1 files changed, 133 insertions, 3 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 3256e36ad251..3852e2656bb0 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -29,6 +29,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/perf_event.h>
 #include <linux/ftrace_event.h>
+#include <linux/hw_breakpoint.h>
 
 #include <asm/irq_regs.h>
 
@@ -1725,6 +1726,26 @@ static int perf_release(struct inode *inode, struct file *file)
         return 0;
 }
 
+int perf_event_release_kernel(struct perf_event *event)
+{
+        struct perf_event_context *ctx = event->ctx;
+
+        WARN_ON_ONCE(ctx->parent_ctx);
+        mutex_lock(&ctx->mutex);
+        perf_event_remove_from_context(event);
+        mutex_unlock(&ctx->mutex);
+
+        mutex_lock(&event->owner->perf_event_mutex);
+        list_del_init(&event->owner_entry);
+        mutex_unlock(&event->owner->perf_event_mutex);
+        put_task_struct(event->owner);
+
+        free_event(event);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(perf_event_release_kernel);
+
 static int perf_event_read_size(struct perf_event *event)
 {
         int entry = sizeof(u64); /* value */
@@ -1750,7 +1771,7 @@ static int perf_event_read_size(struct perf_event *event)
         return size;
 }
 
-static u64 perf_event_read_value(struct perf_event *event)
+u64 perf_event_read_value(struct perf_event *event)
 {
         struct perf_event *child;
         u64 total = 0;
@@ -1761,6 +1782,7 @@ static u64 perf_event_read_value(struct perf_event *event)
 
         return total;
 }
+EXPORT_SYMBOL_GPL(perf_event_read_value);
 
 static int perf_event_read_entry(struct perf_event *event,
                                    u64 read_format, char __user *buf)
@@ -4231,6 +4253,51 @@ static void perf_event_free_filter(struct perf_event *event)
 
 #endif /* CONFIG_EVENT_PROFILE */
 
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static void bp_perf_event_destroy(struct perf_event *event)
+{
+        release_bp_slot(event);
+}
+
+static const struct pmu *bp_perf_event_init(struct perf_event *bp)
+{
+        int err;
+        /*
+         * The breakpoint is already filled if we haven't created the counter
+         * through perf syscall
+         * FIXME: manage to get trigerred to NULL if it comes from syscalls
+         */
+        if (!bp->callback)
+                err = register_perf_hw_breakpoint(bp);
+        else
+                err = __register_perf_hw_breakpoint(bp);
+        if (err)
+                return ERR_PTR(err);
+
+        bp->destroy = bp_perf_event_destroy;
+
+        return &perf_ops_bp;
+}
+
+void perf_bp_event(struct perf_event *bp, void *regs)
+{
+        /* TODO */
+}
+#else
+static void bp_perf_event_destroy(struct perf_event *event)
+{
+}
+
+static const struct pmu *bp_perf_event_init(struct perf_event *bp)
+{
+        return NULL;
+}
+
+void perf_bp_event(struct perf_event *bp, void *regs)
+{
+}
+#endif
+
 atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
 
 static void sw_perf_event_destroy(struct perf_event *event)
@@ -4297,6 +4364,7 @@ perf_event_alloc(struct perf_event_attr *attr,
                    struct perf_event_context *ctx,
                    struct perf_event *group_leader,
                    struct perf_event *parent_event,
+                   perf_callback_t callback,
                    gfp_t gfpflags)
 {
         const struct pmu *pmu;
@@ -4339,6 +4407,11 @@ perf_event_alloc(struct perf_event_attr *attr,
 
         event->state            = PERF_EVENT_STATE_INACTIVE;
 
+        if (!callback && parent_event)
+                callback = parent_event->callback;
+        
+        event->callback = callback;
+
         if (attr->disabled)
                 event->state = PERF_EVENT_STATE_OFF;
 
@@ -4373,6 +4446,11 @@ perf_event_alloc(struct perf_event_attr *attr,
                 pmu = tp_perf_event_init(event);
                 break;
 
+        case PERF_TYPE_BREAKPOINT:
+                pmu = bp_perf_event_init(event);
+                break;
+
+
         default:
                 break;
         }
@@ -4615,7 +4693,7 @@ SYSCALL_DEFINE5(perf_event_open,
         }
 
         event = perf_event_alloc(&attr, cpu, ctx, group_leader,
-                                     NULL, GFP_KERNEL);
+                                     NULL, NULL, GFP_KERNEL);
         err = PTR_ERR(event);
         if (IS_ERR(event))
                 goto err_put_context;
@@ -4663,6 +4741,58 @@ err_put_context:
         return err;
 }
 
+/**
+ * perf_event_create_kernel_counter
+ *
+ * @attr: attributes of the counter to create
+ * @cpu: cpu in which the counter is bound
+ * @pid: task to profile
+ */
+struct perf_event *
+perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
+                                 pid_t pid, perf_callback_t callback)
+{
+        struct perf_event *event;
+        struct perf_event_context *ctx;
+        int err;
+
+        /*
+         * Get the target context (task or percpu):
+         */
+
+        ctx = find_get_context(pid, cpu);
+        if (IS_ERR(ctx))
+                return NULL;
+
+        event = perf_event_alloc(attr, cpu, ctx, NULL,
+                                     NULL, callback, GFP_KERNEL);
+        err = PTR_ERR(event);
+        if (IS_ERR(event))
+                goto err_put_context;
+
+        event->filp = NULL;
+        WARN_ON_ONCE(ctx->parent_ctx);
+        mutex_lock(&ctx->mutex);
+        perf_install_in_context(ctx, event, cpu);
+        ++ctx->generation;
+        mutex_unlock(&ctx->mutex);
+
+        event->owner = current;
+        get_task_struct(current);
+        mutex_lock(&current->perf_event_mutex);
+        list_add_tail(&event->owner_entry, &current->perf_event_list);
+        mutex_unlock(&current->perf_event_mutex);
+
+        return event;
+
+err_put_context:
+        if (err < 0)
+                put_ctx(ctx);
+
+        return NULL;
+}
+EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
+
 /*
  * inherit a event from parent task to child task:
  */
@@ -4688,7 +4818,7 @@ inherit_event(struct perf_event *parent_event,
         child_event = perf_event_alloc(&parent_event->attr,
                                            parent_event->cpu, child_ctx,
                                            group_leader, parent_event,
-                                           GFP_KERNEL);
+                                           NULL, GFP_KERNEL);
         if (IS_ERR(child_event))
                 return child_event;
         get_ctx(child_ctx);