X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;ds=sidebyside;f=libringbuffer%2Fring_buffer_backend.c;h=b65105f3a92afdfc8eceab615b73708bb045307e;hb=4bc1ccd721114691c6f0dbd65335b3c43c9f895f;hp=20d9e2d3cb81e4de7f0904b0992ae84aeb570d85;hpb=5ad63a1632792c8bc40fa5bc9f7f45f037a68032;p=lttng-ust.git diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c index 20d9e2d3..b65105f3 100644 --- a/libringbuffer/ring_buffer_backend.c +++ b/libringbuffer/ring_buffer_backend.c @@ -1,13 +1,26 @@ /* * ring_buffer_backend.c * - * Copyright (C) 2005-2010 - Mathieu Desnoyers + * Copyright (C) 2005-2012 Mathieu Desnoyers * - * Dual LGPL v2.1/GPL v2 license. + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; only + * version 2.1 of the License. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #define _GNU_SOURCE #include +#include #include #include "vatomic.h" @@ -102,7 +115,6 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf mmap_offset += subbuf_size; } } - return 0; free_array: @@ -186,6 +198,7 @@ void channel_backend_reset(struct channel_backend *chanb) * @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 + * @stream_fds: stream file descriptors. * * Returns channel pointer if successful, %NULL otherwise. * @@ -199,7 +212,8 @@ int channel_backend_init(struct channel_backend *chanb, const char *name, const struct lttng_ust_lib_ring_buffer_config *config, size_t subbuf_size, size_t num_subbuf, - struct lttng_ust_shm_handle *handle) + struct lttng_ust_shm_handle *handle, + const int *stream_fds) { struct channel *chan = caa_container_of(chanb, struct channel, backend); unsigned int i; @@ -209,18 +223,24 @@ int channel_backend_init(struct channel_backend *chanb, if (!name) return -EPERM; - if (!(subbuf_size && num_subbuf)) - return -EPERM; - /* Check that the subbuffer size is larger than a page. */ if (subbuf_size < PAGE_SIZE) 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. + */ + if (!subbuf_size || (subbuf_size & (subbuf_size - 1))) + return -EINVAL; + if (!num_subbuf || (num_subbuf & (num_subbuf - 1))) + return -EINVAL; + /* + * Overwrite mode buffers require at least 2 subbuffers per + * buffer. */ - CHAN_WARN_ON(chanb, hweight32(subbuf_size) != 1); - CHAN_WARN_ON(chanb, hweight32(num_subbuf) != 1); + if (config->mode == RING_BUFFER_OVERWRITE && num_subbuf < 2) + return -EINVAL; ret = subbuffer_id_check_index(config, num_subbuf); if (ret) @@ -267,7 +287,8 @@ int channel_backend_init(struct channel_backend *chanb, for_each_possible_cpu(i) { struct shm_object *shmobj; - shmobj = shm_object_table_append(handle->table, shmsize); + shmobj = shm_object_table_alloc(handle->table, shmsize, + SHM_OBJECT_SHM, stream_fds[i]); if (!shmobj) goto end; align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer)); @@ -285,7 +306,8 @@ int channel_backend_init(struct channel_backend *chanb, struct shm_object *shmobj; struct lttng_ust_lib_ring_buffer *buf; - shmobj = shm_object_table_append(handle->table, shmsize); + shmobj = shm_object_table_alloc(handle->table, shmsize, + SHM_OBJECT_SHM, stream_fds[0]); if (!shmobj) goto end; align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer)); @@ -366,8 +388,9 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size * @dest : destination address * @len : destination's length * - * return string's length + * Return string's length, or -EINVAL on error. * Should be protected by get_subbuf/put_subbuf. + * Destination length should be at least 1 to hold '\0'. */ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, size_t offset, void *dest, size_t len, struct lttng_ust_shm_handle *handle) @@ -379,6 +402,8 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages; unsigned long sb_bindex, id; + if (caa_unlikely(!len)) + return -EINVAL; offset &= chanb->buf_size - 1; orig_offset = offset; id = bufb->buf_rsb.id; @@ -407,8 +432,9 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si * * Return the address where a given offset is located (for read). * Should be used to get the current subbuffer header pointer. Given we know - * it's never on a page boundary, it's safe to write directly to this address, - * as long as the write is never bigger than a page size. + * it's never on a page boundary, it's safe to read/write directly + * from/to this address, as long as the read/write is never bigger than + * a page size. */ void *lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb, size_t offset,