86fab49c46
NULL inode passed to files_allocate doesn't mark file struct in the allocated state, so other threads which invovle in file allocation (e.g. open or dup) may allocate the same file struct again. Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com> Change-Id: I53ff876eae3c7a1e311e7f671686b73a4b4ef891
112 lines
3.2 KiB
C
112 lines
3.2 KiB
C
/****************************************************************************
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* fs/vfs/fs_dupfd.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 <sched.h>
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#include <errno.h>
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#include <assert.h>
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#include <nuttx/fs/fs.h>
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#include "inode/inode.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: file_dup
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*
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* Description:
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* Equivalent to the non-standard fs_dupfd() function except that it
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* accepts a struct file instance instead of a file descriptor.
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*
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* Returned Value:
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* The new file descriptor is returned on success; a negated errno value
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* is returned on any failure.
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*
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****************************************************************************/
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int file_dup(FAR struct file *filep, int minfd)
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{
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struct file filep2;
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int fd2;
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int ret;
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/* Let file_dup2() do the real work */
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memset(&filep2, 0, sizeof(filep2));
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ret = file_dup2(filep, &filep2);
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if (ret < 0)
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{
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return ret;
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}
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/* Then allocate a new file descriptor for the inode */
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fd2 = files_allocate(filep2.f_inode, filep2.f_oflags,
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filep2.f_pos, filep2.f_priv, minfd);
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if (fd2 < 0)
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{
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file_close(&filep2);
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return fd2;
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}
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return fd2;
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}
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/****************************************************************************
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* Name: fs_dupfd
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*
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* Description:
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* Clone a file descriptor 'fd' to an arbitrary descriptor number (any
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* value greater than or equal to 'minfd').
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*
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* Returned Value:
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* The new file descriptor is returned on success; a negated errno value
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* is returned on any failure.
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*
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****************************************************************************/
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int fs_dupfd(int fd, int minfd)
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{
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FAR struct file *filep;
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int ret;
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/* Get the file structure corresponding to the file descriptor. */
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ret = fs_getfilep(fd, &filep);
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if (ret < 0)
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{
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return ret;
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}
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DEBUGASSERT(filep != NULL);
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/* Let file_dup() do the real work */
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return file_dup(filep, minfd);
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}
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