X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fshm.h;h=ee8438587c06e7fcfcaab59f74111397b45531e6;hb=071dec4386ff4c89d8b0f92ab1a8dbf079abd50c;hp=d370375b6929cf913ed568e3e665ead996f515ec;hpb=1d4981969313da002983ca979bd85c95493f7316;p=lttng-ust.git diff --git a/libringbuffer/shm.h b/libringbuffer/shm.h index d370375b..ee843858 100644 --- a/libringbuffer/shm.h +++ b/libringbuffer/shm.h @@ -1,50 +1,75 @@ -#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" +#include "ust-helper.h" -#define SHM_MAGIC 0x54335433 -#define SHM_MAJOR 0 -#define SHM_MINOR 1 +/* channel_handle_create - for UST. */ +LTTNG_HIDDEN +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. */ +LTTNG_HIDDEN +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); +LTTNG_HIDDEN +unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle *handle); +LTTNG_HIDDEN +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(struct shm_object_table *table, struct shm_ref *ref) +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 index, offset; + size_t objindex, ref_offset; - index = (size_t) ref->index; - if (unlikely(index >= table->allocated_len)) + objindex = (size_t) ref->index; + if (caa_unlikely(objindex >= table->allocated_len)) return NULL; - obj = &table->objects[index]; - offset = (size_t) ref->offset; - if (unlikely(offset >= obj->memory_map_size)) + 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[offset]; + return &obj->memory_map[ref_offset]; } -#define shmp(handle, ref) \ +#define shmp_index(handle, ref, index) \ ({ \ __typeof__((ref)._type) ____ptr_ret; \ - ____ptr_ret = (__typeof__(____ptr_ret)) _shmp((handle)->table, &(ref)._ref); \ + ____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) { @@ -53,10 +78,24 @@ void _set_shmp(struct shm_ref *ref, struct shm_ref src) #define set_shmp(ref, src) _set_shmp(&(ref)._ref, src) +LTTNG_HIDDEN 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); +LTTNG_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); +LTTNG_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); +/* mem ownership is passed to shm_object_table_append_mem(). */ +LTTNG_HIDDEN +struct shm_object *shm_object_table_append_mem(struct shm_object_table *table, + void *mem, size_t memory_map_size, int wakeup_fd); +LTTNG_HIDDEN +void shm_object_table_destroy(struct shm_object_table *table, int consumer); /* * zalloc_shm - allocate memory within a shm object. @@ -65,7 +104,120 @@ 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. */ +LTTNG_HIDDEN struct shm_ref zalloc_shm(struct shm_object *obj, size_t len); +LTTNG_HIDDEN 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 */