Fix: Return -EINVAL instead of print warning if non power of 2 size/num_subbuf

[lttng-modules.git] / lttng-context-prio.c

diff --git a/lttng-context-prio.c b/lttng-context-prio.c
index a748929a609c826ced34fb9b8c8a766e8e1b4c15..fee0dc146c1657896aa915e2a7cedc181235c3bb 100644 (file)
--- a/lttng-context-prio.c
+++ b/lttng-context-prio.c
@@ -10,17 +10,31 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
-#include "ltt-events.h"
+#include "lttng-events.h"
 #include "wrapper/ringbuffer/frontend_types.h"
 #include "wrapper/vmalloc.h"
-#include "ltt-tracer.h"
+#include "wrapper/kallsyms.h"
+#include "lttng-tracer.h"
+
+static
+int (*wrapper_task_prio_sym)(struct task_struct *t);
+
+int wrapper_task_prio_init(void)
+{
+       wrapper_task_prio_sym = (void *) kallsyms_lookup_funcptr("task_prio");
+       if (!wrapper_task_prio_sym) {
+               printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n");
+               return -EINVAL;
+       }
+       return 0;
+}
 
 static
 size_t prio_get_size(size_t offset)
 {
        size_t size = 0;
 
-       size += lib_ring_buffer_align(offset, ltt_alignof(int));
+       size += lib_ring_buffer_align(offset, lttng_alignof(int));
        size += sizeof(int);
        return size;
 }
@@ -28,13 +42,13 @@ size_t prio_get_size(size_t offset)
 static
 void prio_record(struct lttng_ctx_field *field,
                struct lib_ring_buffer_ctx *ctx,
-               struct ltt_channel *chan)
+               struct lttng_channel *chan)
 {
        int prio;
 
-       pid = p->prio - MAX_RT_PRIO;
-       lib_ring_buffer_align_ctx(ctx, ltt_alignof(pid));
-       chan->ops->event_write(ctx, &pid, sizeof(pid));
+       prio = wrapper_task_prio_sym(current);
+       lib_ring_buffer_align_ctx(ctx, lttng_alignof(prio));
+       chan->ops->event_write(ctx, &prio, sizeof(prio));
 }
 
 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx)
@@ -42,13 +56,23 @@ int lttng_add_prio_to_ctx(struct lttng_ctx **ctx)
        struct lttng_ctx_field *field;
        int ret;
 
+       if (!wrapper_task_prio_sym) {
+               ret = wrapper_task_prio_init();
+               if (ret)
+                       return ret;
+       }
+
        field = lttng_append_context(ctx);
        if (!field)
-               return ret;
+               return -ENOMEM;
+       if (lttng_find_context(*ctx, "prio")) {
+               lttng_remove_context_field(ctx, field);
+               return -EEXIST;
+       }
        field->event_field.name = "prio";
        field->event_field.type.atype = atype_integer;
        field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT;
-       field->event_field.type.u.basic.integer.alignment = ltt_alignof(int) * CHAR_BIT;
+       field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT;
        field->event_field.type.u.basic.integer.signedness = is_signed_type(int);
        field->event_field.type.u.basic.integer.reverse_byte_order = 0;
        field->event_field.type.u.basic.integer.base = 10;
@@ -62,4 +86,4 @@ EXPORT_SYMBOL_GPL(lttng_add_prio_to_ctx);
 
 MODULE_LICENSE("GPL and additional rights");
 MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");
+MODULE_DESCRIPTION("Linux Trace Toolkit Priority Context");