diff options
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 2472740d7ab2..4a3caa61a002 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -364,6 +364,21 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); */ #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) +/** + * lockless_dereference() - safely load a pointer for later dereference + * @p: The pointer to load + * + * Similar to rcu_dereference(), but for situations where the pointed-to + * object's lifetime is managed by something other than RCU. That + * "something other" might be reference counting or simple immortality. + */ +#define lockless_dereference(p) \ +({ \ + typeof(p) _________p1 = ACCESS_ONCE(p); \ + smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ + (_________p1); \ +}) + /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */ #ifdef CONFIG_KPROBES # define __kprobes __attribute__((__section__(".kprobes.text"))) |