638716504d
1 store fd in the high position 2 removing the pid information , as the tag information is sufficient. Signed-off-by: hujun5 <hujun5@xiaomi.com>
126 lines
3.5 KiB
C
126 lines
3.5 KiB
C
/****************************************************************************
|
||
* libs/libc/misc/lib_fdcheck.c
|
||
*
|
||
* Licensed to the Apache Software Foundation (ASF) under one or more
|
||
* contributor license agreements. See the NOTICE file distributed with
|
||
* this work for additional information regarding copyright ownership. The
|
||
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
||
* "License"); you may not use this file except in compliance with the
|
||
* License. You may obtain a copy of the License at
|
||
*
|
||
* http://www.apache.org/licenses/LICENSE-2.0
|
||
*
|
||
* Unless required by applicable law or agreed to in writing, software
|
||
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
||
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
||
* License for the specific language governing permissions and limitations
|
||
* under the License.
|
||
*
|
||
****************************************************************************/
|
||
|
||
/****************************************************************************
|
||
* Included Files
|
||
****************************************************************************/
|
||
|
||
#include <nuttx/fdcheck.h>
|
||
#include <nuttx/lib/math32.h>
|
||
#include <nuttx/sched.h>
|
||
#include <nuttx/spinlock.h>
|
||
#include <sys/ioctl.h>
|
||
|
||
#include <debug.h>
|
||
#include <stdio.h>
|
||
|
||
#ifdef CONFIG_FDCHECK
|
||
|
||
/****************************************************************************
|
||
* Pre-processor Definitions
|
||
****************************************************************************/
|
||
|
||
#define TAG_SHIFT 0
|
||
#define TAG_BITS 8
|
||
#define TAG_MASK ((1 << TAG_BITS) - 1)
|
||
|
||
#define FD_SHIFT (TAG_SHIFT + TAG_BITS)
|
||
#define FD_BITS LOG2_CEIL(OPEN_MAX)
|
||
#define FD_MASK ((1 << FD_BITS) - 1)
|
||
|
||
static_assert(FD_BITS <= TAG_BITS, "FD_BITS is too long");
|
||
|
||
/****************************************************************************
|
||
* Private Data
|
||
****************************************************************************/
|
||
|
||
static spinlock_t g_fdcheck_lock = SP_UNLOCKED;
|
||
static uint8_t g_fdcheck_tag = 0;
|
||
|
||
/****************************************************************************
|
||
* Public Functions
|
||
****************************************************************************/
|
||
|
||
int fdcheck_restore(int val)
|
||
{
|
||
uint8_t tag_store;
|
||
int fd;
|
||
|
||
/* If val is a bare fd（0~255）, we should return it directly */
|
||
|
||
fd = (val >> FD_SHIFT) & FD_MASK;
|
||
if (fd == 0 || val < 0)
|
||
{
|
||
return val;
|
||
}
|
||
|
||
int ret = ioctl(fd, FIOC_GETTAG_FDCHECK, &tag_store);
|
||
if (ret >= 0)
|
||
{
|
||
uint8_t tag_expect = (val >> TAG_SHIFT) & TAG_MASK;
|
||
if (tag_expect != tag_store)
|
||
{
|
||
ferr("tag_expect 0x%x tag_store 0x%x\n",
|
||
tag_expect, tag_store);
|
||
PANIC();
|
||
}
|
||
}
|
||
|
||
return fd;
|
||
}
|
||
|
||
int fdcheck_protect(int fd)
|
||
{
|
||
int protect_fd;
|
||
uint8_t tag;
|
||
int ret;
|
||
|
||
if (fd <= 2)
|
||
{
|
||
return fd;
|
||
}
|
||
|
||
protect_fd = (fd & FD_MASK) << FD_SHIFT;
|
||
ret = ioctl(fd, FIOC_GETTAG_FDCHECK, &tag);
|
||
DEBUGASSERT(ret >= 0);
|
||
if (tag == 0)
|
||
{
|
||
irqstate_t flags = spin_lock_irqsave(&g_fdcheck_lock);
|
||
if ((++g_fdcheck_tag & TAG_MASK) == 0)
|
||
{
|
||
++g_fdcheck_tag;
|
||
}
|
||
|
||
g_fdcheck_tag &= TAG_MASK;
|
||
protect_fd |= g_fdcheck_tag << TAG_SHIFT;
|
||
ret = ioctl(fd, FIOC_SETTAG_FDCHECK, &g_fdcheck_tag);
|
||
DEBUGASSERT(ret == 0);
|
||
spin_unlock_irqrestore(&g_fdcheck_lock, flags);
|
||
}
|
||
else
|
||
{
|
||
protect_fd |= (tag & TAG_MASK) << TAG_SHIFT;
|
||
}
|
||
|
||
return protect_fd;
|
||
}
|
||
|
||
#endif
|