--- /dev/null
+#ifndef _LIBCOUNTER_SHM_H
+#define _LIBCOUNTER_SHM_H
+
+/*
+ * libcounter/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 <stddef.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <usterr-signal-safe.h>
+#include <urcu/compiler.h>
+#include "shm_types.h"
+
+/* lttng_counter_handle_create - for UST. */
+extern
+struct lttng_counter_shm_handle *lttng_counter_handle_create(void *data,
+ uint64_t memory_map_size, int wakeup_fd);
+/* lttng_counter_handle_add_cpu - for UST. */
+extern
+int lttng_counter_handle_add_cpu(struct lttng_counter_shm_handle *handle,
+ int shm_fd, uint32_t cpu_nr,
+ uint64_t memory_map_size);
+unsigned int lttng_counter_handle_get_nr_cpus(struct lttng_counter_shm_handle *handle);
+
+/*
+ * 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 *_lttng_counter_shmp_offset(struct lttng_counter_shm_object_table *table,
+ struct lttng_counter_shm_ref *ref,
+ size_t idx, size_t elem_size)
+{
+ struct lttng_counter_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 lttng_counter_shmp_index(handle, ref, index) \
+ ({ \
+ __typeof__((ref)._type) ____ptr_ret; \
+ ____ptr_ret = (__typeof__(____ptr_ret)) _lttng_counter_shmp_offset((handle)->table, &(ref)._ref, index, sizeof(*____ptr_ret)); \
+ ____ptr_ret; \
+ })
+
+#define lttng_counter_shmp(handle, ref) lttng_counter_shmp_index(handle, ref, 0)
+
+static inline
+void _lttng_counter_set_shmp(struct lttng_counter_shm_ref *ref, struct lttng_counter_shm_ref src)
+{
+ *ref = src;
+}
+
+#define lttng_counter_set_shmp(ref, src) _lttng_counter_set_shmp(&(ref)._ref, src)
+
+struct lttng_counter_shm_object_table *lttng_counter_shm_object_table_create(size_t max_nb_obj);
+struct lttng_counter_shm_object *lttng_counter_shm_object_table_alloc(struct lttng_counter_shm_object_table *table,
+ size_t memory_map_size,
+ enum lttng_counter_shm_object_type type,
+ const int cpu_fd,
+ int cpu);
+struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_shm(struct lttng_counter_shm_object_table *table,
+ int shm_fd, size_t memory_map_size);
+/* mem ownership is passed to lttng_counter_shm_object_table_append_mem(). */
+struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_mem(struct lttng_counter_shm_object_table *table,
+ void *mem, size_t memory_map_size);
+void lttng_counter_shm_object_table_destroy(struct lttng_counter_shm_object_table *table, int consumer);
+
+/*
+ * lttng_counter_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 lttng_counter_shm_ref lttng_counter_zalloc_shm(struct lttng_counter_shm_object *obj, size_t len);
+void lttng_counter_align_shm(struct lttng_counter_shm_object *obj, size_t align);
+
+static inline
+int lttng_counter_shm_get_shm_fd(struct lttng_counter_shm_handle *handle, struct lttng_counter_shm_ref *ref)
+{
+ struct lttng_counter_shm_object_table *table = handle->table;
+ struct lttng_counter_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 lttng_counter_shm_get_shm_size(struct lttng_counter_shm_handle *handle, struct lttng_counter_shm_ref *ref,
+ uint64_t *size)
+{
+ struct lttng_counter_shm_object_table *table = handle->table;
+ struct lttng_counter_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 /* _LIBCOUNTER_SHM_H */
projects / deliverable / lttng-ust.git / blobdiff