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| author | Sean Paul <seanpaul@chromium.org> | 2017-05-18 09:24:30 -0400 |
|---|---|---|
| committer | Sean Paul <seanpaul@chromium.org> | 2017-05-18 09:24:30 -0400 |
| commit | 6b7781b42dc9bc9bcd1523b6c24b876cdda0bef3 (patch) | |
| tree | ee55c67e4ea30b9eb44f301ba0bde2e631a26162 /include/linux/refcount.h | |
| parent | 52d9d38c183bf0e09601d875ea31bb53c05dd8cf (diff) | |
| parent | e98c58e55f68f8785aebfab1f8c9a03d8de0afe1 (diff) | |
| download | lwn-6b7781b42dc9bc9bcd1523b6c24b876cdda0bef3.tar.gz lwn-6b7781b42dc9bc9bcd1523b6c24b876cdda0bef3.zip | |
Merge remote-tracking branch 'airlied/drm-next' into drm-misc-next
Picking up drm-next @ 4.12-rc1 in order to apply Michal Hocko's vmalloc patch set
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Diffstat (limited to 'include/linux/refcount.h')
| -rw-r--r-- | include/linux/refcount.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/refcount.h b/include/linux/refcount.h index 0023fee4bbbc..b34aa649d204 100644 --- a/include/linux/refcount.h +++ b/include/linux/refcount.h @@ -6,17 +6,36 @@ #include <linux/spinlock.h> #include <linux/kernel.h> +/** + * refcount_t - variant of atomic_t specialized for reference counts + * @refs: atomic_t counter field + * + * The counter saturates at UINT_MAX and will not move once + * there. This avoids wrapping the counter and causing 'spurious' + * use-after-free bugs. + */ typedef struct refcount_struct { atomic_t refs; } refcount_t; #define REFCOUNT_INIT(n) { .refs = ATOMIC_INIT(n), } +/** + * refcount_set - set a refcount's value + * @r: the refcount + * @n: value to which the refcount will be set + */ static inline void refcount_set(refcount_t *r, unsigned int n) { atomic_set(&r->refs, n); } +/** + * refcount_read - get a refcount's value + * @r: the refcount + * + * Return: the refcount's value + */ static inline unsigned int refcount_read(const refcount_t *r) { return atomic_read(&r->refs); |
