Fix: power of 2 size check should apply to size_t type, not uint32_t

[lttng-ust.git] / libringbuffer / ring_buffer_backend.c

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index 50cb1938a63ca9bf017887c43b72873c38e81354..e949a5e292d2048f306760f329f64d668a0c30cd 100644 (file)
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -6,11 +6,12 @@
  * Dual LGPL v2.1/GPL v2 license.
  */
 
+#define _GNU_SOURCE
 #include <urcu/arch.h>
+#include <limits.h>
 
-#include "ust/core.h"
-
-#include <ust/ringbuffer-config.h>
+#include <lttng/ringbuffer-config.h>
+#include "vatomic.h"
 #include "backend.h"
 #include "frontend.h"
 #include "smp.h"
@@ -129,14 +130,6 @@ int lib_ring_buffer_backend_create(struct lttng_ust_lib_ring_buffer_backend *buf
                                                handle, shmobj);
 }
 
-void lib_ring_buffer_backend_free(struct lttng_ust_lib_ring_buffer_backend *bufb)
-{
-       /* bufb->buf_wsb will be freed by shm teardown */
-       /* bufb->array[i] will be freed by shm teardown */
-       /* bufb->array will be freed by shm teardown */
-       bufb->allocated = 0;
-}
-
 void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *bufb,
                                   struct lttng_ust_shm_handle *handle)
 {
@@ -190,7 +183,6 @@ void channel_backend_reset(struct channel_backend *chanb)
  * @chanb: channel backend
  * @name: channel name
  * @config: client ring buffer configuration
- * @priv: client private data
  * @parent: dentry of parent directory, %NULL for root directory
  * @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
  * @num_subbuf: number of sub-buffers (power of 2)
@@ -207,7 +199,7 @@ void channel_backend_reset(struct channel_backend *chanb)
 int channel_backend_init(struct channel_backend *chanb,
                         const char *name,
                         const struct lttng_ust_lib_ring_buffer_config *config,
-                        void *priv, size_t subbuf_size, size_t num_subbuf,
+                        size_t subbuf_size, size_t num_subbuf,
                         struct lttng_ust_shm_handle *handle)
 {
        struct channel *chan = caa_container_of(chanb, struct channel, backend);
@@ -226,16 +218,18 @@ int channel_backend_init(struct channel_backend *chanb,
                return -EINVAL;
 
        /*
-        * Make sure the number of subbuffers and subbuffer size are power of 2.
+        * Make sure the number of subbuffers and subbuffer size are
+        * power of 2, and nonzero.
         */
-       CHAN_WARN_ON(chanb, hweight32(subbuf_size) != 1);
-       CHAN_WARN_ON(chanb, hweight32(num_subbuf) != 1);
+       if (!subbuf_size || (subbuf_size & (subbuf_size - 1)))
+               return -EINVAL;
+       if (!num_subbuf || (num_subbuf & (num_subbuf - 1)))
+               return -EINVAL;
 
        ret = subbuffer_id_check_index(config, num_subbuf);
        if (ret)
                return ret;
 
-       chanb->priv = priv;
        chanb->buf_size = num_subbuf * subbuf_size;
        chanb->subbuf_size = subbuf_size;
        chanb->buf_size_order = get_count_order(chanb->buf_size);
@@ -303,6 +297,7 @@ int channel_backend_init(struct channel_backend *chanb,
                buf = shmp(handle, chanb->buf[0].shmp);
                if (!buf)
                        goto end;
+               set_shmp(buf->self, chanb->buf[0].shmp._ref);
                ret = lib_ring_buffer_create(buf, chanb, -1,
                                        handle, shmobj);
                if (ret)
@@ -313,15 +308,6 @@ int channel_backend_init(struct channel_backend *chanb,
        return 0;
 
 free_bufs:
-       if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-               for_each_possible_cpu(i) {
-                       struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
-                       if (!buf->backend.allocated)
-                               continue;
-                       lib_ring_buffer_free(buf, handle);
-               }
-       }
        /* We only free the buffer data upon shm teardown */
 end:
        return -ENOMEM;
@@ -336,24 +322,7 @@ end:
 void channel_backend_free(struct channel_backend *chanb,
                          struct lttng_ust_shm_handle *handle)
 {
-       const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config;
-       unsigned int i;
-
-       if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-               for_each_possible_cpu(i) {
-                       struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
-                       if (!buf->backend.allocated)
-                               continue;
-                       lib_ring_buffer_free(buf, handle);
-               }
-       } else {
-               struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[0].shmp);
-
-               CHAN_WARN_ON(chanb, !buf->backend.allocated);
-               lib_ring_buffer_free(buf, handle);
-       }
-       /* We only free the buffer data upon shm teardown */
+       /* SHM teardown takes care of everything */
 }
 
 /**