2014-09-23 15:11:47 +02:00
|
|
|
/****************************************************************************
|
|
|
|
* mm/shm/shmat.c
|
|
|
|
*
|
2017-10-04 23:22:27 +02:00
|
|
|
* Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved.
|
2014-09-23 15:11:47 +02:00
|
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
|
|
*
|
|
|
|
* Redistribution and use in source and binary forms, with or without
|
|
|
|
* modification, are permitted provided that the following conditions
|
|
|
|
* are met:
|
|
|
|
*
|
|
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
|
|
* notice, this list of conditions and the following disclaimer.
|
|
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
* notice, this list of conditions and the following disclaimer in
|
|
|
|
* the documentation and/or other materials provided with the
|
|
|
|
* distribution.
|
|
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
|
|
|
* used to endorse or promote products derived from this software
|
|
|
|
* without specific prior written permission.
|
|
|
|
*
|
|
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
*
|
|
|
|
****************************************************************************/
|
|
|
|
|
|
|
|
/****************************************************************************
|
|
|
|
* Included Files
|
|
|
|
****************************************************************************/
|
|
|
|
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
|
|
|
|
#include <sys/shm.h>
|
|
|
|
#include <errno.h>
|
|
|
|
|
2014-09-24 00:07:12 +02:00
|
|
|
#include <nuttx/sched.h>
|
|
|
|
#include <nuttx/arch.h>
|
|
|
|
#include <nuttx/pgalloc.h>
|
|
|
|
|
|
|
|
#include "shm/shm.h"
|
|
|
|
|
2014-09-23 15:11:47 +02:00
|
|
|
#ifdef CONFIG_MM_SHM
|
|
|
|
|
|
|
|
/****************************************************************************
|
|
|
|
* Public Functions
|
|
|
|
****************************************************************************/
|
|
|
|
|
|
|
|
/****************************************************************************
|
|
|
|
* Name: shmat
|
|
|
|
*
|
|
|
|
* Description:
|
|
|
|
* The shmat() function attaches the shared memory segment associated with
|
|
|
|
* the shared memory identifier specified by shmid to the address space of
|
|
|
|
* the calling process. The segment is attached at the address specified
|
|
|
|
* by one of the following criteria:
|
|
|
|
*
|
|
|
|
* - If shmaddr is a null pointer, the segment is attached at the first
|
|
|
|
* available address as selected by the system.
|
|
|
|
* - If shmaddr is not a null pointer and (shmflg & SHM_RND) is non-
|
|
|
|
* zero, the segment is attached at the address given by
|
|
|
|
* (shmaddr - ((uintptr_t)shmaddr % SHMLBA)).
|
|
|
|
* - If shmaddr is not a null pointer and (shmflg & SHM_RND) is 0, the
|
|
|
|
* segment is attached at the address given by shmaddr.
|
|
|
|
* - The segment is attached for reading if (shmflg & SHM_RDONLY) is
|
|
|
|
* non-zero and the calling process has read permission; otherwise, if
|
|
|
|
* it is 0 and the calling process has read and write permission, the
|
|
|
|
* segment is attached for reading and writing.
|
|
|
|
*
|
|
|
|
* Input Parameters:
|
|
|
|
* shmid - Shared memory identifier
|
|
|
|
* smaddr - Determines mapping of the shared memory region
|
|
|
|
* shmflg - See SHM_* definitions in include/sys/shm.h. Only SHM_RDONLY
|
|
|
|
* and SHM_RND are supported.
|
|
|
|
*
|
|
|
|
* Returned Value:
|
|
|
|
* Upon successful completion, shmat() will increment the value of
|
|
|
|
* shm_nattch in the data structure associated with the shared memory ID
|
2014-09-24 00:07:12 +02:00
|
|
|
* of the attached shared memory segment and return the segment's start
|
|
|
|
* address.
|
2014-09-23 15:11:47 +02:00
|
|
|
*
|
|
|
|
* Otherwise, the shared memory segment will not be attached, shmat() will
|
|
|
|
* return -1, and errno will be set to indicate the error.
|
|
|
|
*
|
|
|
|
* - EACCES
|
|
|
|
* Operation permission is denied to the calling process
|
|
|
|
* - EINVAL
|
|
|
|
* The value of shmid is not a valid shared memory identifier, the
|
|
|
|
* shmaddr is not a null pointer, and the value of
|
|
|
|
* (shmaddr -((uintptr_t)shmaddr % SHMLBA)) is an illegal address for
|
|
|
|
* attaching shared memory; or the shmaddr is not a null pointer,
|
|
|
|
* (shmflg & SHM_RND) is 0, and the value of shmaddr is an illegal
|
|
|
|
* address for attaching shared memory.
|
|
|
|
* - EMFILE
|
|
|
|
* The number of shared memory segments attached to the calling
|
|
|
|
* process would exceed the system-imposed limit.
|
|
|
|
* - ENOMEM
|
|
|
|
* The available data space is not large enough to accommodate the
|
|
|
|
* shared memory segment.
|
|
|
|
*
|
|
|
|
****************************************************************************/
|
|
|
|
|
|
|
|
FAR void *shmat(int shmid, FAR const void *shmaddr, int shmflg)
|
|
|
|
{
|
2014-09-24 00:07:12 +02:00
|
|
|
FAR struct shm_region_s *region;
|
|
|
|
FAR struct task_group_s *group;
|
|
|
|
FAR struct tcb_s *tcb;
|
|
|
|
uintptr_t vaddr;
|
|
|
|
unsigned int npages;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
/* Get the region associated with the shmid */
|
|
|
|
|
|
|
|
DEBUGASSERT(shmid >= 0 && shmid < CONFIG_ARCH_SHM_MAXREGIONS);
|
|
|
|
region = &g_shminfo.si_region[shmid];
|
|
|
|
DEBUGASSERT((region->sr_flags & SRFLAG_INUSE) != 0);
|
|
|
|
|
|
|
|
/* Get the TCB and group containing our virtual memory allocator */
|
|
|
|
|
2020-05-09 16:04:45 +02:00
|
|
|
tcb = nxsched_self();
|
2014-09-24 00:07:12 +02:00
|
|
|
DEBUGASSERT(tcb && tcb->group);
|
|
|
|
group = tcb->group;
|
|
|
|
DEBUGASSERT(group->tg_shm.gs_handle != NULL &&
|
|
|
|
group->tg_shm.gs_vaddr[shmid] == 0);
|
|
|
|
|
|
|
|
/* Get exclusive access to the region data structure */
|
|
|
|
|
2017-10-04 23:22:27 +02:00
|
|
|
ret = nxsem_wait(®ion->sr_sem);
|
2014-09-24 00:07:12 +02:00
|
|
|
if (ret < 0)
|
|
|
|
{
|
2017-10-04 23:22:27 +02:00
|
|
|
shmerr("ERROR: nxsem_wait failed: %d\n", ret);
|
|
|
|
goto errout_with_ret;
|
2014-09-24 00:07:12 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Set aside a virtual address space to span this physical region */
|
|
|
|
|
|
|
|
vaddr = (uintptr_t)gran_alloc(group->tg_shm.gs_handle,
|
|
|
|
region->sr_ds.shm_segsz);
|
|
|
|
if (vaddr == 0)
|
|
|
|
{
|
2016-06-12 17:46:23 +02:00
|
|
|
shmerr("ERROR: gran_alloc() failed\n");
|
2014-09-24 00:07:12 +02:00
|
|
|
ret = -ENOMEM;
|
|
|
|
goto errout_with_semaphore;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Convert the region size to pages */
|
|
|
|
|
2019-01-26 17:11:06 +01:00
|
|
|
npages = MM_NPAGES(region->sr_ds.shm_segsz);
|
2014-09-24 00:07:12 +02:00
|
|
|
|
|
|
|
/* Attach, i.e, map, on shared memory region to the user virtual address. */
|
|
|
|
|
|
|
|
ret = up_shmat(region->sr_pages, npages, vaddr);
|
|
|
|
if (ret < 0)
|
|
|
|
{
|
2016-06-12 17:46:23 +02:00
|
|
|
shmerr("ERROR: up_shmat() failed\n");
|
2014-09-24 00:07:12 +02:00
|
|
|
goto errout_with_vaddr;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Save the virtual address of the region. We will need that in shmat()
|
|
|
|
* to do the reverse lookup: Give the virtual address of the region to
|
|
|
|
* detach, we need to get the region table index.
|
|
|
|
*/
|
|
|
|
|
|
|
|
group->tg_shm.gs_vaddr[shmid] = vaddr;
|
|
|
|
|
|
|
|
/* Increment the count of processes attached to this region */
|
|
|
|
|
|
|
|
region->sr_ds.shm_nattch++;
|
|
|
|
|
2017-05-11 21:35:56 +02:00
|
|
|
/* Save the process ID of the last operation */
|
2014-09-24 00:07:12 +02:00
|
|
|
|
|
|
|
region->sr_ds.shm_lpid = tcb->pid;
|
|
|
|
|
|
|
|
/* Save the time of the last shmat() */
|
|
|
|
|
|
|
|
region->sr_ds.shm_atime = time(NULL);
|
|
|
|
|
|
|
|
/* Release our lock on the entry */
|
|
|
|
|
2017-10-03 23:35:24 +02:00
|
|
|
nxsem_post(®ion->sr_sem);
|
2014-09-24 00:07:12 +02:00
|
|
|
return (FAR void *)vaddr;
|
|
|
|
|
|
|
|
errout_with_vaddr:
|
|
|
|
gran_free(group->tg_shm.gs_handle, (FAR void *)vaddr,
|
|
|
|
region->sr_ds.shm_segsz);
|
2017-10-04 23:22:27 +02:00
|
|
|
|
2014-09-24 00:07:12 +02:00
|
|
|
errout_with_semaphore:
|
2017-10-03 23:35:24 +02:00
|
|
|
nxsem_post(®ion->sr_sem);
|
2017-10-04 23:22:27 +02:00
|
|
|
|
|
|
|
errout_with_ret:
|
2014-09-24 00:07:12 +02:00
|
|
|
set_errno(-ret);
|
2014-09-23 15:11:47 +02:00
|
|
|
return (FAR void *)ERROR;
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif /* CONFIG_MM_SHM */
|