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Date: Thu, 13 Jun 2024 17:03:51 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Bert Karwatzki <spasswolf@web.de>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>, linux-mm@kvack.org,
 linux-kernel@vger.kernel.org, linux-next@vger.kernel.org
Subject: Re: commit 1c29a32ce65f4cd0f1c causes Bad rss-counter state and
 firefox-esr crash in linux-next-20240613
Message-Id: <20240613170351.cc3e7ccfa1bb198b57f31352@linux-foundation.org>
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On Fri, 14 Jun 2024 01:40:54 +0200 Bert Karwatzki <spasswolf@web.de> wrote:

> Since linux-next-20240613 firefox-esr crashes after several minutes of browsing
> giving the following error messages in dmesg:
> [ T2343] BUG: Bad rss-counter state mm:00000000babe0c39 type:MM_ANONPAGES val:86
> [ T4063] show_signal_msg: 16 callbacks suppressed
> [ T4063] Isolated Web Co[4063]: segfault at 396d1686c000 ip 0000396d1686c000 sp
> 00007ffd767b30a8 error 14 likely on CPU 7 (core 3, socket 0)
> [ T4063] Code: Unable to access opcode bytes at 0x396d1686bfd6.
> [ T4211] BUG: Bad rss-counter state mm:00000000cd9fc541 type:MM_ANONPAGES
> val:817
> [ T3798] BUG: Bad rss-counter state mm:00000000432d87c2 type:MM_ANONPAGES
> val:181
> [ T5548] BUG: Bad rss-counter state mm:00000000034aa27a type:MM_ANONPAGES
> val:242
> [ T3823] BUG: Bad rss-counter state mm:0000000099734197 type:MM_ANONPAGES
> val:137
> [    T1] BUG: Bad rss-counter state mm:000000005e5e2f2f type:MM_ANONPAGES val:28

Let's hope Linus doesn't read this.  Why are we nuking the entire
planet just because some counter went wonky?

> (these are the error messages of several crashes and the error seems to affect
> other processes, too (T1))
> 
> The crash can be provoked to appear in ~1min by opening large numbers of tabs in
> firefox-esr (by holding pressing ctrl+t for some time). With this I bisected the
> error to commit "1c29a32ce65f mm/mmap: use split munmap calls for MAP_FIXED" and
> reverting this commit in linux-next-20240613 fixes the issue for me.

Thanks, that must have taken a lot of time.