08e6f56176
reason: ioctl will use the fl_lock file lock, causing context switching, further leading to the failure of g_fdcheck_lock protection Configuring NuttX and compile: $ ./tools/configure.sh -l qemu-armv8a:nsh_smp $ make Running with qemu $ qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic \ -machine virt,virtualization=on,gic-version=3 \ -net none -chardev stdio,id=con,mux=on -serial chardev:con \ -mon chardev=con,mode=readline -kernel ./nuttx Signed-off-by: hujun5 <hujun5@xiaomi.com>
130 lines
3.5 KiB
C
130 lines
3.5 KiB
C
/****************************************************************************
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* libs/libc/misc/lib_fdcheck.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/fdcheck.h>
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#include <nuttx/lib/math32.h>
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#include <nuttx/sched.h>
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#include <nuttx/spinlock.h>
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#include <sys/ioctl.h>
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#include <debug.h>
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#include <stdio.h>
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#ifdef CONFIG_FDCHECK
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define TAG_SHIFT 0
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#define TAG_BITS 8
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#define TAG_MASK ((1 << TAG_BITS) - 1)
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#define FD_SHIFT (TAG_SHIFT + TAG_BITS)
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#define FD_BITS LOG2_CEIL(OPEN_MAX)
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#define FD_MASK ((1 << FD_BITS) - 1)
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static_assert(FD_BITS <= TAG_BITS, "FD_BITS is too long");
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static spinlock_t g_fdcheck_lock = SP_UNLOCKED;
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static uint8_t g_fdcheck_tag = 0;
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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int fdcheck_restore(int val)
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{
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uint8_t tag_store;
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int fd;
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/* If val is a bare fd（0~255）, we should return it directly */
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fd = (val >> FD_SHIFT) & FD_MASK;
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if (fd == 0 || val < 0)
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{
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return val;
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}
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int ret = ioctl(fd, FIOC_GETTAG_FDCHECK, &tag_store);
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if (ret >= 0)
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{
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uint8_t tag_expect = (val >> TAG_SHIFT) & TAG_MASK;
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if (tag_expect != tag_store)
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{
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ferr("tag_expect 0x%x tag_store 0x%x\n",
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tag_expect, tag_store);
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PANIC();
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}
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}
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return fd;
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}
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int fdcheck_protect(int fd)
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{
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int protect_fd;
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uint8_t tag;
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int ret;
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if (fd <= 2)
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{
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return fd;
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}
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protect_fd = (fd & FD_MASK) << FD_SHIFT;
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ret = ioctl(fd, FIOC_GETTAG_FDCHECK, &tag);
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DEBUGASSERT(ret >= 0);
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if (tag == 0)
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{
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uint8_t fdcheck_tag;
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irqstate_t flags = spin_lock_irqsave(&g_fdcheck_lock);
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if ((++g_fdcheck_tag & TAG_MASK) == 0)
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{
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++g_fdcheck_tag;
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}
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g_fdcheck_tag &= TAG_MASK;
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protect_fd |= g_fdcheck_tag << TAG_SHIFT;
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fdcheck_tag = g_fdcheck_tag;
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spin_unlock_irqrestore(&g_fdcheck_lock, flags);
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ret = ioctl(fd, FIOC_SETTAG_FDCHECK, &fdcheck_tag);
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DEBUGASSERT(ret == 0);
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}
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else
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{
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protect_fd |= (tag & TAG_MASK) << TAG_SHIFT;
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}
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return protect_fd;
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}
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#endif
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