UST check pointer/de-reference order

[lttng-ust.git] / liblttng-ust-ctl / ustctl.c

diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
index b0b5b6cc94f2997c61def90e6e30b804295abaaf..80aed04aede83b8d79894989357c514aae1126d3 100644 (file)
--- a/liblttng-ust-ctl/ustctl.c
+++ b/liblttng-ust-ctl/ustctl.c
@@ -520,6 +520,10 @@ int ustctl_tracepoint_field_list_get(int sock, int tp_field_list_handle,
        ret = ustcomm_send_app_cmd(sock, &lum, &lur);
        if (ret)
                return ret;
+       if (lur.ret_code != USTCOMM_OK) {
+               DBG("Return code: %s", ustcomm_get_readable_code(lur.ret_code));
+               return -EINVAL;
+       }
        len = ustcomm_recv_unix_sock(sock, iter, sizeof(*iter));
        if (len != sizeof(*iter)) {
                return -EINVAL;
@@ -728,7 +732,7 @@ void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle)
 struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_handle *handle,
        int cpu)
 {
-       struct channel *chan = handle->shadow_chan;
+       struct channel *chan;
        int *shm_fd, *wait_fd;
        uint64_t *memory_map_size;
        struct lttng_ust_lib_ring_buffer *buf;
@@ -737,6 +741,7 @@ struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_h
        if (!handle)
                return NULL;
 
+       chan = handle->shadow_chan;
        buf = channel_get_ring_buffer(&chan->backend.config,
                chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size);
        if (!buf)
@@ -780,11 +785,12 @@ int ustctl_get_mmap_len(struct lttng_ust_shm_handle *handle,
                unsigned long *len)
 {
        unsigned long mmap_buf_len;
-       struct channel *chan = handle->shadow_chan;
+       struct channel *chan;
 
        if (!handle || !buf || !len)
                return -EINVAL;
 
+       chan = handle->shadow_chan;
        if (chan->backend.config.output != RING_BUFFER_MMAP)
                return -EINVAL;
        mmap_buf_len = chan->backend.buf_size;
@@ -801,11 +807,12 @@ int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle,
                struct lttng_ust_lib_ring_buffer *buf,
                unsigned long *len)
 {
-       struct channel *chan = handle->shadow_chan;
+       struct channel *chan;
 
        if (!handle || !buf || !len)
                return -EINVAL;
 
+       chan = handle->shadow_chan;
        *len = chan->backend.subbuf_size;
        return 0;
 }
@@ -819,12 +826,13 @@ int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle,
 int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
                struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
 {
-       struct channel *chan = handle->shadow_chan;
+       struct channel *chan;
        unsigned long sb_bindex;
 
        if (!handle || !buf || !off)
                return -EINVAL;
 
+       chan = handle->shadow_chan;
        if (chan->backend.config.output != RING_BUFFER_MMAP)
                return -EINVAL;
        sb_bindex = subbuffer_id_get_index(&chan->backend.config,
@@ -837,11 +845,12 @@ int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
 int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle,
                struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 {
-       struct channel *chan = handle->shadow_chan;
+       struct channel *chan;
 
        if (!handle || !buf || !len)
                return -EINVAL;
 
+       chan = handle->shadow_chan;
        *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
                handle);
        return 0;
@@ -851,11 +860,12 @@ int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle,
 int ustctl_get_padded_subbuf_size(struct lttng_ust_shm_handle *handle,
                struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 {
-       struct channel *chan = handle->shadow_chan;
+       struct channel *chan;
 
        if (!handle || !buf || !len)
                return -EINVAL;
 
+       chan = handle->shadow_chan;
        *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
                handle);
        *len = PAGE_ALIGN(*len);