Go to file
Mark Rutland 564cbc8793 locking/atomics, selftests/powerpc: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE()
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't currently harmful.

However, for some features it is necessary to instrument reads and
writes separately, which is not possible with ACCESS_ONCE(). This
distinction is critical to correct operation.

The bulk of the kernel code can be transformed via Coccinelle to use
{READ,WRITE}_ONCE(), though this only modifies users of ACCESS_ONCE(),
and not the implementation itself. As such, it has the potential to
break homebrew ACCESS_ONCE() macros seen in some user code in the kernel
tree (e.g. the virtio code, as fixed in commit ea9156fb3b).

To avoid fragility if/when that transformation occurs, and to align with
the preferred usage of {READ,WRITE}_ONCE(), this patch updates the DSCR
selftest code to use READ_ONCE() rather than ACCESS_ONCE(). There should
be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-11-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:02 +02:00
arch locking/qrwlock, arm64: Move rwlock implementation over to qrwlocks 2017-10-25 10:57:25 +02:00
block bio_copy_user_iov(): don't ignore ->iov_offset 2017-10-10 23:55:14 -04:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto Merge commit 'tags/keys-fixes-20171018' into fixes-v4.14-rc5 2017-10-19 12:28:38 +11:00
Documentation locking/barriers: Kill lockless_dereference() 2017-10-24 13:17:33 +02:00
drivers locking/atomics, media/dvb_ringbuffer: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:00:58 +02:00
firmware firmware: Restore support for built-in firmware 2017-09-16 10:58:48 -07:00
fs locking/atomics, fs/ncpfs: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:00:58 +02:00
include locking/atomics, net/average: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:00 +02:00
init Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:54:01 -07:00
ipc fix a typo in put_compat_shm_info() 2017-09-25 20:41:46 -04:00
kernel locking/qrwlock: Prevent slowpath writers getting held up by fastpath 2017-10-25 10:57:25 +02:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-21 22:44:48 -04:00
mm locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-10-24 13:17:33 +02:00
net locking/atomics, net/ipv4/tcp_input.c: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:00 +02:00
samples locking/atomics, samples/mic/mpssd/mpssd.c: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:01 +02:00
scripts linux/compiler.h: Split into compiler.h and compiler_types.h 2017-10-24 13:17:32 +02:00
security Linux 4.14-rc6 2017-10-24 13:17:20 +02:00
sound ALSA: hda - Fix incorrect TLV callback check introduced during set_fs() removal 2017-10-18 12:27:00 +02:00
tools locking/atomics, selftests/powerpc: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:02 +02:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt Revert "KVM: Don't accept obviously wrong gsi values via KVM_IRQFD" 2017-09-19 08:37:17 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap Update James Hogan's email address 2017-10-04 17:11:53 -07:00
COPYING
CREDITS selinux/stable-4.14 PR 20170831 2017-09-12 13:21:00 -07:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS USB/PHY fixes for 4.14-rc6 2017-10-23 06:33:05 -04:00
Makefile Linux 4.14-rc6 2017-10-23 06:49:47 -04:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.