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| author | Sean Paul <seanpaul@chromium.org> | 2017-06-19 20:39:28 +0300 |
|---|---|---|
| committer | Sean Paul <seanpaul@chromium.org> | 2017-06-19 20:39:28 +0300 |
| commit | d4e0045c4ed300781d2d4cbab57d05ed5e665a37 (patch) | |
| tree | 925bab41d7906329392aa12c8fa7bcc70f64ca46 /include/linux/refcount.h | |
| parent | 2d7b56378d32b0cf006f8944cbba4046df45dd25 (diff) | |
| parent | 41f1830f5a7af77cf5c86359aba3cbd706687e52 (diff) | |
| download | linux-d4e0045c4ed300781d2d4cbab57d05ed5e665a37.tar.xz | |
Merge remote-tracking branch 'origin/master' into drm-misc-next-fixes
Backmerge 4.12-rc6 into -next-fixes. -next-fixes will contain find patches
for 4.13 merge window
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); |
