netdev - Re: [RFC PATCH 1/4] splice: Fix corruption of spliced data after splice() returns

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 24 Jul 2023 15:55:21 +0200
From: Miklos Szeredi <miklos@...redi.hu>
To: David Howells <dhowells@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>, Matthew Wilcox <willy@...radead.org>, 
	Matt Whitlock <kernel@...twhitlock.name>, netdev@...r.kernel.org, 
	Dave Chinner <david@...morbit.com>, Jens Axboe <axboe@...nel.dk>, linux-fsdevel@...ck.org, 
	linux-mm@...ck.org, linux-kernel@...r.kernel.org, 
	Christoph Hellwig <hch@....de>, linux-fsdevel@...r.kernel.org
Subject: Re: [RFC PATCH 1/4] splice: Fix corruption of spliced data after
 splice() returns

On Mon, 24 Jul 2023 at 11:44, David Howells <dhowells@...hat.com> wrote:
>
> Linus Torvalds <torvalds@...ux-foundation.org> wrote:
>
> > > So what's the API that provides the semantics of _copying_?
> >
> > It's called "read()" and "write()".
>
> What about copy_file_range()?  That seems to fall back to splicing if not
> directly implemented by the filesystem.  It looks like the manpage for that
> needs updating too - or should that actually copy?

Both source and destination of copy_file_range() are regular files and
do_splice_direct() is basically equivalent to write(dest, mmap of
source), no refd buffers remain beyond the end of the syscall.  What
is it that should be updated in the manpage?

Thanks,
Miklos