linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Chen Huang <chenhuang5@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Randy Dunlap <rdunlap@infradead.org>,
	"Catalin Marinas" <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-mm <linux-mm@kvack.org>,
	"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] arm64: an infinite loop in generic_perform_write()
Date: Thu, 24 Jun 2021 11:52:53 +0800	[thread overview]
Message-ID: <e5730b44-6aae-c486-8495-d170fdf9baa1@huawei.com> (raw)
In-Reply-To: <YNP6/p/yJzLLr8M8@casper.infradead.org>



在 2021/6/24 11:24, Matthew Wilcox 写道:
> On Thu, Jun 24, 2021 at 11:10:41AM +0800, Chen Huang wrote:
>> In userspace, I perform such operation:
>>
>>  	fd = open("/tmp/test", O_RDWR | O_SYNC);
>>         access_address = (char *)mmap(NULL, uio_size, PROT_READ, MAP_SHARED, uio_fd, 0);
>>         ret = write(fd, access_address + 2, sizeof(long));
> 
> ... you know that accessing this at unaligned offsets isn't going to
> work.  It's completely meaningless.  Why are you trying to do it?
> .
> 

Yeah, it's a wrong usage of access. But maybe it's still a problem
an userspace operation  makes the kernel crash.


  reply	other threads:[~2021-06-24  3:53 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-23  2:39 Chen Huang
2021-06-23  2:50 ` Al Viro
2021-06-23  3:24   ` Xiaoming Ni
2021-06-23  4:27     ` Al Viro
2021-06-23  9:32       ` Catalin Marinas
2021-06-23 11:51         ` Matthew Wilcox
2021-06-23 13:04         ` Al Viro
2021-06-23 13:22 ` Mark Rutland
2021-06-24  3:10   ` Chen Huang
2021-06-24  3:24     ` Matthew Wilcox
2021-06-24  3:52       ` Chen Huang [this message]
2021-06-24  7:04       ` Christoph Hellwig
2021-06-24 11:15         ` Matthew Wilcox
2021-06-24 13:22           ` Robin Murphy
2021-06-24 16:27             ` Al Viro
2021-06-24 16:38               ` Robin Murphy
2021-06-24 16:39                 ` Al Viro
2021-06-24 17:24                   ` Robin Murphy
2021-06-24 18:55               ` Catalin Marinas
2021-06-24 20:36                 ` Robin Murphy
2021-06-25 10:39                   ` Catalin Marinas
2021-06-28 16:22                     ` Robin Murphy
2021-06-29  8:30                       ` Catalin Marinas
2021-06-29 10:01                         ` Robin Murphy
2021-07-06 17:50                       ` Catalin Marinas
2021-07-06 19:15                         ` Robin Murphy
2021-07-07  9:55                           ` David Laight
2021-07-07 11:04                             ` Robin Murphy
2021-07-07 12:50                           ` Catalin Marinas
2021-06-24 15:09           ` Catalin Marinas
2021-06-24 16:17             ` Al Viro

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=e5730b44-6aae-c486-8495-d170fdf9baa1@huawei.com \
    --to=chenhuang5@huawei.com \
    --cc=akpm@linux-foundation.org \
    --cc=catalin.marinas@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mark.rutland@arm.com \
    --cc=rdunlap@infradead.org \
    --cc=sfr@canb.auug.org.au \
    --cc=viro@zeniv.linux.org.uk \
    --cc=will@kernel.org \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox