Add listing kernel event support

[lttng-tools.git] / ltt-sessiond / kernel-ctl.c

diff --git a/ltt-sessiond/kernel-ctl.c b/ltt-sessiond/kernel-ctl.c
index a4d8099f9f773b1ca485dd8cea6c6d08c635e518..f3fdc0e72423e30eabac4850571048861daaf974 100644 (file)
--- a/ltt-sessiond/kernel-ctl.c
+++ b/ltt-sessiond/kernel-ctl.c
@@ -281,3 +281,63 @@ int kernel_create_metadata_stream(struct ltt_kernel_session *session)
 error:
        return -1;
 }
+
+/*
+ *  kernel_list_events
+ *
+ *  Get the event list from the kernel tracer and return that list in the CTF
+ *  format.
+ */
+ssize_t kernel_list_events(int tracer_fd, char **list)
+{
+       int fd;
+       char *buf, *line = NULL;
+       size_t nb, nbmem, total = 0;
+       ssize_t size;
+       FILE *fp;
+
+       fd = kernctl_tracepoint_list(tracer_fd);
+       if (fd < 0) {
+               perror("kernel tracepoint list");
+               goto error;
+       }
+
+       fp = fdopen(fd, "r");
+       if (fp == NULL) {
+               perror("kernel tracepoint list fdopen");
+               goto error;
+       }
+
+       /*
+        * Init memory size counter
+        * See kernel-ctl.h for explanation of this value
+        */
+       nbmem = KERNEL_EVENT_LIST_SIZE;
+       buf = malloc(nbmem);
+
+       while ((size = getline(&line, &nb, fp)) != -1) {
+               if (total + size > nbmem) {
+                       DBG("Reallocating event list from %ld to %ld bytes", nbmem,
+                                       total + size + KERNEL_EVENT_LIST_SIZE);
+                       /* Adding the default size again */
+                       nbmem = total + size + KERNEL_EVENT_LIST_SIZE;
+                       buf = realloc(buf, nbmem);
+                       if (buf == NULL) {
+                               perror("realloc list events");
+                               goto error;
+                       }
+               }
+               memcpy(buf + total, line, size);
+               total += size;
+       }
+
+       *list = buf;
+
+       DBG("Kernel list events done");
+
+       return total;
+
+error:
+       return -1;
+}
+