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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-03-08 10:00:40 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2017-03-08 17:46:03 -0500 |
| commit | 4b9502e63b5e2b1b5ef491919d3219b9440fe0b3 (patch) | |
| tree | 75ede84d703f3e230322be6f11b87625ba9ab72f /kernel/cgroup/cgroup-internal.h | |
| parent | 387ad9674b0013c8756ad20d854ff005b0c313ad (diff) | |
| download | lwn-4b9502e63b5e2b1b5ef491919d3219b9440fe0b3.tar.gz lwn-4b9502e63b5e2b1b5ef491919d3219b9440fe0b3.zip | |
kernel: convert css_set.refcount from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup/cgroup-internal.h')
| -rw-r--r-- | kernel/cgroup/cgroup-internal.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 9203bfb05603..4567f12b02e9 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -5,6 +5,7 @@ #include <linux/kernfs.h> #include <linux/workqueue.h> #include <linux/list.h> +#include <linux/refcount.h> /* * A cgroup can be associated with multiple css_sets as different tasks may @@ -134,7 +135,7 @@ static inline void put_css_set(struct css_set *cset) * can see it. Similar to atomic_dec_and_lock(), but for an * rwlock */ - if (atomic_add_unless(&cset->refcount, -1, 1)) + if (refcount_dec_not_one(&cset->refcount)) return; spin_lock_irqsave(&css_set_lock, flags); @@ -147,7 +148,7 @@ static inline void put_css_set(struct css_set *cset) */ static inline void get_css_set(struct css_set *cset) { - atomic_inc(&cset->refcount); + refcount_inc(&cset->refcount); } bool cgroup_ssid_enabled(int ssid); |