[tip:sched/core] sched/wait: Change wait_on_bit*() to take an unsigned long *, not a void *

From: tip-bot for Palmer Dabbelt
Date: Fri May 08 2015 - 09:21:59 EST


Commit-ID: 7e60598785f30cf3dc9e476cc0fc3feeb37a0c63
Gitweb: http://git.kernel.org/tip/7e60598785f30cf3dc9e476cc0fc3feeb37a0c63
Author: Palmer Dabbelt <palmer@xxxxxxxxxxx>
AuthorDate: Thu, 30 Apr 2015 21:19:56 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 8 May 2015 12:05:41 +0200

sched/wait: Change wait_on_bit*() to take an unsigned long *, not a void *

The implementations of wait_on_bit*() will only work with long-aligned
memory on systems that don't support misaligned loads and stores.

This patch changes the function prototypes to ensure that the compiler
will enforce alignment.

Running

make defconfig
make KFLAGS="-Werror"

seems to indicate that, as of c56fb6564dcd ("Fix a misaligned load
inside ptrace_attach()"), there are now no users of non-long-aligned
calls to wait_on_bit*(). I additionally tried a few "make randconfig"
attempts, none of which failed to compile for this reason.

Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: bobby.prani@xxxxxxxxx
Cc: oleg@xxxxxxxxxx
Cc: paulmck@xxxxxxxxxxxxxxxxxx
Cc: richard@xxxxxx
Cc: vdavydov@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1430453997-32459-3-git-send-email-palmer@xxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/linux/wait.h | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/include/linux/wait.h b/include/linux/wait.h
index 2db8334..d69ac4e 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -969,7 +969,7 @@ extern int bit_wait_io_timeout(struct wait_bit_key *);
* on that signal.
*/
static inline int
-wait_on_bit(void *word, int bit, unsigned mode)
+wait_on_bit(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_bit(bit, word))
@@ -994,7 +994,7 @@ wait_on_bit(void *word, int bit, unsigned mode)
* on that signal.
*/
static inline int
-wait_on_bit_io(void *word, int bit, unsigned mode)
+wait_on_bit_io(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_bit(bit, word))
@@ -1020,7 +1020,8 @@ wait_on_bit_io(void *word, int bit, unsigned mode)
* received a signal and the mode permitted wakeup on that signal.
*/
static inline int
-wait_on_bit_timeout(void *word, int bit, unsigned mode, unsigned long timeout)
+wait_on_bit_timeout(unsigned long *word, int bit, unsigned mode,
+ unsigned long timeout)
{
might_sleep();
if (!test_bit(bit, word))
@@ -1047,7 +1048,8 @@ wait_on_bit_timeout(void *word, int bit, unsigned mode, unsigned long timeout)
* on that signal.
*/
static inline int
-wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
+wait_on_bit_action(unsigned long *word, int bit, wait_bit_action_f *action,
+ unsigned mode)
{
might_sleep();
if (!test_bit(bit, word))
@@ -1075,7 +1077,7 @@ wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode
* the @mode allows that signal to wake the process.
*/
static inline int
-wait_on_bit_lock(void *word, int bit, unsigned mode)
+wait_on_bit_lock(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_and_set_bit(bit, word))
@@ -1099,7 +1101,7 @@ wait_on_bit_lock(void *word, int bit, unsigned mode)
* the @mode allows that signal to wake the process.
*/
static inline int
-wait_on_bit_lock_io(void *word, int bit, unsigned mode)
+wait_on_bit_lock_io(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_and_set_bit(bit, word))
@@ -1125,7 +1127,8 @@ wait_on_bit_lock_io(void *word, int bit, unsigned mode)
* the @mode allows that signal to wake the process.
*/
static inline int
-wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
+wait_on_bit_lock_action(unsigned long *word, int bit, wait_bit_action_f *action,
+ unsigned mode)
{
might_sleep();
if (!test_and_set_bit(bit, word))
--
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