X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Fshm.h;h=c3ce4ef891a998549844c09c5b5f41ceac133c4d;hb=6ba6fd60507f8e045bdc4f1be14e9d99c6a15f7f;hp=9f72a5a248657f73c3176877d2e6357930dd10db;hpb=cba4b7a3bf98faff4c905f71064f7d66b9869e79;p=lttng-ust.git diff --git a/libringbuffer/shm.h b/libringbuffer/shm.h index 9f72a5a2..c3ce4ef8 100644 --- a/libringbuffer/shm.h +++ b/libringbuffer/shm.h @@ -1,22 +1,43 @@ -#ifndef _LIBRINGBUFFER_SHM_H -#define _LIBRINGBUFFER_SHM_H - /* - * libringbuffer/shm.h - * - * Copyright 2011 (c) - Mathieu Desnoyers + * SPDX-License-Identifier: LGPL-2.1-only * - * Dual LGPL v2.1/GPL v2 license. + * Copyright (C) 2011-2012 Mathieu Desnoyers */ +#ifndef _LIBRINGBUFFER_SHM_H +#define _LIBRINGBUFFER_SHM_H + +#include #include -#include -#include "ust/core.h" +#include +#include +#include #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) + __attribute__((visibility("hidden"))); + +/* 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) + __attribute__((visibility("hidden"))); + +unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle *handle) + __attribute__((visibility("hidden"))); + /* * 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, @@ -26,23 +47,19 @@ char *_shmp_offset(struct shm_object_table *table, struct shm_ref *ref, size_t objindex, ref_offset; objindex = (size_t) ref->index; - if (unlikely(objindex >= table->allocated_len)) + 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 (unlikely(ref_offset + elem_size > obj->memory_map_size)) + 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_index(handle, ref, index) \ + ((__typeof__((ref)._type)) _shmp_offset((handle)->table, &(ref)._ref, index, sizeof(*((ref)._type)))) #define shmp(handle, ref) shmp_index(handle, ref, 0) @@ -54,10 +71,28 @@ void _set_shmp(struct shm_ref *ref, struct shm_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); -void shm_object_table_destroy(struct shm_object_table *table); -struct shm_object *shm_object_table_append(struct shm_object_table *table, - size_t memory_map_size); +struct shm_object_table *shm_object_table_create(size_t max_nb_obj) + __attribute__((visibility("hidden"))); + +struct shm_object *shm_object_table_alloc(struct shm_object_table *table, + size_t memory_map_size, + enum shm_object_type type, + const int stream_fd, + int cpu) + __attribute__((visibility("hidden"))); + +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) + __attribute__((visibility("hidden"))); + +/* 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) + __attribute__((visibility("hidden"))); + +void shm_object_table_destroy(struct shm_object_table *table, int consumer) + __attribute__((visibility("hidden"))); /* * zalloc_shm - allocate memory within a shm object. @@ -66,36 +101,121 @@ struct shm_object *shm_object_table_append(struct shm_object_table *table, * *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); +struct shm_ref zalloc_shm(struct shm_object *obj, size_t len) + __attribute__((visibility("hidden"))); + +void align_shm(struct shm_object *obj, size_t align) + __attribute__((visibility("hidden"))); static inline -int shm_get_wakeup_fd(struct shm_handle *handle, struct shm_ref *ref) +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 (unlikely(index >= table->allocated_len)) + 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_get_wait_fd(struct shm_handle *handle, struct shm_ref *ref) +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 (unlikely(index >= table->allocated_len)) + if (caa_unlikely(index >= table->allocated_len)) return -EPERM; obj = &table->objects[index]; - return obj->wait_fd[0]; + 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 */