Fix: Argument with 'nonnull' attribute passed null

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

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index 3a667adce53c8ccdda4f15b872c13d054907f7ed..54fe627c9a497c5be2b279b94c5c92553a086b15 100644 (file)
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -19,6 +19,7 @@
  */
 
 #define _GNU_SOURCE
+#include <unistd.h>
 #include <urcu/arch.h>
 #include <limits.h>
 
@@ -29,8 +30,6 @@
 #include "smp.h"
 #include "shm.h"
 
-#define UINT_MAX_STR_LEN 11    /* includes \0 */
-
 /**
  * lib_ring_buffer_backend_allocate - allocate a channel buffer
  * @config: ring buffer instance configuration
@@ -51,6 +50,7 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
        unsigned long subbuf_size, mmap_offset = 0;
        unsigned long num_subbuf_alloc;
        unsigned long i;
+       long page_size;
 
        subbuf_size = chanb->subbuf_size;
        num_subbuf_alloc = num_subbuf;
@@ -58,6 +58,11 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
        if (extra_reader_sb)
                num_subbuf_alloc++;
 
+       page_size = sysconf(_SC_PAGE_SIZE);
+       if (page_size <= 0) {
+               goto page_size_error;
+       }
+
        align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
        set_shmp(bufb->array, zalloc_shm(shmobj,
                        sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc));
@@ -66,9 +71,9 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
 
        /*
         * This is the largest element (the buffer pages) which needs to
-        * be aligned on PAGE_SIZE.
+        * be aligned on page size.
         */
-       align_shm(shmobj, PAGE_SIZE);
+       align_shm(shmobj, page_size);
        set_shmp(bufb->memory_map, zalloc_shm(shmobj,
                        subbuf_size * num_subbuf_alloc));
        if (caa_unlikely(!shmp(handle, bufb->memory_map)))
@@ -124,6 +129,7 @@ free_array:
 memory_map_error:
        /* bufb->array will be freed by shm teardown */
 array_error:
+page_size_error:
        return -ENOMEM;
 }
 
@@ -197,10 +203,10 @@ void channel_backend_reset(struct channel_backend *chanb)
  * @name: channel name
  * @config: client ring buffer configuration
  * @parent: dentry of parent directory, %NULL for root directory
- * @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
+ * @subbuf_size: size of sub-buffers (> page size, power of 2)
  * @num_subbuf: number of sub-buffers (power of 2)
  * @lttng_ust_shm_handle: shared memory handle
- * @shm_path: shared memory files path
+ * @stream_fds: stream file descriptors.
  *
  * Returns channel pointer if successful, %NULL otherwise.
  *
@@ -215,18 +221,23 @@ int channel_backend_init(struct channel_backend *chanb,
                         const struct lttng_ust_lib_ring_buffer_config *config,
                         size_t subbuf_size, size_t num_subbuf,
                         struct lttng_ust_shm_handle *handle,
-                        const char *shm_path)
+                        const int *stream_fds)
 {
        struct channel *chan = caa_container_of(chanb, struct channel, backend);
        unsigned int i;
        int ret;
        size_t shmsize = 0, num_subbuf_alloc;
+       long page_size;
 
        if (!name)
                return -EPERM;
 
+       page_size = sysconf(_SC_PAGE_SIZE);
+       if (page_size <= 0) {
+               return -ENOMEM;
+       }
        /* Check that the subbuffer size is larger than a page. */
-       if (subbuf_size < PAGE_SIZE)
+       if (subbuf_size < page_size)
                return -EINVAL;
 
        /*
@@ -269,7 +280,7 @@ int channel_backend_init(struct channel_backend *chanb,
        num_subbuf_alloc = num_subbuf + 1;
        shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
        shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc;
-       shmsize += offset_align(shmsize, PAGE_SIZE);
+       shmsize += offset_align(shmsize, page_size);
        shmsize += subbuf_size * num_subbuf_alloc;
        shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages));
        shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages) * num_subbuf_alloc;
@@ -288,21 +299,9 @@ int channel_backend_init(struct channel_backend *chanb,
                 */
                for_each_possible_cpu(i) {
                        struct shm_object *shmobj;
-                       char shm_buf_path[PATH_MAX];
-
-                       if (shm_path) {
-                               char cpu_nr[UINT_MAX_STR_LEN];  /* unsigned int max len */
-
-                               strncpy(shm_buf_path, shm_path, PATH_MAX);
-                               shm_buf_path[PATH_MAX - 1] = '\0';
-                               ret = snprintf(cpu_nr, UINT_MAX_STR_LEN, "%u", i);
-                               if (ret != 1)
-                                       goto end;
-                               strncat(shm_buf_path, cpu_nr,
-                                       PATH_MAX - strlen(shm_buf_path) - 1);
-                       }
+
                        shmobj = shm_object_table_alloc(handle->table, shmsize,
-                                       SHM_OBJECT_SHM, shm_path ? shm_buf_path : NULL);
+                                       SHM_OBJECT_SHM, stream_fds[i]);
                        if (!shmobj)
                                goto end;
                        align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -321,7 +320,7 @@ int channel_backend_init(struct channel_backend *chanb,
                struct lttng_ust_lib_ring_buffer *buf;
 
                shmobj = shm_object_table_alloc(handle->table, shmsize,
-                                       SHM_OBJECT_SHM, shm_path);
+                                       SHM_OBJECT_SHM, stream_fds[0]);
                if (!shmobj)
                        goto end;
                align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -375,6 +374,7 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
        ssize_t orig_len;
        struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
        unsigned long sb_bindex, id;
+       void *src;
 
        orig_len = len;
        offset &= chanb->buf_size - 1;
@@ -391,7 +391,11 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
        CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
        CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
                     && subbuffer_id_is_noref(config, id));
-       memcpy(dest, shmp_index(handle, shmp(handle, rpages->shmp)->p, offset & (chanb->subbuf_size - 1)), len);
+       src = shmp_index(handle, shmp(handle, rpages->shmp)->p,
+                       offset & (chanb->subbuf_size - 1));
+       if (caa_unlikely(!src))
+               return 0;
+       memcpy(dest, src, len);
        return orig_len;
 }
 
@@ -431,6 +435,8 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si
        CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
                     && subbuffer_id_is_noref(config, id));
        str = shmp_index(handle, shmp(handle, rpages->shmp)->p, offset & (chanb->subbuf_size - 1));
+       if (caa_unlikely(!str))
+               return -EINVAL;
        string_len = strnlen(str, len);
        if (dest && len) {
                memcpy(dest, str, string_len);