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-rw-r--r--lib/Kconfig.debug10
-rw-r--r--lib/genalloc.c3
-rw-r--r--lib/iov_iter.c22
-rw-r--r--lib/irq_poll.c2
-rw-r--r--lib/percpu-refcount.c169
-rw-r--r--lib/random32.c2
-rw-r--r--lib/stackdepot.c2
7 files changed, 123 insertions, 87 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 39d07e754822..b01e547d4d04 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -198,6 +198,7 @@ config FRAME_WARN
int "Warn for stack frames larger than (needs gcc 4.4)"
range 0 8192
default 0 if KASAN
+ default 2048 if GCC_PLUGIN_LATENT_ENTROPY
default 1024 if !64BIT
default 2048 if 64BIT
help
@@ -1857,15 +1858,6 @@ config PROVIDE_OHCI1394_DMA_INIT
See Documentation/debugging-via-ohci1394.txt for more information.
-config BUILD_DOCSRC
- bool "Build targets in Documentation/ tree"
- depends on HEADERS_CHECK
- help
- This option attempts to build objects from the source files in the
- kernel Documentation/ tree.
-
- Say N if you are unsure.
-
config DMA_API_DEBUG
bool "Enable debugging of DMA-API usage"
depends on HAVE_DMA_API_DEBUG
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 0a1139644d32..144fe6b1a03e 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -292,7 +292,7 @@ unsigned long gen_pool_alloc_algo(struct gen_pool *pool, size_t size,
struct gen_pool_chunk *chunk;
unsigned long addr = 0;
int order = pool->min_alloc_order;
- int nbits, start_bit = 0, end_bit, remain;
+ int nbits, start_bit, end_bit, remain;
#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
BUG_ON(in_nmi());
@@ -307,6 +307,7 @@ unsigned long gen_pool_alloc_algo(struct gen_pool *pool, size_t size,
if (size > atomic_read(&chunk->avail))
continue;
+ start_bit = 0;
end_bit = chunk_size(chunk) >> order;
retry:
start_bit = algo(chunk->bits, end_bit, start_bit,
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 7312e7784611..f0c7f1481bae 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1139,6 +1139,28 @@ const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags)
}
EXPORT_SYMBOL(dup_iter);
+/**
+ * import_iovec() - Copy an array of &struct iovec from userspace
+ * into the kernel, check that it is valid, and initialize a new
+ * &struct iov_iter iterator to access it.
+ *
+ * @type: One of %READ or %WRITE.
+ * @uvector: Pointer to the userspace array.
+ * @nr_segs: Number of elements in userspace array.
+ * @fast_segs: Number of elements in @iov.
+ * @iov: (input and output parameter) Pointer to pointer to (usually small
+ * on-stack) kernel array.
+ * @i: Pointer to iterator that will be initialized on success.
+ *
+ * If the array pointed to by *@iov is large enough to hold all @nr_segs,
+ * then this function places %NULL in *@iov on return. Otherwise, a new
+ * array will be allocated and the result placed in *@iov. This means that
+ * the caller may call kfree() on *@iov regardless of whether the small
+ * on-stack array was used or not (and regardless of whether this function
+ * returns an error or not).
+ *
+ * Return: 0 on success or negative error code on error.
+ */
int import_iovec(int type, const struct iovec __user * uvector,
unsigned nr_segs, unsigned fast_segs,
struct iovec **iov, struct iov_iter *i)
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 2be55692aa43..1d6565e81030 100644
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -74,7 +74,7 @@ void irq_poll_complete(struct irq_poll *iop)
}
EXPORT_SYMBOL(irq_poll_complete);
-static void irq_poll_softirq(struct softirq_action *h)
+static void __latent_entropy irq_poll_softirq(struct softirq_action *h)
{
struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
int rearm = 0, budget = irq_poll_budget;
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 27fe74948882..9ac959ef4cae 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -33,6 +33,7 @@
#define PERCPU_COUNT_BIAS (1LU << (BITS_PER_LONG - 1))
+static DEFINE_SPINLOCK(percpu_ref_switch_lock);
static DECLARE_WAIT_QUEUE_HEAD(percpu_ref_switch_waitq);
static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref)
@@ -82,6 +83,7 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,
atomic_long_set(&ref->count, start_count);
ref->release = release;
+ ref->confirm_switch = NULL;
return 0;
}
EXPORT_SYMBOL_GPL(percpu_ref_init);
@@ -101,6 +103,8 @@ void percpu_ref_exit(struct percpu_ref *ref)
unsigned long __percpu *percpu_count = percpu_count_ptr(ref);
if (percpu_count) {
+ /* non-NULL confirm_switch indicates switching in progress */
+ WARN_ON_ONCE(ref->confirm_switch);
free_percpu(percpu_count);
ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;
}
@@ -161,66 +165,23 @@ static void percpu_ref_noop_confirm_switch(struct percpu_ref *ref)
static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,
percpu_ref_func_t *confirm_switch)
{
- if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC)) {
- /* switching from percpu to atomic */
- ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;
-
- /*
- * Non-NULL ->confirm_switch is used to indicate that
- * switching is in progress. Use noop one if unspecified.
- */
- WARN_ON_ONCE(ref->confirm_switch);
- ref->confirm_switch =
- confirm_switch ?: percpu_ref_noop_confirm_switch;
-
- percpu_ref_get(ref); /* put after confirmation */
- call_rcu_sched(&ref->rcu, percpu_ref_switch_to_atomic_rcu);
- } else if (confirm_switch) {
- /*
- * Somebody already set ATOMIC. Switching may still be in
- * progress. @confirm_switch must be invoked after the
- * switching is complete and a full sched RCU grace period
- * has passed. Wait synchronously for the previous
- * switching and schedule @confirm_switch invocation.
- */
- wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);
- ref->confirm_switch = confirm_switch;
-
- percpu_ref_get(ref); /* put after confirmation */
- call_rcu_sched(&ref->rcu, percpu_ref_call_confirm_rcu);
+ if (ref->percpu_count_ptr & __PERCPU_REF_ATOMIC) {
+ if (confirm_switch)
+ confirm_switch(ref);
+ return;
}
-}
-/**
- * percpu_ref_switch_to_atomic - switch a percpu_ref to atomic mode
- * @ref: percpu_ref to switch to atomic mode
- * @confirm_switch: optional confirmation callback
- *
- * There's no reason to use this function for the usual reference counting.
- * Use percpu_ref_kill[_and_confirm]().
- *
- * Schedule switching of @ref to atomic mode. All its percpu counts will
- * be collected to the main atomic counter. On completion, when all CPUs
- * are guaraneed to be in atomic mode, @confirm_switch, which may not
- * block, is invoked. This function may be invoked concurrently with all
- * the get/put operations and can safely be mixed with kill and reinit
- * operations. Note that @ref will stay in atomic mode across kill/reinit
- * cycles until percpu_ref_switch_to_percpu() is called.
- *
- * This function normally doesn't block and can be called from any context
- * but it may block if @confirm_kill is specified and @ref is already in
- * the process of switching to atomic mode. In such cases, @confirm_switch
- * will be invoked after the switching is complete.
- *
- * Due to the way percpu_ref is implemented, @confirm_switch will be called
- * after at least one full sched RCU grace period has passed but this is an
- * implementation detail and must not be depended upon.
- */
-void percpu_ref_switch_to_atomic(struct percpu_ref *ref,
- percpu_ref_func_t *confirm_switch)
-{
- ref->force_atomic = true;
- __percpu_ref_switch_to_atomic(ref, confirm_switch);
+ /* switching from percpu to atomic */
+ ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;
+
+ /*
+ * Non-NULL ->confirm_switch is used to indicate that switching is
+ * in progress. Use noop one if unspecified.
+ */
+ ref->confirm_switch = confirm_switch ?: percpu_ref_noop_confirm_switch;
+
+ percpu_ref_get(ref); /* put after confirmation */
+ call_rcu_sched(&ref->rcu, percpu_ref_switch_to_atomic_rcu);
}
static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
@@ -233,8 +194,6 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))
return;
- wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);
-
atomic_long_add(PERCPU_COUNT_BIAS, &ref->count);
/*
@@ -250,6 +209,58 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC);
}
+static void __percpu_ref_switch_mode(struct percpu_ref *ref,
+ percpu_ref_func_t *confirm_switch)
+{
+ lockdep_assert_held(&percpu_ref_switch_lock);
+
+ /*
+ * If the previous ATOMIC switching hasn't finished yet, wait for
+ * its completion. If the caller ensures that ATOMIC switching
+ * isn't in progress, this function can be called from any context.
+ */
+ wait_event_lock_irq(percpu_ref_switch_waitq, !ref->confirm_switch,
+ percpu_ref_switch_lock);
+
+ if (ref->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))
+ __percpu_ref_switch_to_atomic(ref, confirm_switch);
+ else
+ __percpu_ref_switch_to_percpu(ref);
+}
+
+/**
+ * percpu_ref_switch_to_atomic - switch a percpu_ref to atomic mode
+ * @ref: percpu_ref to switch to atomic mode
+ * @confirm_switch: optional confirmation callback
+ *
+ * There's no reason to use this function for the usual reference counting.
+ * Use percpu_ref_kill[_and_confirm]().
+ *
+ * Schedule switching of @ref to atomic mode. All its percpu counts will
+ * be collected to the main atomic counter. On completion, when all CPUs
+ * are guaraneed to be in atomic mode, @confirm_switch, which may not
+ * block, is invoked. This function may be invoked concurrently with all
+ * the get/put operations and can safely be mixed with kill and reinit
+ * operations. Note that @ref will stay in atomic mode across kill/reinit
+ * cycles until percpu_ref_switch_to_percpu() is called.
+ *
+ * This function may block if @ref is in the process of switching to atomic
+ * mode. If the caller ensures that @ref is not in the process of
+ * switching to atomic mode, this function can be called from any context.
+ */
+void percpu_ref_switch_to_atomic(struct percpu_ref *ref,
+ percpu_ref_func_t *confirm_switch)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&percpu_ref_switch_lock, flags);
+
+ ref->force_atomic = true;
+ __percpu_ref_switch_mode(ref, confirm_switch);
+
+ spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
+}
+
/**
* percpu_ref_switch_to_percpu - switch a percpu_ref to percpu mode
* @ref: percpu_ref to switch to percpu mode
@@ -264,17 +275,20 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
* dying or dead, the actual switching takes place on the following
* percpu_ref_reinit().
*
- * This function normally doesn't block and can be called from any context
- * but it may block if @ref is in the process of switching to atomic mode
- * by percpu_ref_switch_atomic().
+ * This function may block if @ref is in the process of switching to atomic
+ * mode. If the caller ensures that @ref is not in the process of
+ * switching to atomic mode, this function can be called from any context.
*/
void percpu_ref_switch_to_percpu(struct percpu_ref *ref)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&percpu_ref_switch_lock, flags);
+
ref->force_atomic = false;
+ __percpu_ref_switch_mode(ref, NULL);
- /* a dying or dead ref can't be switched to percpu mode w/o reinit */
- if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD))
- __percpu_ref_switch_to_percpu(ref);
+ spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
}
/**
@@ -290,21 +304,23 @@ void percpu_ref_switch_to_percpu(struct percpu_ref *ref)
*
* This function normally doesn't block and can be called from any context
* but it may block if @confirm_kill is specified and @ref is in the
- * process of switching to atomic mode by percpu_ref_switch_atomic().
- *
- * Due to the way percpu_ref is implemented, @confirm_switch will be called
- * after at least one full sched RCU grace period has passed but this is an
- * implementation detail and must not be depended upon.
+ * process of switching to atomic mode by percpu_ref_switch_to_atomic().
*/
void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
percpu_ref_func_t *confirm_kill)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&percpu_ref_switch_lock, flags);
+
WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,
"%s called more than once on %pf!", __func__, ref->release);
ref->percpu_count_ptr |= __PERCPU_REF_DEAD;
- __percpu_ref_switch_to_atomic(ref, confirm_kill);
+ __percpu_ref_switch_mode(ref, confirm_kill);
percpu_ref_put(ref);
+
+ spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
}
EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm);
@@ -321,11 +337,16 @@ EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm);
*/
void percpu_ref_reinit(struct percpu_ref *ref)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&percpu_ref_switch_lock, flags);
+
WARN_ON_ONCE(!percpu_ref_is_zero(ref));
ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;
percpu_ref_get(ref);
- if (!ref->force_atomic)
- __percpu_ref_switch_to_percpu(ref);
+ __percpu_ref_switch_mode(ref, NULL);
+
+ spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
}
EXPORT_SYMBOL_GPL(percpu_ref_reinit);
diff --git a/lib/random32.c b/lib/random32.c
index 915982b304bb..fa594b1140e6 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -47,7 +47,7 @@ static inline void prandom_state_selftest(void)
}
#endif
-static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
+static DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy;
/**
* prandom_u32_state - seeded pseudo-random number generator.
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 60f77f1d470a..4d830e299989 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -50,7 +50,7 @@
STACK_ALLOC_ALIGN)
#define STACK_ALLOC_INDEX_BITS (DEPOT_STACK_BITS - \
STACK_ALLOC_NULL_PROTECTION_BITS - STACK_ALLOC_OFFSET_BITS)
-#define STACK_ALLOC_SLABS_CAP 1024
+#define STACK_ALLOC_SLABS_CAP 8192
#define STACK_ALLOC_MAX_SLABS \
(((1LL << (STACK_ALLOC_INDEX_BITS)) < STACK_ALLOC_SLABS_CAP) ? \
(1LL << (STACK_ALLOC_INDEX_BITS)) : STACK_ALLOC_SLABS_CAP)