Add safety assert() in session daemon

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

diff --git a/src/bin/lttng-sessiond/channel.c b/src/bin/lttng-sessiond/channel.c
index e2cdf563a6bbc42f9cf6f583b323c8c25b6217b8..e11d6d11fbcffa74d813d0722dcc7a4e65bc10aa 100644 (file)
--- a/src/bin/lttng-sessiond/channel.c
+++ b/src/bin/lttng-sessiond/channel.c
@@ -54,7 +54,8 @@ struct lttng_channel *channel_new_default_attr(int dom)
 
        switch (dom) {
        case LTTNG_DOMAIN_KERNEL:
-               chan->attr.subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
+               chan->attr.subbuf_size =
+                       default_get_kernel_channel_subbuf_size();
                chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
                chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
                break;
@@ -64,7 +65,7 @@ struct lttng_channel *channel_new_default_attr(int dom)
        case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
        case LTTNG_DOMAIN_UST_EXEC_NAME:
 #endif
-               chan->attr.subbuf_size = DEFAULT_UST_CHANNEL_SUBBUF_SIZE;
+               chan->attr.subbuf_size = default_get_ust_channel_subbuf_size();
                chan->attr.num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM;
                chan->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;
                break;
@@ -89,11 +90,17 @@ int channel_kernel_disable(struct ltt_kernel_session *ksession,
        int ret;
        struct ltt_kernel_channel *kchan;
 
+       assert(ksession);
+       assert(channel_name);
+
        kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
        if (kchan == NULL) {
                ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
                goto error;
-       } else if (kchan->enabled == 1) {
+       }
+
+       /* Only if channel is enabled disable it. */
+       if (kchan->enabled == 1) {
                ret = kernel_disable_channel(kchan);
                if (ret < 0 && ret != -EEXIST) {
                        ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL;
@@ -115,6 +122,9 @@ int channel_kernel_enable(struct ltt_kernel_session *ksession,
 {
        int ret;
 
+       assert(ksession);
+       assert(kchan);
+
        if (kchan->enabled == 0) {
                ret = kernel_enable_channel(kchan);
                if (ret < 0) {
@@ -141,6 +151,8 @@ int channel_kernel_create(struct ltt_kernel_session *ksession,
        int ret;
        struct lttng_channel *defattr = NULL;
 
+       assert(ksession);
+
        /* Creating channel attributes if needed */
        if (attr == NULL) {
                defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL);
@@ -179,6 +191,9 @@ int channel_ust_enable(struct ltt_ust_session *usess, int domain,
 {
        int ret = LTTNG_OK;
 
+       assert(usess);
+       assert(uchan);
+
        /* If already enabled, everything is OK */
        if (uchan->enabled) {
                DBG3("Channel %s already enabled. Skipping", uchan->name);
@@ -189,8 +204,16 @@ int channel_ust_enable(struct ltt_ust_session *usess, int domain,
        switch (domain) {
        case LTTNG_DOMAIN_UST:
                DBG2("Channel %s being enabled in UST global domain", uchan->name);
-               /* Enable channel for global domain */
-               ret = ust_app_enable_channel_glb(usess, uchan);
+
+               /*
+                * Enable channel for UST global domain on all applications. Ignore
+                * return value here since whatever error we got, it means that the
+                * channel was not created on one or many registered applications and
+                * we can not report this to the user yet. However, at this stage, the
+                * channel was successfully created on the session daemon side so the
+                * enable-channel command is a success.
+                */
+               (void) ust_app_create_channel_glb(usess, uchan);
                break;
 #if 0
        case LTTNG_DOMAIN_UST_PID:
@@ -202,15 +225,6 @@ int channel_ust_enable(struct ltt_ust_session *usess, int domain,
                goto error;
        }
 
-       if (ret < 0) {
-               if (ret != -EEXIST) {
-                       ret = LTTNG_ERR_UST_CHAN_ENABLE_FAIL;
-                       goto error;
-               } else {
-                       ret = LTTNG_OK;
-               }
-       }
-
        uchan->enabled = 1;
        DBG2("Channel %s enabled successfully", uchan->name);
 
@@ -229,6 +243,8 @@ int channel_ust_create(struct ltt_ust_session *usess, int domain,
        struct ltt_ust_channel *uchan = NULL;
        struct lttng_channel *defattr = NULL;
 
+       assert(usess);
+
        /* Creating channel attributes if needed */
        if (attr == NULL) {
                defattr = channel_new_default_attr(domain);
@@ -239,17 +255,24 @@ int channel_ust_create(struct ltt_ust_session *usess, int domain,
                attr = defattr;
        }
 
+       if (attr->attr.subbuf_size < DEFAULT_UST_CHANNEL_SUBBUF_SIZE) {
+               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 not report the error to the user
-        * (unlike kernel tracing).
+        * 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
+        * not report the error to the user (unlike kernel tracing).
         */
-       if (!attr->attr.subbuf_size || (attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
+       if (!attr->attr.subbuf_size ||
+                       (attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
                ret = LTTNG_ERR_INVALID;
                goto error;
        }
-       if (!attr->attr.num_subbuf || (attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
+
+       if (!attr->attr.num_subbuf ||
+                       (attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
                ret = LTTNG_ERR_INVALID;
                goto error;
        }
@@ -284,7 +307,7 @@ int channel_ust_create(struct ltt_ust_session *usess, int domain,
                goto error_free_chan;
        }
 
-       if (ret < 0 && ret != -EEXIST) {
+       if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
                ret = LTTNG_ERR_UST_CHAN_FAIL;
                goto error_free_chan;
        }
@@ -318,6 +341,9 @@ int channel_ust_disable(struct ltt_ust_session *usess, int domain,
 {
        int ret = LTTNG_OK;
 
+       assert(usess);
+       assert(uchan);
+
        /* Already disabled */
        if (uchan->enabled == 0) {
                DBG2("Channel UST %s already disabled", uchan->name);
@@ -341,7 +367,7 @@ int channel_ust_disable(struct ltt_ust_session *usess, int domain,
                goto error;
        }
 
-       if (ret < 0 && ret != -EEXIST) {
+       if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
                ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL;
                goto error;
        }