+++ /dev/null
-#ifndef _LIBRINGBUFFER_SHM_H
-#define _LIBRINGBUFFER_SHM_H
-
-/*
- * libringbuffer/shm.h
- *
- * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * 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
- */
-
-#include <stdint.h>
-#include <usterr-signal-safe.h>
-#include <urcu/compiler.h>
-#include "shm_types.h"
-
-/* channel_handle_create - for UST. */
-extern
-struct lttng_ust_shm_handle *channel_handle_create(void *data,
- uint64_t memory_map_size, int wakeup_fd);
-/* channel_handle_add_stream - for UST. */
-extern
-int channel_handle_add_stream(struct lttng_ust_shm_handle *handle,
- int shm_fd, int wakeup_fd, uint32_t stream_nr,
- uint64_t memory_map_size);
-unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle *handle);
-extern
-void channel_destroy(struct channel *chan, struct lttng_ust_shm_handle *handle,
- int consumer);
-
-/*
- * Pointer dereferencing. We don't trust the shm_ref, so we validate
- * both the index and offset with known boundaries.
- *
- * "shmp" and "shmp_index" guarantee that it's safe to use the pointer
- * target type, even in the occurrence of shm_ref modification by an
- * untrusted process having write access to the shm_ref. We return a
- * NULL pointer if the ranges are invalid.
- */
-static inline
-char *_shmp_offset(struct shm_object_table *table, struct shm_ref *ref,
- size_t idx, size_t elem_size)
-{
- struct shm_object *obj;
- size_t objindex, ref_offset;
-
- objindex = (size_t) ref->index;
- if (caa_unlikely(objindex >= table->allocated_len))
- return NULL;
- obj = &table->objects[objindex];
- ref_offset = (size_t) ref->offset;
- ref_offset += idx * elem_size;
- /* Check if part of the element returned would exceed the limits. */
- if (caa_unlikely(ref_offset + elem_size > obj->memory_map_size))
- return NULL;
- return &obj->memory_map[ref_offset];
-}
-
-#define shmp_index(handle, ref, index) \
- ({ \
- __typeof__((ref)._type) ____ptr_ret; \
- ____ptr_ret = (__typeof__(____ptr_ret)) _shmp_offset((handle)->table, &(ref)._ref, index, sizeof(*____ptr_ret)); \
- ____ptr_ret; \
- })
-
-#define shmp(handle, ref) shmp_index(handle, ref, 0)
-
-static inline
-void _set_shmp(struct shm_ref *ref, struct shm_ref src)
-{
- *ref = src;
-}
-
-#define set_shmp(ref, src) _set_shmp(&(ref)._ref, src)
-
-struct shm_object_table *shm_object_table_create(size_t max_nb_obj);
-struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
- size_t memory_map_size,
- enum shm_object_type type,
- const char *shm_path);
-struct shm_object *shm_object_table_append_shm(struct shm_object_table *table,
- int shm_fd, int wakeup_fd, uint32_t stream_nr,
- size_t memory_map_size);
-/* mem ownership is passed to shm_object_table_append_mem(). */
-struct shm_object *shm_object_table_append_mem(struct shm_object_table *table,
- void *mem, size_t memory_map_size, int wakeup_fd);
-void shm_object_table_destroy(struct shm_object_table *table);
-
-/*
- * zalloc_shm - allocate memory within a shm object.
- *
- * Shared memory is already zeroed by shmget.
- * *NOT* multithread-safe (should be protected by mutex).
- * Returns a -1, -1 tuple on error.
- */
-struct shm_ref zalloc_shm(struct shm_object *obj, size_t len);
-void align_shm(struct shm_object *obj, size_t align);
-
-static inline
-int shm_get_wait_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
-{
- struct shm_object_table *table = handle->table;
- struct shm_object *obj;
- size_t index;
-
- index = (size_t) ref->index;
- if (caa_unlikely(index >= table->allocated_len))
- return -EPERM;
- obj = &table->objects[index];
- return obj->wait_fd[0];
-}
-
-static inline
-int shm_get_wakeup_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
-{
- struct shm_object_table *table = handle->table;
- struct shm_object *obj;
- size_t index;
-
- index = (size_t) ref->index;
- if (caa_unlikely(index >= table->allocated_len))
- return -EPERM;
- obj = &table->objects[index];
- return obj->wait_fd[1];
-}
-
-static inline
-int shm_close_wait_fd(struct lttng_ust_shm_handle *handle,
- struct shm_ref *ref)
-{
- struct shm_object_table *table = handle->table;
- struct shm_object *obj;
- int wait_fd;
- size_t index;
- int ret;
-
- index = (size_t) ref->index;
- if (caa_unlikely(index >= table->allocated_len))
- return -EPERM;
- obj = &table->objects[index];
- wait_fd = obj->wait_fd[0];
- if (wait_fd < 0)
- return -ENOENT;
- obj->wait_fd[0] = -1;
- ret = close(wait_fd);
- if (ret) {
- ret = -errno;
- return ret;
- }
- return 0;
-}
-
-static inline
-int shm_close_wakeup_fd(struct lttng_ust_shm_handle *handle,
- struct shm_ref *ref)
-{
- struct shm_object_table *table = handle->table;
- struct shm_object *obj;
- int wakeup_fd;
- size_t index;
- int ret;
-
- index = (size_t) ref->index;
- if (caa_unlikely(index >= table->allocated_len))
- return -EPERM;
- obj = &table->objects[index];
- wakeup_fd = obj->wait_fd[1];
- if (wakeup_fd < 0)
- return -ENOENT;
- obj->wait_fd[1] = -1;
- ret = close(wakeup_fd);
- if (ret) {
- ret = -errno;
- return ret;
- }
- return 0;
-}
-
-static inline
-int shm_get_shm_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
-{
- struct shm_object_table *table = handle->table;
- struct shm_object *obj;
- size_t index;
-
- index = (size_t) ref->index;
- if (caa_unlikely(index >= table->allocated_len))
- return -EPERM;
- obj = &table->objects[index];
- return obj->shm_fd;
-}
-
-
-static inline
-int shm_get_shm_size(struct lttng_ust_shm_handle *handle, struct shm_ref *ref,
- uint64_t *size)
-{
- struct shm_object_table *table = handle->table;
- struct shm_object *obj;
- size_t index;
-
- index = (size_t) ref->index;
- if (caa_unlikely(index >= table->allocated_len))
- return -EPERM;
- obj = &table->objects[index];
- *size = obj->memory_map_size;
- return 0;
-}
-
-#endif /* _LIBRINGBUFFER_SHM_H */
projects / lttng-ust.git / blobdiff