X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fperf_counter.c;h=b0b20a07f3942422f614a4d0f429a23d19db396e;hb=43b51ead3f752a3935116e5b1a94254b8573734f;hp=00231054041726ad07a6da60b5a9f27a85921ea6;hpb=3a43ce68ae1758fa6a839386025ef45acb6baa22;p=pandora-kernel.git

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 002310540417..b0b20a07f394 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -2646,7 +2646,6 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 		u64 counter;
 	} group_entry;
 	struct perf_callchain_entry *callchain = NULL;
-	struct perf_raw_record *raw = NULL;
 	int callchain_size = 0;
 	u64 time;
 	struct {
@@ -2716,9 +2715,15 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 	}
 
 	if (sample_type & PERF_SAMPLE_RAW) {
-		raw = data->raw;
-		if (raw)
-			header.size += raw->size;
+		int size = sizeof(u32);
+
+		if (data->raw)
+			size += data->raw->size;
+		else
+			size += sizeof(u32);
+
+		WARN_ON_ONCE(size & (sizeof(u64)-1));
+		header.size += size;
 	}
 
 	ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
@@ -2784,8 +2789,21 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 		}
 	}
 
-	if ((sample_type & PERF_SAMPLE_RAW) && raw)
-		perf_output_copy(&handle, raw->data, raw->size);
+	if (sample_type & PERF_SAMPLE_RAW) {
+		if (data->raw) {
+			perf_output_put(&handle, data->raw->size);
+			perf_output_copy(&handle, data->raw->data, data->raw->size);
+		} else {
+			struct {
+				u32	size;
+				u32	data;
+			} raw = {
+				.size = sizeof(u32),
+				.data = 0,
+			};
+			perf_output_put(&handle, raw);
+		}
+	}
 
 	perf_output_end(&handle);
 }
@@ -2850,7 +2868,8 @@ perf_counter_read_event(struct perf_counter *counter,
  */
 
 struct perf_task_event {
-	struct task_struct	*task;
+	struct task_struct		*task;
+	struct perf_counter_context	*task_ctx;
 
 	struct {
 		struct perf_event_header	header;
@@ -2910,24 +2929,23 @@ static void perf_counter_task_ctx(struct perf_counter_context *ctx,
 static void perf_counter_task_event(struct perf_task_event *task_event)
 {
 	struct perf_cpu_context *cpuctx;
-	struct perf_counter_context *ctx;
+	struct perf_counter_context *ctx = task_event->task_ctx;
 
 	cpuctx = &get_cpu_var(perf_cpu_context);
 	perf_counter_task_ctx(&cpuctx->ctx, task_event);
 	put_cpu_var(perf_cpu_context);
 
 	rcu_read_lock();
-	/*
-	 * doesn't really matter which of the child contexts the
-	 * events ends up in.
-	 */
-	ctx = rcu_dereference(current->perf_counter_ctxp);
+	if (!ctx)
+		ctx = rcu_dereference(task_event->task->perf_counter_ctxp);
 	if (ctx)
 		perf_counter_task_ctx(ctx, task_event);
 	rcu_read_unlock();
 }
 
-static void perf_counter_task(struct task_struct *task, int new)
+static void perf_counter_task(struct task_struct *task,
+			      struct perf_counter_context *task_ctx,
+			      int new)
 {
 	struct perf_task_event task_event;
 
@@ -2937,8 +2955,9 @@ static void perf_counter_task(struct task_struct *task, int new)
 		return;
 
 	task_event = (struct perf_task_event){
-		.task	= task,
-		.event  = {
+		.task	  = task,
+		.task_ctx = task_ctx,
+		.event    = {
 			.header = {
 				.type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
 				.misc = 0,
@@ -2956,7 +2975,7 @@ static void perf_counter_task(struct task_struct *task, int new)
 
 void perf_counter_fork(struct task_struct *task)
 {
-	perf_counter_task(task, 1);
+	perf_counter_task(task, NULL, 1);
 }
 
 /*
@@ -3768,6 +3787,14 @@ static void tp_perf_counter_destroy(struct perf_counter *counter)
 
 static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
 {
+	/*
+	 * Raw tracepoint data is a severe data leak, only allow root to
+	 * have these.
+	 */
+	if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
+			!capable(CAP_SYS_ADMIN))
+		return ERR_PTR(-EPERM);
+
 	if (ftrace_profile_enable(counter->attr.config))
 		return NULL;
 
@@ -4310,7 +4337,7 @@ void perf_counter_exit_task(struct task_struct *child)
 	unsigned long flags;
 
 	if (likely(!child->perf_counter_ctxp)) {
-		perf_counter_task(child, 0);
+		perf_counter_task(child, NULL, 0);
 		return;
 	}
 
@@ -4330,6 +4357,7 @@ void perf_counter_exit_task(struct task_struct *child)
 	 * incremented the context's refcount before we do put_ctx below.
 	 */
 	spin_lock(&child_ctx->lock);
+	child->perf_counter_ctxp = NULL;
 	/*
 	 * If this context is a clone; unclone it so it can't get
 	 * swapped to another process while we're removing all
@@ -4343,9 +4371,7 @@ void perf_counter_exit_task(struct task_struct *child)
 	 * won't get any samples after PERF_EVENT_EXIT. We can however still
 	 * get a few PERF_EVENT_READ events.
 	 */
-	perf_counter_task(child, 0);
-
-	child->perf_counter_ctxp = NULL;
+	perf_counter_task(child, child_ctx, 0);
 
 	/*
 	 * We can recurse on the same lock type through: