X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fring_buffer_backend.c;h=0d2cc6d0359af249e4c65e4cd4f0b9d0efbe2f0f;hb=22b22ce98477138d3e694cd66a3040d450946963;hp=c32ba982259a2099a7aa0f8bf65a7f6ecadfc1b4;hpb=a3f61e7f689a5fc60b833a773f462989dc6cc78f;p=lttng-ust.git diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c index c32ba982..0d2cc6d0 100644 --- a/libringbuffer/ring_buffer_backend.c +++ b/libringbuffer/ring_buffer_backend.c @@ -1,16 +1,29 @@ /* * 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 "lttng/core.h" +#include #include +#include "vatomic.h" #include "backend.h" #include "frontend.h" #include "smp.h" @@ -129,14 +142,6 @@ 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) { @@ -217,18 +222,18 @@ 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. */ - 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) @@ -275,7 +280,8 @@ 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); if (!shmobj) goto end; align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer)); @@ -293,7 +299,8 @@ 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); if (!shmobj) goto end; align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer)); @@ -301,6 +308,7 @@ 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) @@ -311,15 +319,6 @@ 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; @@ -334,24 +333,7 @@ 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 */ } /** @@ -399,8 +381,9 @@ 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) @@ -412,6 +395,8 @@ 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; @@ -440,8 +425,9 @@ 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,