lttng kprobes/ftrace integration: fix memleak

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

diff --git a/probes/lttng-kprobes.c b/probes/lttng-kprobes.c
index 9d9fb5b9a759fd6445f70478c907657736f1f082..96e7509c328bedb3211e3e3e3dfc4e4d6450f4a8 100644 (file)
--- a/probes/lttng-kprobes.c
+++ b/probes/lttng-kprobes.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include "../ltt-events.h"
 #include "../wrapper/ringbuffer/frontend_types.h"
+#include "../wrapper/vmalloc.h"
 #include "../ltt-tracer.h"
 
 static
@@ -58,6 +59,10 @@ int lttng_create_kprobe_event(const char *name, struct ltt_event *event)
        desc->nr_fields = 1;
        desc->fields = field =
                kzalloc(1 * sizeof(struct lttng_event_field), GFP_KERNEL);
+       if (!field) {
+               ret = -ENOMEM;
+               goto error_field;
+       }
        field->name = "ip";
        field->type.atype = atype_integer;
        field->type.u.basic.integer.size = sizeof(unsigned long);
@@ -70,6 +75,8 @@ int lttng_create_kprobe_event(const char *name, struct ltt_event *event)
 
        return 0;
 
+error_field:
+       kfree(desc->name);
 error_str:
        kfree(desc);
        return ret;
@@ -101,6 +108,14 @@ int lttng_kprobes_register(const char *name,
                event->u.kprobe.symbol_name;
        event->u.kprobe.kp.offset = offset;
        event->u.kprobe.kp.addr = (void *) addr;
+
+       /*
+        * Ensure the memory we just allocated don't trigger page faults.
+        * Well.. kprobes itself puts the page fault handler on the blacklist,
+        * but we can never be too careful.
+        */
+       wrapper_vmalloc_sync_all();
+
        ret = register_kprobe(&event->u.kprobe.kp);
        if (ret)
                goto register_error;
@@ -109,6 +124,7 @@ int lttng_kprobes_register(const char *name,
 register_error:
        kfree(event->u.kprobe.symbol_name);
 name_error:
+       kfree(event->desc->fields);
        kfree(event->desc->name);
        kfree(event->desc);
 error:
@@ -120,6 +136,7 @@ void lttng_kprobes_unregister(struct ltt_event *event)
 {
        unregister_kprobe(&event->u.kprobe.kp);
        kfree(event->u.kprobe.symbol_name);
+       kfree(event->desc->fields);
        kfree(event->desc->name);
        kfree(event->desc);
 }