Fix: validate number of subbuffers after tweaking properties

There are properties that are tweaked by each of ust and kernel channel
create functions after a validation on the number of subbuffers for
overwrite channels. Move validation after those properties
modifications.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/bin/lttng-sessiond/channel.c b/src/bin/lttng-sessiond/channel.c
index 69498050ede41639cfc283f4288371834dfccc2d..d2a9447463b8d669eb5144741bf8fe690669151d 100644 (file)
--- a/src/bin/lttng-sessiond/channel.c
+++ b/src/bin/lttng-sessiond/channel.c
@@ -168,6 +168,19 @@ error:
        return ret;
 }
 
+static int channel_validate(struct lttng_channel *attr)
+{
+       /*
+        * The ringbuffer (both in user space and kernel) behaves badly
+        * in overwrite mode and with less than 2 subbuffers so block it
+        * right away and send back an invalid attribute error.
+        */
+       if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
+               return -1;
+       }
+       return 0;
+}
+
 /*
  * Create kernel channel of the kernel session and notify kernel thread.
  */
@@ -196,6 +209,12 @@ int channel_kernel_create(struct ltt_kernel_session *ksession,
                attr->attr.output = LTTNG_EVENT_MMAP;
        }
 
+       /* Validate common channel properties. */
+       if (channel_validate(attr) < 0) {
+               ret = LTTNG_ERR_INVALID;
+               goto error;
+       }
+
        /* Channel not found, creating it */
        ret = kernel_create_channel(ksession, attr);
        if (ret < 0) {
@@ -281,6 +300,12 @@ int channel_ust_create(struct ltt_ust_session *usess,
                attr->attr.output = LTTNG_EVENT_MMAP;
        }
 
+       /* Validate common channel properties. */
+       if (channel_validate(attr) < 0) {
+               ret = LTTNG_ERR_INVALID;
+               goto error;
+       }
+
        /*
         * Validate UST buffer size and number of buffers: must both be power of 2
         * and nonzero. We validate right here for UST, because applications will

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 5511575ec20630156c313084d1e923c42b4a0d74..03c0be68071bc5d760112f2d3d9644f80aee0e41 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1068,16 +1068,6 @@ int cmd_enable_channel(struct ltt_session *session,
                attr->attr.switch_timer_interval = 0;
        }
 
-       /*
-        * The ringbuffer (both in user space and kernel) behave badly in overwrite
-        * mode and with less than 2 subbuf so block it right away and send back an
-        * invalid attribute error.
-        */
-       if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
-               ret = LTTNG_ERR_INVALID;
-               goto error;
-       }
-
        switch (domain->type) {
        case LTTNG_DOMAIN_KERNEL:
        {