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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 22:23:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 22:23:39 +0300
commitde5d1b39ea0b38a9f4dfb08966042b7b91e2df30 (patch)
tree3591bdac4fe6756b4e3dc68b2ed1c792c4104218 /lib
parent1c594774283a7cfe6dc0f8ffdfb2dbfc497502c4 (diff)
parentfd2efaa4eb5317c3a86357a83a7d456a1b86a0ac (diff)
downloadlinux-de5d1b39ea0b38a9f4dfb08966042b7b91e2df30.tar.xz
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking/atomics update from Thomas Gleixner: "The locking, atomics and memory model brains delivered: - A larger update to the atomics code which reworks the ordering barriers, consolidates the atomic primitives, provides the new atomic64_fetch_add_unless() primitive and cleans up the include hell. - Simplify cmpxchg() instrumentation and add instrumentation for xchg() and cmpxchg_double(). - Updates to the memory model and documentation" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/atomics: Rework ordering barriers locking/atomics: Instrument cmpxchg_double*() locking/atomics: Instrument xchg() locking/atomics: Simplify cmpxchg() instrumentation locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation tools/memory-model: Rename litmus tests to comply to norm7 tools/memory-model/Documentation: Fix typo, smb->smp sched/Documentation: Update wake_up() & co. memory-barrier guarantees locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock() sched/core: Use smp_mb() in wake_woken_function() tools/memory-model: Add informal LKMM documentation to MAINTAINERS locking/atomics/Documentation: Describe atomic_set() as a write operation tools/memory-model: Make scripts executable tools/memory-model: Remove ACCESS_ONCE() from model tools/memory-model: Remove ACCESS_ONCE() from recipes locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example MAINTAINERS: Add Daniel Lustig as an LKMM reviewer tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name tools/memory-model: Add litmus test for full multicopy atomicity locking/refcount: Always allow checked forms ...
Diffstat (limited to 'lib')
-rw-r--r--lib/atomic64.c14
-rw-r--r--lib/refcount.c55
2 files changed, 34 insertions, 35 deletions
diff --git a/lib/atomic64.c b/lib/atomic64.c
index 53c2d5edc826..1d91e31eceec 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -178,18 +178,18 @@ long long atomic64_xchg(atomic64_t *v, long long new)
}
EXPORT_SYMBOL(atomic64_xchg);
-int atomic64_add_unless(atomic64_t *v, long long a, long long u)
+long long atomic64_fetch_add_unless(atomic64_t *v, long long a, long long u)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
- int ret = 0;
+ long long val;
raw_spin_lock_irqsave(lock, flags);
- if (v->counter != u) {
+ val = v->counter;
+ if (val != u)
v->counter += a;
- ret = 1;
- }
raw_spin_unlock_irqrestore(lock, flags);
- return ret;
+
+ return val;
}
-EXPORT_SYMBOL(atomic64_add_unless);
+EXPORT_SYMBOL(atomic64_fetch_add_unless);
diff --git a/lib/refcount.c b/lib/refcount.c
index d3b81cefce91..ebcf8cd49e05 100644
--- a/lib/refcount.c
+++ b/lib/refcount.c
@@ -35,13 +35,13 @@
*
*/
+#include <linux/mutex.h>
#include <linux/refcount.h>
+#include <linux/spinlock.h>
#include <linux/bug.h>
-#ifdef CONFIG_REFCOUNT_FULL
-
/**
- * refcount_add_not_zero - add a value to a refcount unless it is 0
+ * refcount_add_not_zero_checked - add a value to a refcount unless it is 0
* @i: the value to add to the refcount
* @r: the refcount
*
@@ -58,7 +58,7 @@
*
* Return: false if the passed refcount is 0, true otherwise
*/
-bool refcount_add_not_zero(unsigned int i, refcount_t *r)
+bool refcount_add_not_zero_checked(unsigned int i, refcount_t *r)
{
unsigned int new, val = atomic_read(&r->refs);
@@ -79,10 +79,10 @@ bool refcount_add_not_zero(unsigned int i, refcount_t *r)
return true;
}
-EXPORT_SYMBOL(refcount_add_not_zero);
+EXPORT_SYMBOL(refcount_add_not_zero_checked);
/**
- * refcount_add - add a value to a refcount
+ * refcount_add_checked - add a value to a refcount
* @i: the value to add to the refcount
* @r: the refcount
*
@@ -97,14 +97,14 @@ EXPORT_SYMBOL(refcount_add_not_zero);
* cases, refcount_inc(), or one of its variants, should instead be used to
* increment a reference count.
*/
-void refcount_add(unsigned int i, refcount_t *r)
+void refcount_add_checked(unsigned int i, refcount_t *r)
{
- WARN_ONCE(!refcount_add_not_zero(i, r), "refcount_t: addition on 0; use-after-free.\n");
+ WARN_ONCE(!refcount_add_not_zero_checked(i, r), "refcount_t: addition on 0; use-after-free.\n");
}
-EXPORT_SYMBOL(refcount_add);
+EXPORT_SYMBOL(refcount_add_checked);
/**
- * refcount_inc_not_zero - increment a refcount unless it is 0
+ * refcount_inc_not_zero_checked - increment a refcount unless it is 0
* @r: the refcount to increment
*
* Similar to atomic_inc_not_zero(), but will saturate at UINT_MAX and WARN.
@@ -115,7 +115,7 @@ EXPORT_SYMBOL(refcount_add);
*
* Return: true if the increment was successful, false otherwise
*/
-bool refcount_inc_not_zero(refcount_t *r)
+bool refcount_inc_not_zero_checked(refcount_t *r)
{
unsigned int new, val = atomic_read(&r->refs);
@@ -134,10 +134,10 @@ bool refcount_inc_not_zero(refcount_t *r)
return true;
}
-EXPORT_SYMBOL(refcount_inc_not_zero);
+EXPORT_SYMBOL(refcount_inc_not_zero_checked);
/**
- * refcount_inc - increment a refcount
+ * refcount_inc_checked - increment a refcount
* @r: the refcount to increment
*
* Similar to atomic_inc(), but will saturate at UINT_MAX and WARN.
@@ -148,14 +148,14 @@ EXPORT_SYMBOL(refcount_inc_not_zero);
* Will WARN if the refcount is 0, as this represents a possible use-after-free
* condition.
*/
-void refcount_inc(refcount_t *r)
+void refcount_inc_checked(refcount_t *r)
{
- WARN_ONCE(!refcount_inc_not_zero(r), "refcount_t: increment on 0; use-after-free.\n");
+ WARN_ONCE(!refcount_inc_not_zero_checked(r), "refcount_t: increment on 0; use-after-free.\n");
}
-EXPORT_SYMBOL(refcount_inc);
+EXPORT_SYMBOL(refcount_inc_checked);
/**
- * refcount_sub_and_test - subtract from a refcount and test if it is 0
+ * refcount_sub_and_test_checked - subtract from a refcount and test if it is 0
* @i: amount to subtract from the refcount
* @r: the refcount
*
@@ -174,7 +174,7 @@ EXPORT_SYMBOL(refcount_inc);
*
* Return: true if the resulting refcount is 0, false otherwise
*/
-bool refcount_sub_and_test(unsigned int i, refcount_t *r)
+bool refcount_sub_and_test_checked(unsigned int i, refcount_t *r)
{
unsigned int new, val = atomic_read(&r->refs);
@@ -192,10 +192,10 @@ bool refcount_sub_and_test(unsigned int i, refcount_t *r)
return !new;
}
-EXPORT_SYMBOL(refcount_sub_and_test);
+EXPORT_SYMBOL(refcount_sub_and_test_checked);
/**
- * refcount_dec_and_test - decrement a refcount and test if it is 0
+ * refcount_dec_and_test_checked - decrement a refcount and test if it is 0
* @r: the refcount
*
* Similar to atomic_dec_and_test(), it will WARN on underflow and fail to
@@ -207,14 +207,14 @@ EXPORT_SYMBOL(refcount_sub_and_test);
*
* Return: true if the resulting refcount is 0, false otherwise
*/
-bool refcount_dec_and_test(refcount_t *r)
+bool refcount_dec_and_test_checked(refcount_t *r)
{
- return refcount_sub_and_test(1, r);
+ return refcount_sub_and_test_checked(1, r);
}
-EXPORT_SYMBOL(refcount_dec_and_test);
+EXPORT_SYMBOL(refcount_dec_and_test_checked);
/**
- * refcount_dec - decrement a refcount
+ * refcount_dec_checked - decrement a refcount
* @r: the refcount
*
* Similar to atomic_dec(), it will WARN on underflow and fail to decrement
@@ -223,12 +223,11 @@ EXPORT_SYMBOL(refcount_dec_and_test);
* Provides release memory ordering, such that prior loads and stores are done
* before.
*/
-void refcount_dec(refcount_t *r)
+void refcount_dec_checked(refcount_t *r)
{
- WARN_ONCE(refcount_dec_and_test(r), "refcount_t: decrement hit 0; leaking memory.\n");
+ WARN_ONCE(refcount_dec_and_test_checked(r), "refcount_t: decrement hit 0; leaking memory.\n");
}
-EXPORT_SYMBOL(refcount_dec);
-#endif /* CONFIG_REFCOUNT_FULL */
+EXPORT_SYMBOL(refcount_dec_checked);
/**
* refcount_dec_if_one - decrement a refcount if it is 1