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| author | Paul E. McKenney | 2019-04-09 16:48:18 +0200 |
|---|---|---|
| committer | Paul E. McKenney | 2019-05-28 18:02:57 +0200 |
| commit | 12edff045bc6dd3ab1565cc02fa4841803c2a633 (patch) | |
| tree | fd280d56ab640d856ac77c75060d62ea73a2daea /include/linux/rcupdate.h | |
| parent | rcu: Correctly unlock root node in rcu_check_gp_start_stall() (diff) | |
| download | kernel-qcow2-linux-12edff045bc6dd3ab1565cc02fa4841803c2a633.tar.gz kernel-qcow2-linux-12edff045bc6dd3ab1565cc02fa4841803c2a633.tar.xz kernel-qcow2-linux-12edff045bc6dd3ab1565cc02fa4841803c2a633.zip | |
rcu: Make kfree_rcu() ignore NULL pointers
This commit makes the kfree_rcu() macro's semantics be consistent
with the likes of kfree() by adding a check for NULL pointers, so
that kfree_rcu(NULL, ...) is a no-op.
Reported-by: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Reviewed-by: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 922bb6848813..915460ec0872 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -805,7 +805,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) /** * kfree_rcu() - kfree an object after a grace period. * @ptr: pointer to kfree - * @rcu_head: the name of the struct rcu_head within the type of @ptr. + * @rhf: the name of the struct rcu_head within the type of @ptr. * * Many rcu callbacks functions just call kfree() on the base structure. * These functions are trivial, but their size adds up, and furthermore @@ -828,9 +828,13 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) * The BUILD_BUG_ON check must not involve any function calls, hence the * checks are done in macros here. */ -#define kfree_rcu(ptr, rcu_head) \ - __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) - +#define kfree_rcu(ptr, rhf) \ +do { \ + typeof (ptr) ___p = (ptr); \ + \ + if (___p) \ + __kfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \ +} while (0) /* * Place this after a lock-acquisition primitive to guarantee that |