From: Nam Cao <namcao@linutronix.de>
To: Andreas Dilger <adilger@dilger.ca>
Cc: "Mike Rapoport" <rppt@kernel.org>,
"Matthew Wilcox" <willy@infradead.org>,
"Björn Töpel" <bjorn@kernel.org>,
"Christian Brauner" <brauner@kernel.org>,
"Al Viro" <viro@zeniv.linux.org.uk>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
"Jan Kara" <jack@suse.cz>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-riscv@lists.infradead.org, "Theodore Ts'o" <tytso@mit.edu>,
"Ext4 Developers List" <linux-ext4@vger.kernel.org>,
"Conor Dooley" <conor@kernel.org>,
"Anders Roxell" <anders.roxell@linaro.org>,
"Alexandre Ghiti" <alex@ghiti.fr>
Subject: Re: riscv32 EXT4 splat, 6.8 regression?
Date: Thu, 18 Apr 2024 11:17:53 +0200 [thread overview]
Message-ID: <20240418111753.1c485974@namcao> (raw)
In-Reply-To: <1F07FFF3-663B-43D4-A9DA-C89856F2962A@dilger.ca>
On 2024-04-17 Andreas Dilger wrote:
> On Apr 16, 2024, at 4:36 PM, Nam Cao <namcao@linutronix.de> wrote:
> > However, I am confused about one thing: doesn't this make one page of
> > physical memory inaccessible?
> >
> > Is it better to solve this by setting max_low_pfn instead? Then at
> > least the page is still accessible as high memory.
>
> Is that one page of memory really worthwhile to preserve? Better to
> have a simple solution that works,
Good point.
> maybe even mapping that page
> read-only so that any code which tries to dereference an ERR_PTR
> address immediately gets a fault?
Not sure about this part: it doesn't really fix the problem, just
changes from subtle crashes into page faults.
Let me send a patch to reserve the page: simple and works for all
architectures.
Best regards,
Nam
WARNING: multiple messages have this Message-ID (diff)
From: Nam Cao <namcao@linutronix.de>
To: Andreas Dilger <adilger@dilger.ca>
Cc: "Mike Rapoport" <rppt@kernel.org>,
"Matthew Wilcox" <willy@infradead.org>,
"Björn Töpel" <bjorn@kernel.org>,
"Christian Brauner" <brauner@kernel.org>,
"Al Viro" <viro@zeniv.linux.org.uk>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
"Jan Kara" <jack@suse.cz>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-riscv@lists.infradead.org, "Theodore Ts'o" <tytso@mit.edu>,
"Ext4 Developers List" <linux-ext4@vger.kernel.org>,
"Conor Dooley" <conor@kernel.org>,
"Anders Roxell" <anders.roxell@linaro.org>,
"Alexandre Ghiti" <alex@ghiti.fr>
Subject: Re: riscv32 EXT4 splat, 6.8 regression?
Date: Thu, 18 Apr 2024 11:17:53 +0200 [thread overview]
Message-ID: <20240418111753.1c485974@namcao> (raw)
In-Reply-To: <1F07FFF3-663B-43D4-A9DA-C89856F2962A@dilger.ca>
On 2024-04-17 Andreas Dilger wrote:
> On Apr 16, 2024, at 4:36 PM, Nam Cao <namcao@linutronix.de> wrote:
> > However, I am confused about one thing: doesn't this make one page of
> > physical memory inaccessible?
> >
> > Is it better to solve this by setting max_low_pfn instead? Then at
> > least the page is still accessible as high memory.
>
> Is that one page of memory really worthwhile to preserve? Better to
> have a simple solution that works,
Good point.
> maybe even mapping that page
> read-only so that any code which tries to dereference an ERR_PTR
> address immediately gets a fault?
Not sure about this part: it doesn't really fix the problem, just
changes from subtle crashes into page faults.
Let me send a patch to reserve the page: simple and works for all
architectures.
Best regards,
Nam
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linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2024-04-18 9:17 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-12 14:57 riscv32 EXT4 splat, 6.8 regression? Björn Töpel
2024-04-12 14:57 ` Björn Töpel
2024-04-12 15:43 ` Theodore Ts'o
2024-04-12 15:43 ` Theodore Ts'o
2024-04-12 16:59 ` Björn Töpel
2024-04-12 16:59 ` Björn Töpel
2024-04-13 4:35 ` Theodore Ts'o
2024-04-13 4:35 ` Theodore Ts'o
2024-04-13 10:01 ` Conor Dooley
2024-04-13 10:01 ` Conor Dooley
2024-04-13 14:43 ` Nam Cao
2024-04-13 14:43 ` Nam Cao
2024-04-14 0:24 ` Theodore Ts'o
2024-04-14 0:24 ` Theodore Ts'o
2024-04-14 1:46 ` Andreas Dilger
2024-04-14 1:46 ` Andreas Dilger
2024-04-14 2:04 ` Theodore Ts'o
2024-04-14 2:04 ` Theodore Ts'o
2024-04-14 2:18 ` Al Viro
2024-04-14 2:18 ` Al Viro
2024-04-14 2:15 ` Al Viro
2024-04-14 2:15 ` Al Viro
2024-04-14 4:16 ` Andreas Dilger
2024-04-14 4:16 ` Andreas Dilger
2024-04-14 14:08 ` Björn Töpel
2024-04-14 14:08 ` Björn Töpel
2024-04-15 13:04 ` Christian Brauner
2024-04-15 13:04 ` Christian Brauner
2024-04-15 16:04 ` Björn Töpel
2024-04-15 16:04 ` Björn Töpel
2024-04-16 6:44 ` Nam Cao
2024-04-16 6:44 ` Nam Cao
2024-04-16 8:25 ` Christian Brauner
2024-04-16 8:25 ` Christian Brauner
2024-04-16 11:02 ` Björn Töpel
2024-04-16 11:02 ` Björn Töpel
2024-04-16 14:24 ` Mike Rapoport
2024-04-16 14:24 ` Mike Rapoport
2024-04-16 15:17 ` Nam Cao
2024-04-16 15:17 ` Nam Cao
2024-04-16 15:30 ` Nam Cao
2024-04-16 15:30 ` Nam Cao
2024-04-16 15:56 ` Björn Töpel
2024-04-16 15:56 ` Björn Töpel
2024-04-16 16:19 ` Nam Cao
2024-04-16 16:19 ` Nam Cao
2024-04-16 16:31 ` Mike Rapoport
2024-04-16 16:31 ` Mike Rapoport
2024-04-16 17:00 ` Matthew Wilcox
2024-04-16 17:00 ` Matthew Wilcox
2024-04-16 18:34 ` Mike Rapoport
2024-04-16 18:34 ` Mike Rapoport
2024-04-16 22:36 ` Nam Cao
2024-04-16 22:36 ` Nam Cao
2024-04-17 15:31 ` Theodore Ts'o
2024-04-17 15:31 ` Theodore Ts'o
2024-04-17 18:06 ` Nam Cao
2024-04-17 18:06 ` Nam Cao
2024-04-17 19:34 ` Mike Rapoport
2024-04-17 19:34 ` Mike Rapoport
2024-04-17 22:09 ` Andreas Dilger
2024-04-17 22:09 ` Andreas Dilger
2024-04-18 9:17 ` Nam Cao [this message]
2024-04-18 9:17 ` Nam Cao
2024-04-16 18:05 ` Björn Töpel
2024-04-16 18:05 ` Björn Töpel
2024-04-16 18:09 ` Nam Cao
2024-04-16 18:09 ` Nam Cao
2024-04-16 16:19 ` Mike Rapoport
2024-04-16 16:19 ` Mike Rapoport
2024-04-16 16:31 ` Matthew Wilcox
2024-04-16 16:31 ` Matthew Wilcox
2024-04-16 18:18 ` Mike Rapoport
2024-04-16 18:18 ` Mike Rapoport
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