Fix: incorrect close of fd 0 for syscall kernel event destroy

[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 8e960dfed8fe59786a3de2436aae3155db9851d6..2936406d84f704d1a293e95dd21f248e5c5660b3 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -208,6 +208,11 @@ int kernel_create_event(struct lttng_event *ev,
         */
        if (ret == 0 && event->event->instrumentation == LTTNG_KERNEL_SYSCALL) {
                DBG2("Kernel event syscall creation success");
+               /*
+                * We use fd == -1 to ensure that we never trigger a close of fd
+                * 0.
+                */
+               event->fd = -1;
                goto add_list;
        }
 
@@ -483,7 +488,7 @@ int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
        int ret;
        struct ltt_kernel_stream *lks;
 
-       while ((ret = kernctl_create_stream(channel->fd)) > 0) {
+       while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
                lks = trace_kernel_create_stream();
                if (lks == NULL) {
                        close(ret);