116 lines
3.4 KiB
C
116 lines
3.4 KiB
C
/****************************************************************************
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* mm/shm/shmdt.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/shm.h>
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#include <assert.h>
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#include <debug.h>
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#include <errno.h>
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#include <nuttx/arch.h>
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#include <nuttx/sched.h>
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#include <nuttx/pgalloc.h>
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#include <nuttx/mm/map.h>
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#include "sched/sched.h"
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#include "shm/shm.h"
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#ifdef CONFIG_MM_SHM
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: shmdt
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*
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* Description:
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* The shmdt() function detaches the shared memory segment located at
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* the address specified by shmaddr from the address space of the calling
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* process.
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*
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* Input Parameters:
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* shmid - Shared memory identifier
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*
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* Returned Value:
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* Upon successful completion, shmdt() will decrement the value of
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* shm_nattch in the data structure associated with the shared memory ID
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* of the attached shared memory segment and return 0.
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*
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* Otherwise, the shared memory segment will not be detached, shmdt()
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* will return -1, and errno will be set to indicate the error.
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*
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****************************************************************************/
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int shmdt(FAR const void *shmaddr)
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{
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FAR struct tcb_s *tcb;
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FAR struct mm_map_entry_s *entry;
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FAR struct task_group_s *group;
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int ret;
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/* Get the TCB and group containing our virtual memory allocator */
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tcb = this_task();
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DEBUGASSERT(tcb && tcb->group);
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group = tcb->group;
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/* Get exclusive access to process' mm_map */
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ret = mm_map_lock();
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if (ret == OK)
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{
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/* Perform the reverse lookup to get the shmid corresponding to this
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* shmaddr. The mapping is matched with just shmaddr == map->vaddr.
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*/
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entry = mm_map_find(get_current_mm(), shmaddr, 1);
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if (entry && entry->vaddr == shmaddr)
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{
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DEBUGASSERT(entry->munmap);
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ret = entry->munmap(group, entry, entry->vaddr, entry->length);
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}
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else
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{
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shmerr("ERROR: No region matching this virtual address: %p\n",
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shmaddr);
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ret = -EINVAL;
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}
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mm_map_unlock();
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}
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if (ret < 0)
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{
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set_errno(-ret);
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ret = -1;
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}
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return ret;
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}
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#endif /* CONFIG_MM_SHM */
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