Fix: enable event loglevel match function

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

diff --git a/src/bin/lttng-sessiond/event.c b/src/bin/lttng-sessiond/event.c
index ac4b0b4a365f7f493973f7389cd58f241c8292ae..24dd292a4e3fdd5f86e48cf0ae11762938766694 100644 (file)
--- a/src/bin/lttng-sessiond/event.c
+++ b/src/bin/lttng-sessiond/event.c
@@ -45,6 +45,32 @@ static void init_syscalls_kernel_event(struct lttng_event *event)
        event->type = LTTNG_EVENT_SYSCALL;
 }
 
+/*
+ * Return 1 if loglevels match or 0 on failure.
+ */
+static int loglevel_match(struct ltt_ust_event *uevent,
+               enum lttng_ust_loglevel_type log_type, int loglevel)
+{
+       /*
+        * For the loglevel type ALL, the loglevel is set to -1 but the event
+        * received by the session daemon is 0 which does not match the negative
+        * value in the existing event.
+        */
+       if (log_type == LTTNG_UST_LOGLEVEL_ALL) {
+               loglevel = -1;
+       }
+
+       if (uevent == NULL || uevent->attr.loglevel_type != log_type ||
+                       uevent->attr.loglevel != loglevel) {
+               goto no_match;
+       }
+
+       return 1;
+
+no_match:
+       return 0;
+}
+
 /*
  * Disable kernel tracepoint event for a channel from the kernel session.
  */
@@ -134,10 +160,16 @@ int event_kernel_enable_tracepoint(struct ltt_kernel_session *ksession,
        if (kevent == NULL) {
                ret = kernel_create_event(event, kchan);
                if (ret < 0) {
-                       if (ret == -EEXIST) {
+                       switch (-ret) {
+                       case EEXIST:
                                ret = LTTCOMM_KERN_EVENT_EXIST;
-                       } else {
+                               break;
+                       case ENOSYS:
+                               ret = LTTCOMM_KERN_EVENT_ENOSYS;
+                               break;
+                       default:
                                ret = LTTCOMM_KERN_ENABLE_FAIL;
+                               break;
                        }
                        goto end;
                }
@@ -239,15 +271,26 @@ end:
 int event_kernel_enable_all(struct ltt_kernel_session *ksession,
                struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 {
-       int ret;
+       int tp_ret;
 
-       ret = event_kernel_enable_all_tracepoints(ksession, kchan, kernel_tracer_fd);
-       if (ret != LTTCOMM_OK) {
+       tp_ret = event_kernel_enable_all_tracepoints(ksession, kchan, kernel_tracer_fd);
+       if (tp_ret != LTTCOMM_OK) {
                goto end;
        }
-       ret = event_kernel_enable_all_syscalls(ksession, kchan, kernel_tracer_fd);
+
+       /*
+        * Reaching this code path means that all tracepoints were enabled without
+        * errors so we ignore the error value of syscalls.
+        *
+        * At the moment, failing to enable syscalls on "lttng enable-event -a -k"
+        * is not considered an error that need to be returned to the client since
+        * tracepoints did not fail. Future work will allow us to send back
+        * multiple errors to the client in one API call.
+        */
+       (void) event_kernel_enable_all_syscalls(ksession, kchan, kernel_tracer_fd);
+
 end:
-       return ret;
+       return tp_ret;
 }
 
 /*
@@ -262,8 +305,7 @@ end:
 int event_ust_enable_all_tracepoints(struct ltt_ust_session *usess, int domain,
                struct ltt_ust_channel *uchan)
 {
-       int ret, i;
-       size_t size;
+       int ret, i, size;
        struct lttng_ht_iter iter;
        struct ltt_ust_event *uevent = NULL;
        struct lttng_event *events = NULL;
@@ -379,8 +421,23 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess, int domain,
                to_create = 1;
        }
 
+       /* Check loglevels */
+       ret = loglevel_match(uevent, event->loglevel_type, event->loglevel);
+       if (ret == 0) {
+               /*
+                * No match meaning that the user tried to enable a known event but
+                * with a different loglevel.
+                */
+               DBG("Enable event %s does not match existing event %s with loglevel "
+                               "respectively of %d and %d", event->name, uevent->attr.name,
+                               uevent->attr.loglevel, event->loglevel);
+               ret = LTTCOMM_EVENT_EXIST_LOGLEVEL;
+               goto error;
+       }
+
        if (uevent->enabled) {
                /* It's already enabled so everything is OK */
+               ret = LTTCOMM_OK;
                goto end;
        }
 
@@ -504,8 +561,7 @@ error:
 int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess, int domain,
                struct ltt_ust_channel *uchan)
 {
-       int ret, i;
-       size_t size;
+       int ret, i, size;
        struct lttng_ht_iter iter;
        struct ltt_ust_event *uevent = NULL;
        struct lttng_event *events = NULL;