static DEFINE_MUTEX(pmus_lock);
static struct srcu_struct pmus_srcu;
static cpumask_var_t perf_online_mask;
+static struct kmem_cache *perf_event_cache;
/*
* perf event paranoia level:
perf_event__header_size(leader);
}
+static void sync_child_event(struct perf_event *child_event);
+
+static void perf_child_detach(struct perf_event *event)
+{
+ struct perf_event *parent_event = event->parent;
+
+ if (!(event->attach_state & PERF_ATTACH_CHILD))
+ return;
+
+ event->attach_state &= ~PERF_ATTACH_CHILD;
+
+ if (WARN_ON_ONCE(!parent_event))
+ return;
+
+ lockdep_assert_held(&parent_event->child_mutex);
+
+ sync_child_event(event);
+ list_del_init(&event->child_list);
+}
+
static bool is_orphaned_event(struct perf_event *event)
{
return event->state == PERF_EVENT_STATE_DEAD;
}
#define DETACH_GROUP 0x01UL
+#define DETACH_CHILD 0x02UL
/*
* Cross CPU call to remove a performance event
event_sched_out(event, cpuctx, ctx);
if (flags & DETACH_GROUP)
perf_group_detach(event);
+ if (flags & DETACH_CHILD)
+ perf_child_detach(event);
list_del_event(event, ctx);
if (!ctx->nr_events && ctx->is_active) {
lockdep_assert_held(&ctx->mutex);
- event_function_call(event, __perf_remove_from_context, (void *)flags);
-
/*
- * The above event_function_call() can NO-OP when it hits
- * TASK_TOMBSTONE. In that case we must already have been detached
- * from the context (by perf_event_exit_event()) but the grouping
- * might still be in-tact.
+ * Because of perf_event_exit_task(), perf_remove_from_context() ought
+ * to work in the face of TASK_TOMBSTONE, unlike every other
+ * event_function_call() user.
*/
- WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
- if ((flags & DETACH_GROUP) &&
- (event->attach_state & PERF_ATTACH_GROUP)) {
- /*
- * Since in that case we cannot possibly be scheduled, simply
- * detach now.
- */
- raw_spin_lock_irq(&ctx->lock);
- perf_group_detach(event);
+ raw_spin_lock_irq(&ctx->lock);
+ if (!ctx->is_active) {
+ __perf_remove_from_context(event, __get_cpu_context(ctx),
+ ctx, (void *)flags);
raw_spin_unlock_irq(&ctx->lock);
+ return;
}
+ raw_spin_unlock_irq(&ctx->lock);
+
+ event_function_call(event, __perf_remove_from_context, (void *)flags);
}
/*
static int perf_event_modify_attr(struct perf_event *event,
struct perf_event_attr *attr)
{
+ int (*func)(struct perf_event *, struct perf_event_attr *);
+ struct perf_event *child;
+ int err;
+
if (event->attr.type != attr->type)
return -EINVAL;
switch (event->attr.type) {
case PERF_TYPE_BREAKPOINT:
- return perf_event_modify_breakpoint(event, attr);
+ func = perf_event_modify_breakpoint;
+ break;
default:
/* Place holder for future additions. */
return -EOPNOTSUPP;
}
+
+ WARN_ON_ONCE(event->ctx->parent_ctx);
+
+ mutex_lock(&event->child_mutex);
+ err = func(event, attr);
+ if (err)
+ goto out;
+ list_for_each_entry(child, &event->child_list, child_list) {
+ err = func(child, attr);
+ if (err)
+ goto out;
+ }
+out:
+ mutex_unlock(&event->child_mutex);
+ return err;
}
static void ctx_sched_out(struct perf_event_context *ctx,
put_ctx(clone_ctx);
}
+static void perf_remove_from_owner(struct perf_event *event);
+static void perf_event_exit_event(struct perf_event *event,
+ struct perf_event_context *ctx);
+
+/*
+ * Removes all events from the current task that have been marked
+ * remove-on-exec, and feeds their values back to parent events.
+ */
+static void perf_event_remove_on_exec(int ctxn)
+{
+ struct perf_event_context *ctx, *clone_ctx = NULL;
+ struct perf_event *event, *next;
+ LIST_HEAD(free_list);
+ unsigned long flags;
+ bool modified = false;
+
+ ctx = perf_pin_task_context(current, ctxn);
+ if (!ctx)
+ return;
+
+ mutex_lock(&ctx->mutex);
+
+ if (WARN_ON_ONCE(ctx->task != current))
+ goto unlock;
+
+ list_for_each_entry_safe(event, next, &ctx->event_list, event_entry) {
+ if (!event->attr.remove_on_exec)
+ continue;
+
+ if (!is_kernel_event(event))
+ perf_remove_from_owner(event);
+
+ modified = true;
+
+ perf_event_exit_event(event, ctx);
+ }
+
+ raw_spin_lock_irqsave(&ctx->lock, flags);
+ if (modified)
+ clone_ctx = unclone_ctx(ctx);
+ --ctx->pin_count;
+ raw_spin_unlock_irqrestore(&ctx->lock, flags);
+
+unlock:
+ mutex_unlock(&ctx->mutex);
+
+ put_ctx(ctx);
+ if (clone_ctx)
+ put_ctx(clone_ctx);
+}
+
struct perf_read_data {
struct perf_event *event;
bool group;
if (event->ns)
put_pid_ns(event->ns);
perf_event_free_filter(event);
- kfree(event);
+ kmem_cache_free(perf_event_cache, event);
}
static void ring_buffer_attach(struct perf_event *event,
}
}
+static void perf_sigtrap(struct perf_event *event)
+{
+ struct kernel_siginfo info;
+
+ /*
+ * We'd expect this to only occur if the irq_work is delayed and either
+ * ctx->task or current has changed in the meantime. This can be the
+ * case on architectures that do not implement arch_irq_work_raise().
+ */
+ if (WARN_ON_ONCE(event->ctx->task != current))
+ return;
+
+ /*
+ * perf_pending_event() can race with the task exiting.
+ */
+ if (current->flags & PF_EXITING)
+ return;
+
+ clear_siginfo(&info);
+ info.si_signo = SIGTRAP;
+ info.si_code = TRAP_PERF;
+ info.si_errno = event->attr.type;
+ info.si_perf = event->attr.sig_data;
+ info.si_addr = (void __user *)event->pending_addr;
+ force_sig_info(&info);
+}
+
static void perf_pending_event_disable(struct perf_event *event)
{
int cpu = READ_ONCE(event->pending_disable);
if (cpu == smp_processor_id()) {
WRITE_ONCE(event->pending_disable, -1);
+
+ if (event->attr.sigtrap) {
+ perf_sigtrap(event);
+ atomic_set_release(&event->event_limit, 1); /* rearm event */
+ return;
+ }
+
perf_event_disable_local(event);
return;
}
struct perf_event_context *ctx;
int ctxn;
- rcu_read_lock();
for_each_task_context_nr(ctxn) {
- ctx = current->perf_event_ctxp[ctxn];
- if (!ctx)
- continue;
-
perf_event_enable_on_exec(ctxn);
+ perf_event_remove_on_exec(ctxn);
- perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL,
- true);
+ rcu_read_lock();
+ ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
+ if (ctx) {
+ perf_iterate_ctx(ctx, perf_event_addr_filters_exec,
+ NULL, true);
+ }
+ rcu_read_unlock();
}
- rcu_read_unlock();
}
struct remote_output {
if (events && atomic_dec_and_test(&event->event_limit)) {
ret = 1;
event->pending_kill = POLL_HUP;
+ event->pending_addr = data->addr;
perf_event_disable_inatomic(event);
}
static struct pmu *perf_init_event(struct perf_event *event)
{
+ bool extended_type = false;
int idx, type, ret;
struct pmu *pmu;
* are often aliases for PERF_TYPE_RAW.
*/
type = event->attr.type;
- if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE)
- type = PERF_TYPE_RAW;
+ if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE) {
+ type = event->attr.config >> PERF_PMU_TYPE_SHIFT;
+ if (!type) {
+ type = PERF_TYPE_RAW;
+ } else {
+ extended_type = true;
+ event->attr.config &= PERF_HW_EVENT_MASK;
+ }
+ }
again:
rcu_read_lock();
pmu = idr_find(&pmu_idr, type);
rcu_read_unlock();
if (pmu) {
+ if (event->attr.type != type && type != PERF_TYPE_RAW &&
+ !(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))
+ goto fail;
+
ret = perf_try_init_event(pmu, event);
- if (ret == -ENOENT && event->attr.type != type) {
+ if (ret == -ENOENT && event->attr.type != type && !extended_type) {
type = event->attr.type;
goto again;
}
goto unlock;
}
}
+fail:
pmu = ERR_PTR(-ENOENT);
unlock:
srcu_read_unlock(&pmus_srcu, idx);
struct perf_event *event;
struct hw_perf_event *hwc;
long err = -EINVAL;
+ int node;
if ((unsigned)cpu >= nr_cpu_ids) {
if (!task || cpu != -1)
return ERR_PTR(-EINVAL);
}
+ if (attr->sigtrap && !task) {
+ /* Requires a task: avoid signalling random tasks. */
+ return ERR_PTR(-EINVAL);
+ }
- event = kzalloc(sizeof(*event), GFP_KERNEL);
+ node = (cpu >= 0) ? cpu_to_node(cpu) : -1;
+ event = kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO,
+ node);
if (!event)
return ERR_PTR(-ENOMEM);
event->state = PERF_EVENT_STATE_INACTIVE;
+ if (event->attr.sigtrap)
+ atomic_set(&event->event_limit, 1);
+
if (task) {
event->attach_state = PERF_ATTACH_TASK;
/*
put_pid_ns(event->ns);
if (event->hw.target)
put_task_struct(event->hw.target);
- kfree(event);
+ kmem_cache_free(perf_event_cache, event);
return ERR_PTR(err);
}
(attr->sample_type & PERF_SAMPLE_WEIGHT_STRUCT))
return -EINVAL;
+ if (!attr->inherit && attr->inherit_thread)
+ return -EINVAL;
+
+ if (attr->remove_on_exec && attr->enable_on_exec)
+ return -EINVAL;
+
+ if (attr->sigtrap && !attr->remove_on_exec)
+ return -EINVAL;
+
out:
return ret;
return err;
}
- err = security_locked_down(LOCKDOWN_PERF);
- if (err && (attr.sample_type & PERF_SAMPLE_REGS_INTR))
- /* REGS_INTR can leak data, lockdown must prevent this */
- return err;
-
- err = 0;
+ /* REGS_INTR can leak data, lockdown must prevent this */
+ if (attr.sample_type & PERF_SAMPLE_REGS_INTR) {
+ err = security_locked_down(LOCKDOWN_PERF);
+ if (err)
+ return err;
+ }
/*
* In cgroup mode, the pid argument is used to pass the fd
}
EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
-static void sync_child_event(struct perf_event *child_event,
- struct task_struct *child)
+static void sync_child_event(struct perf_event *child_event)
{
struct perf_event *parent_event = child_event->parent;
u64 child_val;
- if (child_event->attr.inherit_stat)
- perf_event_read_event(child_event, child);
+ if (child_event->attr.inherit_stat) {
+ struct task_struct *task = child_event->ctx->task;
+
+ if (task && task != TASK_TOMBSTONE)
+ perf_event_read_event(child_event, task);
+ }
child_val = perf_event_count(child_event);
}
static void
-perf_event_exit_event(struct perf_event *child_event,
- struct perf_event_context *child_ctx,
- struct task_struct *child)
+perf_event_exit_event(struct perf_event *event, struct perf_event_context *ctx)
{
- struct perf_event *parent_event = child_event->parent;
+ struct perf_event *parent_event = event->parent;
+ unsigned long detach_flags = 0;
- /*
- * Do not destroy the 'original' grouping; because of the context
- * switch optimization the original events could've ended up in a
- * random child task.
- *
- * If we were to destroy the original group, all group related
- * operations would cease to function properly after this random
- * child dies.
- *
- * Do destroy all inherited groups, we don't care about those
- * and being thorough is better.
- */
- raw_spin_lock_irq(&child_ctx->lock);
- WARN_ON_ONCE(child_ctx->is_active);
+ if (parent_event) {
+ /*
+ * Do not destroy the 'original' grouping; because of the
+ * context switch optimization the original events could've
+ * ended up in a random child task.
+ *
+ * If we were to destroy the original group, all group related
+ * operations would cease to function properly after this
+ * random child dies.
+ *
+ * Do destroy all inherited groups, we don't care about those
+ * and being thorough is better.
+ */
+ detach_flags = DETACH_GROUP | DETACH_CHILD;
+ mutex_lock(&parent_event->child_mutex);
+ }
- if (parent_event)
- perf_group_detach(child_event);
- list_del_event(child_event, child_ctx);
- perf_event_set_state(child_event, PERF_EVENT_STATE_EXIT); /* is_event_hup() */
- raw_spin_unlock_irq(&child_ctx->lock);
+ perf_remove_from_context(event, detach_flags);
+
+ raw_spin_lock_irq(&ctx->lock);
+ if (event->state > PERF_EVENT_STATE_EXIT)
+ perf_event_set_state(event, PERF_EVENT_STATE_EXIT);
+ raw_spin_unlock_irq(&ctx->lock);
/*
- * Parent events are governed by their filedesc, retain them.
+ * Child events can be freed.
*/
- if (!parent_event) {
- perf_event_wakeup(child_event);
+ if (parent_event) {
+ mutex_unlock(&parent_event->child_mutex);
+ /*
+ * Kick perf_poll() for is_event_hup();
+ */
+ perf_event_wakeup(parent_event);
+ free_event(event);
+ put_event(parent_event);
return;
}
- /*
- * Child events can be cleaned up.
- */
-
- sync_child_event(child_event, child);
/*
- * Remove this event from the parent's list
- */
- WARN_ON_ONCE(parent_event->ctx->parent_ctx);
- mutex_lock(&parent_event->child_mutex);
- list_del_init(&child_event->child_list);
- mutex_unlock(&parent_event->child_mutex);
-
- /*
- * Kick perf_poll() for is_event_hup().
+ * Parent events are governed by their filedesc, retain them.
*/
- perf_event_wakeup(parent_event);
- free_event(child_event);
- put_event(parent_event);
+ perf_event_wakeup(event);
}
static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
perf_event_task(child, child_ctx, 0);
list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
- perf_event_exit_event(child_event, child_ctx, child);
+ perf_event_exit_event(child_event, child_ctx);
mutex_unlock(&child_ctx->mutex);
*/
raw_spin_lock_irqsave(&child_ctx->lock, flags);
add_event_to_ctx(child_event, child_ctx);
+ child_event->attach_state |= PERF_ATTACH_CHILD;
raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
/*
inherit_task_group(struct perf_event *event, struct task_struct *parent,
struct perf_event_context *parent_ctx,
struct task_struct *child, int ctxn,
- int *inherited_all)
+ u64 clone_flags, int *inherited_all)
{
int ret;
struct perf_event_context *child_ctx;
- if (!event->attr.inherit) {
+ if (!event->attr.inherit ||
+ (event->attr.inherit_thread && !(clone_flags & CLONE_THREAD)) ||
+ /* Do not inherit if sigtrap and signal handlers were cleared. */
+ (event->attr.sigtrap && (clone_flags & CLONE_CLEAR_SIGHAND))) {
*inherited_all = 0;
return 0;
}
/*
* Initialize the perf_event context in task_struct
*/
-static int perf_event_init_context(struct task_struct *child, int ctxn)
+static int perf_event_init_context(struct task_struct *child, int ctxn,
+ u64 clone_flags)
{
struct perf_event_context *child_ctx, *parent_ctx;
struct perf_event_context *cloned_ctx;
*/
perf_event_groups_for_each(event, &parent_ctx->pinned_groups) {
ret = inherit_task_group(event, parent, parent_ctx,
- child, ctxn, &inherited_all);
+ child, ctxn, clone_flags,
+ &inherited_all);
if (ret)
goto out_unlock;
}
perf_event_groups_for_each(event, &parent_ctx->flexible_groups) {
ret = inherit_task_group(event, parent, parent_ctx,
- child, ctxn, &inherited_all);
+ child, ctxn, clone_flags,
+ &inherited_all);
if (ret)
goto out_unlock;
}
/*
* Initialize the perf_event context in task_struct
*/
-int perf_event_init_task(struct task_struct *child)
+int perf_event_init_task(struct task_struct *child, u64 clone_flags)
{
int ctxn, ret;
INIT_LIST_HEAD(&child->perf_event_list);
for_each_task_context_nr(ctxn) {
- ret = perf_event_init_context(child, ctxn);
+ ret = perf_event_init_context(child, ctxn, clone_flags);
if (ret) {
perf_event_free_task(child);
return ret;
ret = init_hw_breakpoint();
WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
+ perf_event_cache = KMEM_CACHE(perf_event, SLAB_PANIC);
+
/*
* Build time assertion that we keep the data_head at the intended
* location. IOW, validation we got the __reserved[] size right.
projects / linux-2.6-microblaze.git / blobdiff