From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH] Convert filldir[64]() from __put_user() to unsafe_put_user()
Date: Tue, 8 Oct 2019 21:34:51 +0100 [thread overview]
Message-ID: <20191008203451.GX26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20191008195858.GV26530@ZenIV.linux.org.uk>
On Tue, Oct 08, 2019 at 08:58:58PM +0100, Al Viro wrote:
> The difference is, they have separate "for read" and "for write" primitives
> and they want the range in their user_access_end() analogue. Separating
> the read and write isn't a problem for callers (we want them close to
> the actual memory accesses). Passing the range to user_access_end() just
> might be tolerable, unless it makes you throw up...
NOTE: I'm *NOT* suggesting to bring back the VERIFY_READ/VERIFY_WRITE
argument to access_ok(). We'd gotten rid of it, and for a very good
reason (and decades overdue).
The main difference between access_ok() and user_access_begin() is that
the latter is right next to actual memory access, with user_access_end()
on the other side, also very close. And most of those guys would be
concentrated in a few functions, where we bloody well know which
direction we are copying.
Even if we try and map ppc allow_..._to_user() on user_access_begin(),
access_ok() remains as it is (and I hope we'll get rid of the majority
of its caller in process).
next prev parent reply other threads:[~2019-10-08 20:34 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-06 22:20 [PATCH] Convert filldir[64]() from __put_user() to unsafe_put_user() Guenter Roeck
2019-10-06 23:06 ` Linus Torvalds
2019-10-06 23:35 ` Linus Torvalds
2019-10-07 0:04 ` Guenter Roeck
2019-10-07 1:17 ` Linus Torvalds
2019-10-07 1:24 ` Al Viro
2019-10-07 2:06 ` Linus Torvalds
2019-10-07 2:50 ` Al Viro
2019-10-07 3:11 ` Linus Torvalds
2019-10-07 15:40 ` David Laight
2019-10-07 18:11 ` Linus Torvalds
2019-10-08 9:58 ` David Laight
2019-10-07 17:34 ` Al Viro
2019-10-07 18:13 ` Linus Torvalds
2019-10-07 18:22 ` Al Viro
2019-10-07 18:26 ` Linus Torvalds
2019-10-07 18:36 ` Tony Luck
2019-10-07 19:08 ` Linus Torvalds
2019-10-07 19:49 ` Tony Luck
2019-10-07 20:04 ` Linus Torvalds
2019-10-08 3:29 ` Al Viro
2019-10-08 4:09 ` Linus Torvalds
2019-10-08 4:14 ` Linus Torvalds
2019-10-08 5:02 ` Al Viro
2019-10-08 4:24 ` Linus Torvalds
2019-10-10 19:55 ` Al Viro
2019-10-10 22:12 ` Linus Torvalds
2019-10-11 0:11 ` Al Viro
2019-10-11 0:31 ` Linus Torvalds
2019-10-13 18:13 ` Al Viro
2019-10-13 18:43 ` Linus Torvalds
2019-10-13 19:10 ` Al Viro
2019-10-13 19:22 ` Linus Torvalds
2019-10-13 19:59 ` Al Viro
2019-10-13 20:20 ` Linus Torvalds
2019-10-15 3:46 ` Michael Ellerman
2019-10-15 18:08 ` Al Viro
2019-10-15 19:00 ` Linus Torvalds
2019-10-15 19:40 ` Al Viro
2019-10-15 20:18 ` Al Viro
2019-10-16 12:12 ` [RFC] change of calling conventions for arch_futex_atomic_op_inuser() Al Viro
2019-10-16 12:24 ` Thomas Gleixner
2019-10-16 20:25 ` [PATCH] Convert filldir[64]() from __put_user() to unsafe_put_user() Al Viro
2019-10-17 19:36 ` [RFC][PATCHES] drivers/scsi/sg.c uaccess cleanups/fixes Al Viro
2019-10-17 19:39 ` [RFC PATCH 1/8] sg_ioctl(): fix copyout handling Al Viro
2019-10-17 19:39 ` [RFC PATCH 2/8] sg_new_write(): replace access_ok() + __copy_from_user() with copy_from_user() Al Viro
2019-10-17 19:39 ` [RFC PATCH 3/8] sg_write(): __get_user() can fail Al Viro
2019-10-17 19:39 ` [RFC PATCH 4/8] sg_read(): simplify reading ->pack_id of userland sg_io_hdr_t Al Viro
2019-10-17 19:39 ` [RFC PATCH 5/8] sg_new_write(): don't bother with access_ok Al Viro
2019-10-17 19:39 ` [RFC PATCH 6/8] sg_read(): get rid of access_ok()/__copy_..._user() Al Viro
2019-10-17 19:39 ` [RFC PATCH 7/8] sg_write(): get rid of access_ok()/__copy_from_user()/__get_user() Al Viro
2019-10-17 19:39 ` [RFC PATCH 8/8] SG_IO: get rid of access_ok() Al Viro
2019-10-17 21:44 ` [RFC][PATCHES] drivers/scsi/sg.c uaccess cleanups/fixes Douglas Gilbert
2019-11-05 4:54 ` Martin K. Petersen
2019-11-05 5:25 ` Al Viro
2019-11-06 4:29 ` Martin K. Petersen
2019-10-18 0:27 ` [RFC] csum_and_copy_from_user() semantics Al Viro
2019-10-25 14:01 ` [PATCH] Convert filldir[64]() from __put_user() to unsafe_put_user() Thomas Gleixner
2019-10-08 4:57 ` Al Viro
2019-10-08 13:14 ` Greg KH
2019-10-08 15:29 ` Al Viro
2019-10-08 15:38 ` Greg KH
2019-10-08 17:06 ` Al Viro
2019-10-08 19:58 ` Al Viro
2019-10-08 20:16 ` Al Viro
2019-10-08 20:34 ` Al Viro [this message]
2019-10-07 2:30 ` Guenter Roeck
2019-10-07 3:12 ` Linus Torvalds
2019-10-07 0:23 ` Guenter Roeck
2019-10-07 4:04 ` Max Filippov
2019-10-07 12:16 ` Guenter Roeck
2019-10-07 19:21 ` Linus Torvalds
2019-10-07 20:29 ` Guenter Roeck
2019-10-07 23:27 ` Guenter Roeck
2019-10-08 6:28 ` Geert Uytterhoeven
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=20191008203451.GX26530@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@roeck-us.net \
--cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.