Merge tag 'v4.2-rc7' into drm-next

Linux 4.2-rc7

Backmerge master for i915 fixes

8 files changed, 138 insertions, 57 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d3dae3419b99..e6feb5114134 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1868,8 +1868,6 @@ event_sched_in(struct perf_event *event,
 
         perf_pmu_disable(event->pmu);
 
-        event->tstamp_running += tstamp - event->tstamp_stopped;
-
         perf_set_shadow_time(event, ctx, tstamp);
 
         perf_log_itrace_start(event);
@@ -1881,6 +1879,8 @@ event_sched_in(struct perf_event *event,
                 goto out;
         }
 
+        event->tstamp_running += tstamp - event->tstamp_stopped;
+
         if (!is_software_event(event))
                 cpuctx->active_oncpu++;
         if (!ctx->nr_active++)
@@ -3958,28 +3958,21 @@ static void perf_event_for_each(struct perf_event *event,
                 perf_event_for_each_child(sibling, func);
 }
 
-static int perf_event_period(struct perf_event *event, u64 __user *arg)
-{
-        struct perf_event_context *ctx = event->ctx;
-        int ret = 0, active;
+struct period_event {
+        struct perf_event *event;
         u64 value;
+};
 
-        if (!is_sampling_event(event))
-                return -EINVAL;
-
-        if (copy_from_user(&value, arg, sizeof(value)))
-                return -EFAULT;
-
-        if (!value)
-                return -EINVAL;
+static int __perf_event_period(void *info)
+{
+        struct period_event *pe = info;
+        struct perf_event *event = pe->event;
+        struct perf_event_context *ctx = event->ctx;
+        u64 value = pe->value;
+        bool active;
 
-        raw_spin_lock_irq(&ctx->lock);
+        raw_spin_lock(&ctx->lock);
         if (event->attr.freq) {
-                if (value > sysctl_perf_event_sample_rate) {
-                        ret = -EINVAL;
-                        goto unlock;
-                }
-
                 event->attr.sample_freq = value;
         } else {
                 event->attr.sample_period = value;
@@ -3998,11 +3991,53 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg)
                 event->pmu->start(event, PERF_EF_RELOAD);
                 perf_pmu_enable(ctx->pmu);
         }
+        raw_spin_unlock(&ctx->lock);
 
-unlock:
+        return 0;
+}
+
+static int perf_event_period(struct perf_event *event, u64 __user *arg)
+{
+        struct period_event pe = { .event = event, };
+        struct perf_event_context *ctx = event->ctx;
+        struct task_struct *task;
+        u64 value;
+
+        if (!is_sampling_event(event))
+                return -EINVAL;
+
+        if (copy_from_user(&value, arg, sizeof(value)))
+                return -EFAULT;
+
+        if (!value)
+                return -EINVAL;
+
+        if (event->attr.freq && value > sysctl_perf_event_sample_rate)
+                return -EINVAL;
+
+        task = ctx->task;
+        pe.value = value;
+
+        if (!task) {
+                cpu_function_call(event->cpu, __perf_event_period, &pe);
+                return 0;
+        }
+
+retry:
+        if (!task_function_call(task, __perf_event_period, &pe))
+                return 0;
+
+        raw_spin_lock_irq(&ctx->lock);
+        if (ctx->is_active) {
+                raw_spin_unlock_irq(&ctx->lock);
+                task = ctx->task;
+                goto retry;
+        }
+
+        __perf_event_period(&pe);
         raw_spin_unlock_irq(&ctx->lock);
 
-        return ret;
+        return 0;
 }
 
 static const struct file_operations perf_fops;
@@ -4740,12 +4775,20 @@ static const struct file_operations perf_fops = {
  * to user-space before waking everybody up.
  */
 
+static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
+{
+        /* only the parent has fasync state */
+        if (event->parent)
+                event = event->parent;
+        return &event->fasync;
+}
+
 void perf_event_wakeup(struct perf_event *event)
 {
         ring_buffer_wakeup(event);
 
         if (event->pending_kill) {
-                kill_fasync(&event->fasync, SIGIO, event->pending_kill);
+                kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
                 event->pending_kill = 0;
         }
 }
@@ -6124,7 +6167,7 @@ static int __perf_event_overflow(struct perf_event *event,
         else
                 perf_event_output(event, data, regs);
 
-        if (event->fasync && event->pending_kill) {
+        if (*perf_event_fasync(event) && event->pending_kill) {
                 event->pending_wakeup = 1;
                 irq_work_queue(&event->pending);
         }
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index b2be01b1aa9d..c8aa3f75bc4d 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -559,11 +559,13 @@ static void __rb_free_aux(struct ring_buffer *rb)
                 rb->aux_priv = NULL;
         }
 
-        for (pg = 0; pg < rb->aux_nr_pages; pg++)
-                rb_free_aux_page(rb, pg);
+        if (rb->aux_nr_pages) {
+                for (pg = 0; pg < rb->aux_nr_pages; pg++)
+                        rb_free_aux_page(rb, pg);
 
-        kfree(rb->aux_pages);
-        rb->aux_nr_pages = 0;
+                kfree(rb->aux_pages);
+                rb->aux_nr_pages = 0;
+        }
 }
 
 void rb_free_aux(struct ring_buffer *rb)
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 10e489c448fe..fdea0bee7b5a 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -97,6 +97,7 @@ bool kthread_should_park(void)
 {
         return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(current)->flags);
 }
+EXPORT_SYMBOL_GPL(kthread_should_park);
 
 /**
  * kthread_freezable_should_stop - should this freezable kthread return now?
@@ -171,6 +172,7 @@ void kthread_parkme(void)
 {
         __kthread_parkme(to_kthread(current));
 }
+EXPORT_SYMBOL_GPL(kthread_parkme);
 
 static int kthread(void *_create)
 {
@@ -411,6 +413,7 @@ void kthread_unpark(struct task_struct *k)
         if (kthread)
                 __kthread_unpark(k, kthread);
 }
+EXPORT_SYMBOL_GPL(kthread_unpark);
 
 /**
  * kthread_park - park a thread created by kthread_create().
@@ -441,6 +444,7 @@ int kthread_park(struct task_struct *k)
         }
         return ret;
 }
+EXPORT_SYMBOL_GPL(kthread_park);
 
 /**
  * kthread_stop - stop a thread created by kthread_create().
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 04ab18151cc8..df19ae4debd0 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -4,6 +4,7 @@
 
 #include <linux/hash.h>
 #include <linux/bootmem.h>
+#include <linux/debug_locks.h>
 
 /*
  * Implement paravirt qspinlocks; the general idea is to halt the vcpus instead
@@ -286,15 +287,23 @@ __visible void __pv_queued_spin_unlock(struct qspinlock *lock)
 {
         struct __qspinlock *l = (void *)lock;
         struct pv_node *node;
+        u8 lockval = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
 
         /*
          * We must not unlock if SLOW, because in that case we must first
          * unhash. Otherwise it would be possible to have multiple @lock
          * entries, which would be BAD.
          */
-        if (likely(cmpxchg(&l->locked, _Q_LOCKED_VAL, 0) == _Q_LOCKED_VAL))
+        if (likely(lockval == _Q_LOCKED_VAL))
                 return;
 
+        if (unlikely(lockval != _Q_SLOW_VAL)) {
+                if (debug_locks_silent)
+                        return;
+                WARN(1, "pvqspinlock: lock %p has corrupted value 0x%x!\n", lock, atomic_read(&lock->val));
+                return;
+        }
+
         /*
          * Since the above failed to release, this must be the SLOW path.
          * Therefore start by looking up the blocked node and unhashing it.
diff --git a/kernel/module.c b/kernel/module.c
index 4d2b82e610e2..b86b7bf1be38 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -602,13 +602,16 @@ const struct kernel_symbol *find_symbol(const char *name,
 }
 EXPORT_SYMBOL_GPL(find_symbol);
 
-/* Search for module by name: must hold module_mutex. */
+/*
+ * Search for module by name: must hold module_mutex (or preempt disabled
+ * for read-only access).
+ */
 static struct module *find_module_all(const char *name, size_t len,
                                       bool even_unformed)
 {
         struct module *mod;
 
-        module_assert_mutex();
+        module_assert_mutex_or_preempt();
 
         list_for_each_entry(mod, &modules, list) {
                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
@@ -621,6 +624,7 @@ static struct module *find_module_all(const char *name, size_t len,
 
 struct module *find_module(const char *name)
 {
+        module_assert_mutex();
         return find_module_all(name, strlen(name), false);
 }
 EXPORT_SYMBOL_GPL(find_module);
diff --git a/kernel/resource.c b/kernel/resource.c
index 90552aab5f2d..fed052a1bc9f 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -504,13 +504,13 @@ int region_is_ram(resource_size_t start, unsigned long size)
 {
         struct resource *p;
         resource_size_t end = start + size - 1;
-        int flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+        unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
         const char *name = "System RAM";
         int ret = -1;
 
         read_lock(&resource_lock);
         for (p = iomem_resource.child; p ; p = p->sibling) {
-                if (end < p->start)
+                if (p->end < start)
                         continue;
 
                 if (p->start <= start && end <= p->end) {
@@ -521,7 +521,7 @@ int region_is_ram(resource_size_t start, unsigned long size)
                                 ret = 1;
                         break;
                 }
-                if (p->end < start)
+                if (end < p->start)
                         break;  /* not found */
         }
         read_unlock(&resource_lock);
diff --git a/kernel/signal.c b/kernel/signal.c
index 836df8dac6cc..0f6bbbe77b46 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2748,12 +2748,15 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
                  * Other callers might not initialize the si_lsb field,
                  * so check explicitly for the right codes here.
                  */
-                if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
+                if (from->si_signo == SIGBUS &&
+                    (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO))
                         err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
 #endif
 #ifdef SEGV_BNDERR
-                err |= __put_user(from->si_lower, &to->si_lower);
-                err |= __put_user(from->si_upper, &to->si_upper);
+                if (from->si_signo == SIGSEGV && from->si_code == SEGV_BNDERR) {
+                        err |= __put_user(from->si_lower, &to->si_lower);
+                        err |= __put_user(from->si_upper, &to->si_upper);
+                }
 #endif
                 break;
         case __SI_CHLD:
@@ -3017,7 +3020,7 @@ COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo,
                         int, sig,
                         struct compat_siginfo __user *, uinfo)
 {
-        siginfo_t info;
+        siginfo_t info = {};
         int ret = copy_siginfo_from_user32(&info, uinfo);
         if (unlikely(ret))
                 return ret;
@@ -3061,7 +3064,7 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo,
                         int, sig,
                         struct compat_siginfo __user *, uinfo)
 {
-        siginfo_t info;
+        siginfo_t info = {};
 
         if (copy_siginfo_from_user32(&info, uinfo))
                 return -EFAULT;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 02bece4a99ea..eb11011b5292 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -98,6 +98,13 @@ struct ftrace_pid {
         struct pid *pid;
 };
 
+static bool ftrace_pids_enabled(void)
+{
+        return !list_empty(&ftrace_pids);
+}
+
+static void ftrace_update_trampoline(struct ftrace_ops *ops);
+
 /*
  * ftrace_disabled is set when an anomaly is discovered.
  * ftrace_disabled is much stronger than ftrace_enabled.
@@ -109,7 +116,6 @@ static DEFINE_MUTEX(ftrace_lock);
 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
-ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 static struct ftrace_ops global_ops;
 static struct ftrace_ops control_ops;
 
@@ -183,14 +189,7 @@ static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
         if (!test_tsk_trace_trace(current))
                 return;
 
-        ftrace_pid_function(ip, parent_ip, op, regs);
-}
-
-static void set_ftrace_pid_function(ftrace_func_t func)
-{
-        /* do not set ftrace_pid_function to itself! */
-        if (func != ftrace_pid_func)
-                ftrace_pid_function = func;
+        op->saved_func(ip, parent_ip, op, regs);
 }
 
 /**
@@ -202,7 +201,6 @@ static void set_ftrace_pid_function(ftrace_func_t func)
 void clear_ftrace_function(void)
 {
         ftrace_trace_function = ftrace_stub;
-        ftrace_pid_function = ftrace_stub;
 }
 
 static void control_ops_disable_all(struct ftrace_ops *ops)
@@ -436,6 +434,12 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
         } else
                 add_ftrace_ops(&ftrace_ops_list, ops);
 
+        /* Always save the function, and reset at unregistering */
+        ops->saved_func = ops->func;
+
+        if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled())
+                ops->func = ftrace_pid_func;
+
         ftrace_update_trampoline(ops);
 
         if (ftrace_enabled)
@@ -463,15 +467,28 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
         if (ftrace_enabled)
                 update_ftrace_function();
 
+        ops->func = ops->saved_func;
+
         return 0;
 }
 
 static void ftrace_update_pid_func(void)
 {
+        bool enabled = ftrace_pids_enabled();
+        struct ftrace_ops *op;
+
         /* Only do something if we are tracing something */
         if (ftrace_trace_function == ftrace_stub)
                 return;
 
+        do_for_each_ftrace_op(op, ftrace_ops_list) {
+                if (op->flags & FTRACE_OPS_FL_PID) {
+                        op->func = enabled ? ftrace_pid_func :
+                                op->saved_func;
+                        ftrace_update_trampoline(op);
+                }
+        } while_for_each_ftrace_op(op);
+
         update_ftrace_function();
 }
 
@@ -1133,7 +1150,8 @@ static struct ftrace_ops global_ops = {
         .local_hash.filter_hash         = EMPTY_HASH,
         INIT_OPS_HASH(global_ops)
         .flags                          = FTRACE_OPS_FL_RECURSION_SAFE |
-                                          FTRACE_OPS_FL_INITIALIZED,
+                                          FTRACE_OPS_FL_INITIALIZED |
+                                          FTRACE_OPS_FL_PID,
 };
 
 /*
@@ -5023,7 +5041,9 @@ static void ftrace_update_trampoline(struct ftrace_ops *ops)
 
 static struct ftrace_ops global_ops = {
         .func                   = ftrace_stub,
-        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE |
+                                  FTRACE_OPS_FL_INITIALIZED |
+                                  FTRACE_OPS_FL_PID,
 };
 
 static int __init ftrace_nodyn_init(void)
@@ -5080,11 +5100,6 @@ void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
                 if (WARN_ON(tr->ops->func != ftrace_stub))
                         printk("ftrace ops had %pS for function\n",
                                tr->ops->func);
-                /* Only the top level instance does pid tracing */
-                if (!list_empty(&ftrace_pids)) {
-                        set_ftrace_pid_function(func);
-                        func = ftrace_pid_func;
-                }
         }
         tr->ops->func = func;
         tr->ops->private = tr;
@@ -5371,7 +5386,7 @@ static void *fpid_start(struct seq_file *m, loff_t *pos)
 {
         mutex_lock(&ftrace_lock);
 
-        if (list_empty(&ftrace_pids) && (!*pos))
+        if (!ftrace_pids_enabled() && (!*pos))
                 return (void *) 1;
 
         return seq_list_start(&ftrace_pids, *pos);
@@ -5610,6 +5625,7 @@ static struct ftrace_ops graph_ops = {
         .func                   = ftrace_stub,
         .flags                  = FTRACE_OPS_FL_RECURSION_SAFE |
                                    FTRACE_OPS_FL_INITIALIZED |
+                                   FTRACE_OPS_FL_PID |
                                    FTRACE_OPS_FL_STUB,
 #ifdef FTRACE_GRAPH_TRAMP_ADDR
         .trampoline             = FTRACE_GRAPH_TRAMP_ADDR,