Merge tag 'docs-5.10' of git://git.lwn.net/linux

[linux-2.6-microblaze.git] / include / linux / refcount.h

diff --git a/include/linux/refcount.h b/include/linux/refcount.h
index 0e3ee25..7fabb1a 100644 (file)
--- a/include/linux/refcount.h
+++ b/include/linux/refcount.h
@@ -165,7 +165,7 @@ static inline unsigned int refcount_read(const refcount_t *r)
  *
  * Return: false if the passed refcount is 0, true otherwise
  */
-static inline __must_check bool refcount_add_not_zero(int i, refcount_t *r)
+static inline __must_check bool __refcount_add_not_zero(int i, refcount_t *r, int *oldp)
 {
        int old = refcount_read(r);
 
@@ -174,12 +174,20 @@ static inline __must_check bool refcount_add_not_zero(int i, refcount_t *r)
                        break;
        } while (!atomic_try_cmpxchg_relaxed(&r->refs, &old, old + i));
 
+       if (oldp)
+               *oldp = old;
+
        if (unlikely(old < 0 || old + i < 0))
                refcount_warn_saturate(r, REFCOUNT_ADD_NOT_ZERO_OVF);
 
        return old;
 }
 
+static inline __must_check bool refcount_add_not_zero(int i, refcount_t *r)
+{
+       return __refcount_add_not_zero(i, r, NULL);
+}
+
 /**
  * refcount_add - add a value to a refcount
  * @i: the value to add to the refcount
@@ -196,16 +204,24 @@ static inline __must_check bool refcount_add_not_zero(int i, refcount_t *r)
  * cases, refcount_inc(), or one of its variants, should instead be used to
  * increment a reference count.
  */
-static inline void refcount_add(int i, refcount_t *r)
+static inline void __refcount_add(int i, refcount_t *r, int *oldp)
 {
        int old = atomic_fetch_add_relaxed(i, &r->refs);
 
+       if (oldp)
+               *oldp = old;
+
        if (unlikely(!old))
                refcount_warn_saturate(r, REFCOUNT_ADD_UAF);
        else if (unlikely(old < 0 || old + i < 0))
                refcount_warn_saturate(r, REFCOUNT_ADD_OVF);
 }
 
+static inline void refcount_add(int i, refcount_t *r)
+{
+       __refcount_add(i, r, NULL);
+}
+
 /**
  * refcount_inc_not_zero - increment a refcount unless it is 0
  * @r: the refcount to increment
@@ -219,9 +235,14 @@ static inline void refcount_add(int i, refcount_t *r)
  *
  * Return: true if the increment was successful, false otherwise
  */
+static inline __must_check bool __refcount_inc_not_zero(refcount_t *r, int *oldp)
+{
+       return __refcount_add_not_zero(1, r, oldp);
+}
+
 static inline __must_check bool refcount_inc_not_zero(refcount_t *r)
 {
-       return refcount_add_not_zero(1, r);
+       return __refcount_inc_not_zero(r, NULL);
 }
 
 /**
@@ -236,9 +257,14 @@ static inline __must_check bool refcount_inc_not_zero(refcount_t *r)
  * Will WARN if the refcount is 0, as this represents a possible use-after-free
  * condition.
  */
+static inline void __refcount_inc(refcount_t *r, int *oldp)
+{
+       __refcount_add(1, r, oldp);
+}
+
 static inline void refcount_inc(refcount_t *r)
 {
-       refcount_add(1, r);
+       __refcount_inc(r, NULL);
 }
 
 /**
@@ -261,10 +287,13 @@ static inline void refcount_inc(refcount_t *r)
  *
  * Return: true if the resulting refcount is 0, false otherwise
  */
-static inline __must_check bool refcount_sub_and_test(int i, refcount_t *r)
+static inline __must_check bool __refcount_sub_and_test(int i, refcount_t *r, int *oldp)
 {
        int old = atomic_fetch_sub_release(i, &r->refs);
 
+       if (oldp)
+               *oldp = old;
+
        if (old == i) {
                smp_acquire__after_ctrl_dep();
                return true;
@@ -276,6 +305,11 @@ static inline __must_check bool refcount_sub_and_test(int i, refcount_t *r)
        return false;
 }
 
+static inline __must_check bool refcount_sub_and_test(int i, refcount_t *r)
+{
+       return __refcount_sub_and_test(i, r, NULL);
+}
+
 /**
  * refcount_dec_and_test - decrement a refcount and test if it is 0
  * @r: the refcount
@@ -289,9 +323,14 @@ static inline __must_check bool refcount_sub_and_test(int i, refcount_t *r)
  *
  * Return: true if the resulting refcount is 0, false otherwise
  */
+static inline __must_check bool __refcount_dec_and_test(refcount_t *r, int *oldp)
+{
+       return __refcount_sub_and_test(1, r, oldp);
+}
+
 static inline __must_check bool refcount_dec_and_test(refcount_t *r)
 {
-       return refcount_sub_and_test(1, r);
+       return __refcount_dec_and_test(r, NULL);
 }
 
 /**
@@ -304,12 +343,22 @@ static inline __must_check bool refcount_dec_and_test(refcount_t *r)
  * Provides release memory ordering, such that prior loads and stores are done
  * before.
  */
-static inline void refcount_dec(refcount_t *r)
+static inline void __refcount_dec(refcount_t *r, int *oldp)
 {
-       if (unlikely(atomic_fetch_sub_release(1, &r->refs) <= 1))
+       int old = atomic_fetch_sub_release(1, &r->refs);
+
+       if (oldp)
+               *oldp = old;
+
+       if (unlikely(old <= 1))
                refcount_warn_saturate(r, REFCOUNT_DEC_LEAK);
 }
 
+static inline void refcount_dec(refcount_t *r)
+{
+       __refcount_dec(r, NULL);
+}
+
 extern __must_check bool refcount_dec_if_one(refcount_t *r);
 extern __must_check bool refcount_dec_not_one(refcount_t *r);
 extern __must_check bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock);