From: Catalin Marinas <catalin.marinas@arm.com>
To: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Will Deacon <will@kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH 3/3] btrfs: Avoid live-lock in search_ioctl() on hardware with sub-page faults
Date: Mon, 29 Nov 2021 13:52:12 +0000 [thread overview]
Message-ID: <YaTbDJS5MtvIm9aS@arm.com> (raw)
In-Reply-To: <CAHc6FU7BSL58GVkOh=nsNQczRKG3P+Ty044zs7PjKPik4vzz=Q@mail.gmail.com>
On Sat, Nov 27, 2021 at 07:05:39PM +0100, Andreas Gruenbacher wrote:
> Maybe you want to add this though:
>
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -2202,3 +2202,3 @@ static noinline int search_ioctl(struct inode *inode,
> unsigned long sk_offset = 0;
> - char __user *fault_in_addr;
> + char __user *fault_in_addr, *end;
>
> @@ -2230,6 +2230,6 @@ static noinline int search_ioctl(struct inode *inode,
> fault_in_addr = ubuf;
> + end = ubuf + *buf_size;
> while (1) {
> ret = -EFAULT;
> - if (fault_in_writeable(fault_in_addr,
> - *buf_size - (fault_in_addr - ubuf)))
> + if (fault_in_writeable(fault_in_addr, end - fault_in_addr))
> break;
It looks like *buf_size is updated inside copy_to_sk(), so I'll move the
end update inside the loop.
--
Catalin
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next prev parent reply other threads:[~2021-11-29 13:53 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-24 19:20 [PATCH 0/3] Avoid live-lock in fault-in+uaccess loops with sub-page faults Catalin Marinas
2021-11-24 19:20 ` [PATCH 1/3] mm: Introduce fault_in_exact_writeable() to probe for " Catalin Marinas
2021-11-24 19:20 ` [PATCH 2/3] arm64: Add support for sub-page faults user probing Catalin Marinas
2021-11-24 19:20 ` [PATCH 3/3] btrfs: Avoid live-lock in search_ioctl() on hardware with sub-page faults Catalin Marinas
2021-11-24 20:03 ` Matthew Wilcox
2021-11-24 20:37 ` Catalin Marinas
2021-11-25 22:25 ` Andreas Gruenbacher
2021-11-25 22:42 ` Catalin Marinas
2021-11-26 22:29 ` Andreas Gruenbacher
2021-11-26 22:57 ` Catalin Marinas
2021-11-27 3:52 ` Andreas Gruenbacher
2021-11-27 14:33 ` Catalin Marinas
2021-11-27 12:39 ` Andreas Gruenbacher
2021-11-27 15:21 ` Catalin Marinas
2021-11-27 18:05 ` Andreas Gruenbacher
2021-11-29 12:16 ` Catalin Marinas
2021-11-29 13:33 ` Andreas Gruenbacher
2021-11-29 15:36 ` Catalin Marinas
2021-11-29 18:40 ` Linus Torvalds
2021-11-29 19:31 ` Andreas Gruenbacher
2021-11-29 20:56 ` Catalin Marinas
2021-11-29 21:53 ` Linus Torvalds
2021-11-29 23:12 ` Catalin Marinas
2021-11-29 13:52 ` Catalin Marinas [this message]
2021-11-24 23:00 ` Linus Torvalds
2021-11-25 11:10 ` Catalin Marinas
2021-11-25 18:13 ` Linus Torvalds
2021-11-25 20:43 ` Catalin Marinas
2021-11-25 21:02 ` Matthew Wilcox
2021-11-25 21:29 ` Catalin Marinas
2021-11-25 21:40 ` Andreas Gruenbacher
2021-11-26 16:42 ` David Sterba
2021-11-24 21:36 ` [PATCH 0/3] Avoid live-lock in fault-in+uaccess loops " Andrew Morton
2021-11-24 22:31 ` Catalin Marinas
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