[PATCH v3 2.6.39-rc1-tip 26/26] 26: uprobes: filter chain

[Srikar Dronamraju]

Loops through the filters callbacks of currently registered
consumers to see if any consumer is interested in tracing this task.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
 kernel/uprobes.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/kernel/uprobes.c b/kernel/uprobes.c
index c950f13..62ccb56 100644
--- a/kernel/uprobes.c
+++ b/kernel/uprobes.c
@@ -450,6 +450,23 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
 	up_read(&uprobe->consumer_rwsem);
 }
 
+static bool filter_chain(struct uprobe *uprobe, struct task_struct *t)
+{
+	struct uprobe_consumer *consumer;
+	bool ret = false;
+
+	down_read(&uprobe->consumer_rwsem);
+	for (consumer = uprobe->consumers; consumer;
+					consumer = consumer->next) {
+		if (!consumer->filter || consumer->filter(consumer, t)) {
+			ret = true;
+			break;
+		}
+	}
+	up_read(&uprobe->consumer_rwsem);
+	return ret;
+}
+
 static void add_consumer(struct uprobe *uprobe,
 				struct uprobe_consumer *consumer)
 {