[PATCH] oprofile - hooks

This implements the simple hooks we need to catch unmappings, and to
make sure no stale task_struct*'s are ever used by the main oprofile
core mechanism.  If disabled, it compiles to nothing.

1 files changed, 91 insertions, 0 deletions

diff --git a/kernel/profile.c b/kernel/profile.c
new file mode 100644
index 000000000000..7ebffe971ca8
--- /dev/null
+++ b/kernel/profile.c
@@ -0,0 +1,91 @@
+/*
+ *  linux/kernel/profile.c
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/profile.h>
+#include <linux/bootmem.h>
+#include <linux/notifier.h>
+#include <linux/mm.h>
+
+/* Profile event notifications */
+ 
+#ifdef CONFIG_PROFILING
+ 
+static DECLARE_RWSEM(profile_rwsem);
+static struct notifier_block * exit_task_notifier;
+static struct notifier_block * exit_mmap_notifier;
+static struct notifier_block * exec_unmap_notifier;
+ 
+void profile_exit_task(struct task_struct * task)
+{
+	down_read(&profile_rwsem);
+	notifier_call_chain(&exit_task_notifier, 0, task);
+	up_read(&profile_rwsem);
+}
+ 
+void profile_exit_mmap(struct mm_struct * mm)
+{
+	down_read(&profile_rwsem);
+	notifier_call_chain(&exit_mmap_notifier, 0, mm);
+	up_read(&profile_rwsem);
+}
+
+void profile_exec_unmap(struct mm_struct * mm)
+{
+	down_read(&profile_rwsem);
+	notifier_call_chain(&exec_unmap_notifier, 0, mm);
+	up_read(&profile_rwsem);
+}
+
+int profile_event_register(enum profile_type type, struct notifier_block * n)
+{
+	int err = -EINVAL;
+ 
+	down_write(&profile_rwsem);
+ 
+	switch (type) {
+		case EXIT_TASK:
+			err = notifier_chain_register(&exit_task_notifier, n);
+			break;
+		case EXIT_MMAP:
+			err = notifier_chain_register(&exit_mmap_notifier, n);
+			break;
+		case EXEC_UNMAP:
+			err = notifier_chain_register(&exec_unmap_notifier, n);
+			break;
+	}
+ 
+	up_write(&profile_rwsem);
+ 
+	return err;
+}
+
+ 
+int profile_event_unregister(enum profile_type type, struct notifier_block * n)
+{
+	int err = -EINVAL;
+ 
+	down_write(&profile_rwsem);
+ 
+	switch (type) {
+		case EXIT_TASK:
+			err = notifier_chain_unregister(&exit_task_notifier, n);
+			break;
+		case EXIT_MMAP:
+			err = notifier_chain_unregister(&exit_mmap_notifier, n);
+			break;
+		case EXEC_UNMAP:
+			err = notifier_chain_unregister(&exec_unmap_notifier, n);
+			break;
+	}
+
+	up_write(&profile_rwsem);
+	return err;
+}
+
+#endif /* CONFIG_PROFILING */
+
+EXPORT_SYMBOL_GPL(profile_event_register);
+EXPORT_SYMBOL_GPL(profile_event_unregister);