lttng kprobes/ftrace integration: fix memleak

[lttng-modules.git] / probes / lttng-ftrace.c

diff --git a/probes/lttng-ftrace.c b/probes/lttng-ftrace.c
index f2190370cdcdc9e2124ee4daa82520fb600c9880..061da25a1475bceda81c48facd6570d27a37bdf1 100644 (file)
--- a/probes/lttng-ftrace.c
+++ b/probes/lttng-ftrace.c
@@ -19,6 +19,7 @@
 #include "../ltt-events.h"
 #include "../wrapper/ringbuffer/frontend_types.h"
 #include "../wrapper/ftrace.h"
+#include "../wrapper/vmalloc.h"
 #include "../ltt-tracer.h"
 
 static
@@ -69,6 +70,10 @@ int lttng_create_ftrace_event(const char *name, struct ltt_event *event)
        desc->nr_fields = 2;
        desc->fields = fields =
                kzalloc(2 * sizeof(struct lttng_event_field), GFP_KERNEL);
+       if (!desc->fields) {
+               ret = -ENOMEM;
+               goto error_fields;
+       }
        fields[0].name = "ip";
        fields[0].type.atype = atype_integer;
        fields[0].type.u.basic.integer.size = sizeof(unsigned long);
@@ -91,6 +96,8 @@ int lttng_create_ftrace_event(const char *name, struct ltt_event *event)
 
        return 0;
 
+error_fields:
+       kfree(desc->name);
 error_str:
        kfree(desc);
        return ret;
@@ -115,6 +122,9 @@ int lttng_ftrace_register(const char *name,
        if (!event->u.ftrace.symbol_name)
                goto name_error;
 
+       /* Ensure the memory we just allocated don't trigger page faults */
+       wrapper_vmalloc_sync_all();
+
        ret = wrapper_register_ftrace_function_probe(event->u.ftrace.symbol_name,
                        &lttng_ftrace_ops, event);
        if (ret)
@@ -136,6 +146,7 @@ void lttng_ftrace_unregister(struct ltt_event *event)
        wrapper_unregister_ftrace_function_probe(event->u.ftrace.symbol_name,
                        &lttng_ftrace_ops, event);
        kfree(event->u.ftrace.symbol_name);
+       kfree(desc->fields);
        kfree(event->desc->name);
        kfree(event->desc);
 }
@@ -144,6 +155,7 @@ EXPORT_SYMBOL_GPL(lttng_ftrace_unregister);
 /* This module is permanent. */
 int lttng_ftrace_init(void)
 {
+       wrapper_vmalloc_sync_all();
        return 0;
 }
 module_init(lttng_ftrace_init)