Fix kernel version to only test major version

[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index a8fd844d961d06dc41a2dae3450839039fa157a6..d9e047fc3f5cdcc50a72ea68d0a7f29fa49b159b 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -24,11 +24,11 @@
 #include <string.h>
 #include <unistd.h>
 
+#include <common/common.h>
 #include <common/kernel-ctl/kernel-ctl.h>
-#include <common/lttngerr.h>
-#include <common/lttng-share.h>
 
 #include "kernel.h"
+#include "kern-modules.h"
 
 /*
  * Add context on a kernel channel.
@@ -574,15 +574,15 @@ ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
         * Init memory size counter
         * See kernel-ctl.h for explanation of this value
         */
-       nbmem = KERNEL_EVENT_LIST_SIZE;
+       nbmem = KERNEL_EVENT_INIT_LIST_SIZE;
        elist = zmalloc(sizeof(struct lttng_event) * nbmem);
 
        while ((size = fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
-               if (count > nbmem) {
+               if (count >= nbmem) {
                        DBG("Reallocating event list from %zu to %zu bytes", nbmem,
-                                       nbmem + KERNEL_EVENT_LIST_SIZE);
-                       /* Adding the default size again */
-                       nbmem += KERNEL_EVENT_LIST_SIZE;
+                                       nbmem * 2);
+                       /* Double the size */
+                       nbmem <<= 1;
                        elist = realloc(elist, nbmem * sizeof(struct lttng_event));
                        if (elist == NULL) {
                                perror("realloc list events");
@@ -607,3 +607,34 @@ error_fp:
 error:
        return -1;
 }
+
+/*
+ * Get kernel version and validate it.
+ */
+int kernel_validate_version(int tracer_fd)
+{
+       int ret;
+       struct lttng_kernel_tracer_version version;
+
+       ret = kernctl_tracer_version(tracer_fd, &version);
+       if (ret < 0) {
+               ERR("Failed at getting the lttng-modules version");
+               goto error;
+       }
+
+       /* Validate version */
+       if (version.version > KERN_MODULES_VERSION) {
+               goto error_version;
+       }
+
+       DBG2("Kernel tracer version validated (major version %d)", version.version);
+       return 0;
+
+error_version:
+       ERR("Kernel major version %d is not compatible (supporting <= %d)",
+                       version.version, KERN_MODULES_VERSION)
+       ret = -1;
+
+error:
+       return ret;
+}