reply other threads:[~2021-01-07 21:08 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-18 19:48 [patch V4 0/8] mm/highmem: Preemptible variant of kmap_atomic & friends Thomas Gleixner
2020-11-18 19:48 ` [patch V4 1/8] mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL Thomas Gleixner
2020-11-18 19:48 ` [patch V4 2/8] mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP Thomas Gleixner
2020-11-18 21:13 ` Linus Torvalds
2020-11-19 8:46 ` Mel Gorman
2020-11-19 17:19 ` Linus Torvalds
2020-11-18 19:48 ` [patch V4 3/8] x86: Support kmap_local() forced debugging Thomas Gleixner
2021-01-06 23:01 ` [BUG] from " Steven Rostedt
2021-01-07 1:03 ` Linus Torvalds
2021-01-07 1:16 ` Steven Rostedt
2021-01-07 1:49 ` Steven Rostedt
2021-01-07 1:49 ` Jakub Kicinski
2021-01-07 2:11 ` Willem de Bruijn
2021-01-07 4:44 ` Willem de Bruijn
2021-01-07 19:47 ` Linus Torvalds
2021-01-07 20:52 ` Steven Rostedt
2021-01-07 21:07 ` Willem de Bruijn [this message]
2020-11-18 19:48 ` [patch V4 4/8] sched: Make migrate_disable/enable() independent of RT Thomas Gleixner
2020-11-19 9:38 ` Mel Gorman
2020-11-19 11:14 ` Peter Zijlstra
2020-11-19 12:14 ` Mel Gorman
2020-11-19 14:17 ` Steven Rostedt
2020-11-19 17:23 ` Linus Torvalds
2020-11-19 18:28 ` Peter Zijlstra
2020-11-20 1:33 ` Thomas Gleixner
2020-11-20 9:29 ` Peter Zijlstra
2020-11-22 23:16 ` Andy Lutomirski
2020-11-23 21:15 ` Thomas Gleixner
2020-11-23 21:25 ` Thomas Gleixner
2020-11-23 22:07 ` Andy Lutomirski
2020-11-23 23:10 ` Thomas Gleixner
2020-11-18 19:48 ` [patch V4 5/8] sched: highmem: Store local kmaps in task struct Thomas Gleixner
2020-11-19 11:33 ` Peter Zijlstra
2020-11-19 11:51 ` Peter Zijlstra
2020-11-19 12:12 ` Peter Zijlstra
2020-11-19 14:11 ` Thomas Gleixner
2020-11-18 19:48 ` [patch V4 6/8] mm/highmem: Provide kmap_local* Thomas Gleixner
2020-11-18 19:48 ` [patch V4 7/8] io-mapping: Provide iomap_local variant Thomas Gleixner
2020-11-18 19:48 ` [patch V4 8/8] x86/crashdump/32: Simplify copy_oldmem_page() Thomas Gleixner
2020-11-24 8:03 ` [patch V4 0/8] mm/highmem: Preemptible variant of kmap_atomic & friends Peter Zijlstra
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