* [PATCH] futex: s/0/NULL/ in pointer context
@ 2005-01-09 9:23 Alexey Dobriyan
2005-01-09 14:19 ` Arnd Bergmann
0 siblings, 1 reply; 2+ messages in thread
From: Alexey Dobriyan @ 2005-01-09 9:23 UTC (permalink / raw)
To: Rusty Russell; +Cc: linux-kernel
Signed-off-by: Alexey Dobriyan <adobriyan@mail.ru>
Index: linux-2.6.10-bk11-warnings/kernel/futex.c
===================================================================
--- linux-2.6.10-bk11-warnings/kernel/futex.c (revision 4)
+++ linux-2.6.10-bk11-warnings/kernel/futex.c (revision 5)
@@ -236,7 +236,7 @@
*/
static inline void get_key_refs(union futex_key *key)
{
- if (key->both.ptr != 0) {
+ if (key->both.ptr != NULL) {
if (key->both.offset & 1)
atomic_inc(&key->shared.inode->i_count);
else
@@ -250,7 +250,7 @@
*/
static void drop_key_refs(union futex_key *key)
{
- if (key->both.ptr != 0) {
+ if (key->both.ptr != NULL) {
if (key->both.offset & 1)
iput(key->shared.inode);
else
@@ -445,7 +445,7 @@
/* In the common case we don't take the spinlock, which is nice. */
retry:
lock_ptr = q->lock_ptr;
- if (lock_ptr != 0) {
+ if (lock_ptr != NULL) {
spin_lock(lock_ptr);
/*
* q->lock_ptr can change between reading it and
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] futex: s/0/NULL/ in pointer context
2005-01-09 9:23 [PATCH] futex: s/0/NULL/ in pointer context Alexey Dobriyan
@ 2005-01-09 14:19 ` Arnd Bergmann
0 siblings, 0 replies; 2+ messages in thread
From: Arnd Bergmann @ 2005-01-09 14:19 UTC (permalink / raw)
To: Alexey Dobriyan; +Cc: Rusty Russell, linux-kernel
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On Sünndag 09 Januar 2005 10:23, Alexey Dobriyan wrote:
> @@ -236,7 +236,7 @@
> */
> static inline void get_key_refs(union futex_key *key)
> {
> - if (key->both.ptr != 0) {
> + if (key->both.ptr != NULL) {
> if (key->both.offset & 1)
> atomic_inc(&key->shared.inode->i_count);
> else
Actually, many consider the preferred way to write this
if (key->both.ptr) {
instead, since the condition you want to check is 'is key->both.ptr
a valid pointer', not 'is key->both.ptr inequal to the invalid
pointer'. The normal use for NULL is only in assignments and
initializations, not in comparisons.
Arnd <><
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2005-01-09 14:19 ` Arnd Bergmann
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