From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 kernel/gcov/base.c | 161 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 kernel/gcov/base.c

(limited to 'kernel/gcov/base.c')

diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c
new file mode 100644
index 000000000..a744098e4
--- /dev/null
+++ b/kernel/gcov/base.c
@@ -0,0 +1,161 @@
+/*
+ *  This code maintains a list of active profiling data structures.
+ *
+ *    Copyright IBM Corp. 2009
+ *    Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
+ *
+ *    Uses gcc-internal data definitions.
+ *    Based on the gcov-kernel patch by:
+ *		 Hubertus Franke <frankeh@us.ibm.com>
+ *		 Nigel Hinds <nhinds@us.ibm.com>
+ *		 Rajan Ravindran <rajancr@us.ibm.com>
+ *		 Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
+ *		 Paul Larson
+ */
+
+#define pr_fmt(fmt)	"gcov: " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include "gcov.h"
+
+static int gcov_events_enabled;
+static DEFINE_MUTEX(gcov_lock);
+
+/*
+ * __gcov_init is called by gcc-generated constructor code for each object
+ * file compiled with -fprofile-arcs.
+ */
+void __gcov_init(struct gcov_info *info)
+{
+	static unsigned int gcov_version;
+
+	mutex_lock(&gcov_lock);
+	if (gcov_version == 0) {
+		gcov_version = gcov_info_version(info);
+		/*
+		 * Printing gcc's version magic may prove useful for debugging
+		 * incompatibility reports.
+		 */
+		pr_info("version magic: 0x%x\n", gcov_version);
+	}
+	/*
+	 * Add new profiling data structure to list and inform event
+	 * listener.
+	 */
+	gcov_info_link(info);
+	if (gcov_events_enabled)
+		gcov_event(GCOV_ADD, info);
+	mutex_unlock(&gcov_lock);
+}
+EXPORT_SYMBOL(__gcov_init);
+
+/*
+ * These functions may be referenced by gcc-generated profiling code but serve
+ * no function for kernel profiling.
+ */
+void __gcov_flush(void)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_flush);
+
+void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_add);
+
+void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_single);
+
+void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_delta);
+
+void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_ior);
+
+void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_time_profile);
+
+/**
+ * gcov_enable_events - enable event reporting through gcov_event()
+ *
+ * Turn on reporting of profiling data load/unload-events through the
+ * gcov_event() callback. Also replay all previous events once. This function
+ * is needed because some events are potentially generated too early for the
+ * callback implementation to handle them initially.
+ */
+void gcov_enable_events(void)
+{
+	struct gcov_info *info = NULL;
+
+	mutex_lock(&gcov_lock);
+	gcov_events_enabled = 1;
+
+	/* Perform event callback for previously registered entries. */
+	while ((info = gcov_info_next(info))) {
+		gcov_event(GCOV_ADD, info);
+		cond_resched();
+	}
+
+	mutex_unlock(&gcov_lock);
+}
+
+#ifdef CONFIG_MODULES
+static inline int within(void *addr, void *start, unsigned long size)
+{
+	return ((addr >= start) && (addr < start + size));
+}
+
+/* Update list and generate events when modules are unloaded. */
+static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
+				void *data)
+{
+	struct module *mod = data;
+	struct gcov_info *info = NULL;
+	struct gcov_info *prev = NULL;
+
+	if (event != MODULE_STATE_GOING)
+		return NOTIFY_OK;
+	mutex_lock(&gcov_lock);
+
+	/* Remove entries located in module from linked list. */
+	while ((info = gcov_info_next(info))) {
+		if (within(info, mod->module_core, mod->core_size)) {
+			gcov_info_unlink(prev, info);
+			if (gcov_events_enabled)
+				gcov_event(GCOV_REMOVE, info);
+		} else
+			prev = info;
+	}
+
+	mutex_unlock(&gcov_lock);
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block gcov_nb = {
+	.notifier_call	= gcov_module_notifier,
+};
+
+static int __init gcov_init(void)
+{
+	return register_module_notifier(&gcov_nb);
+}
+device_initcall(gcov_init);
+#endif /* CONFIG_MODULES */
-- 
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