[RFC patch 20/41] Linux Kernel Markers - Iterator

Mathieu Desnoyers
2009-03-05T23:28:08Z

[-- Attachment #1: linux-kernel-markers-iterator.patch --]
[-- Type: text/plain, Size: 5374 bytes --]

Add marker iterators. Useful for /proc interface (listing markers).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
include/linux/marker.h | 12 ++++++++
include/linux/module.h | 6 ++++
kernel/marker.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++
kernel/module.c | 32 ++++++++++++++++++++++
4 files changed, 120 insertions(+)

Index: linux-2.6-lttng/kernel/marker.c
===================================================================
--- linux-2.6-lttng.orig/kernel/marker.c 2009-03-05 15:21:58.000000000 -0500
+++ linux-2.6-lttng/kernel/marker.c 2009-03-05 15:45:38.000000000 -0500
@@ -898,6 +898,76 @@ EXPORT_SYMBOL_GPL(marker_get_private_dat

#ifdef CONFIG_MODULES

+/**
+ * marker_get_iter_range - Get a next marker iterator given a range.
+ * @marker: current markers (in), next marker (out)
+ * @begin: beginning of the range
+ * @end: end of the range
+ *
+ * Returns whether a next marker has been found (1) or not (0).
+ * Will return the first marker in the range if the input marker is NULL.
+ */
+int marker_get_iter_range(struct marker **marker, struct marker *begin,
+ struct marker *end)
+{
+ if (!*marker && begin != end) {
+ *marker = begin;
+ return 1;
+ }
+ if (*marker >= begin && *marker < end)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(marker_get_iter_range);
+
+static void marker_get_iter(struct marker_iter *iter)
+{
+ int found = 0;
+
+ /* Core kernel markers */
+ if (!iter->module) {
+ found = marker_get_iter_range(&iter->marker,
+ __start___markers, __stop___markers);
+ if (found)
+ goto end;
+ }
+ /* Markers in modules. */
+ found = module_get_iter_markers(iter);
+end:
+ if (!found)
+ marker_iter_reset(iter);
+}
+
+void marker_iter_start(struct marker_iter *iter)
+{
+ marker_get_iter(iter);
+}
+EXPORT_SYMBOL_GPL(marker_iter_start);
+
+void marker_iter_next(struct marker_iter *iter)
+{
+ iter->marker++;
+ /*
+ * iter->marker may be invalid because we blindly incremented it.
+ * Make sure it is valid by marshalling on the markers, getting the
+ * markers from following modules if necessary.
+ */
+ marker_get_iter(iter);
+}
+EXPORT_SYMBOL_GPL(marker_iter_next);
+
+void marker_iter_stop(struct marker_iter *iter)
+{
+}
+EXPORT_SYMBOL_GPL(marker_iter_stop);
+
+void marker_iter_reset(struct marker_iter *iter)
+{
+ iter->module = NULL;
+ iter->marker = NULL;
+}
+EXPORT_SYMBOL_GPL(marker_iter_reset);
+
int marker_module_notify(struct notifier_block *self,
unsigned long val, void *data)
{
Index: linux-2.6-lttng/kernel/module.c
===================================================================
--- linux-2.6-lttng.orig/kernel/module.c 2009-03-05 15:45:37.000000000 -0500
+++ linux-2.6-lttng/kernel/module.c 2009-03-05 15:45:38.000000000 -0500
@@ -2814,6 +2814,38 @@ void module_update_markers(void)
mod->markers + mod->num_markers);
mutex_unlock(&module_mutex);
}
+
+/*
+ * Returns 0 if current not found.
+ * Returns 1 if current found.
+ */
+int module_get_iter_markers(struct marker_iter *iter)
+{
+ struct module *iter_mod;
+ int found = 0;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(iter_mod, &modules, list) {
+ if (!iter_mod->taints) {
+ /*
+ * Sorted module list
+ */
+ if (iter_mod < iter->module)
+ continue;
+ else if (iter_mod > iter->module)
+ iter->marker = NULL;
+ found = marker_get_iter_range(&iter->marker,
+ iter_mod->markers,
+ iter_mod->markers + iter_mod->num_markers);
+ if (found) {
+ iter->module = iter_mod;
+ break;
+ }
+ }
+ }
+ mutex_unlock(&module_mutex);
+ return found;
+}
#endif

#ifdef CONFIG_TRACEPOINTS
Index: linux-2.6-lttng/include/linux/marker.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/marker.h 2009-03-05 15:21:58.000000000 -0500
+++ linux-2.6-lttng/include/linux/marker.h 2009-03-05 15:45:38.000000000 -0500
@@ -218,4 +218,16 @@ extern void *marker_get_private_data(con
*/
#define marker_synchronize_unregister() synchronize_sched()

+struct marker_iter {
+ struct module *module;
+ struct marker *marker;
+};
+
+extern void marker_iter_start(struct marker_iter *iter);
+extern void marker_iter_next(struct marker_iter *iter);
+extern void marker_iter_stop(struct marker_iter *iter);
+extern void marker_iter_reset(struct marker_iter *iter);
+extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
+ struct marker *end);
+
#endif
Index: linux-2.6-lttng/include/linux/module.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/module.h 2009-03-05 15:21:58.000000000 -0500
+++ linux-2.6-lttng/include/linux/module.h 2009-03-05 15:45:38.000000000 -0500
@@ -472,6 +472,7 @@ int unregister_module_notifier(struct no
extern void print_modules(void);

extern void module_update_markers(void);
+extern int module_get_iter_markers(struct marker_iter *iter);

extern void module_update_tracepoints(void);
extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
@@ -589,6 +590,11 @@ static inline int module_get_iter_tracep
return 0;
}

+static inline int module_get_iter_markers(struct marker_iter *iter)
+{
+ return 0;
+}
+
#endif /* CONFIG_MODULES */

struct device_driver;