db4840564d
When a7 curl calls dns_query via usrsock, it will wait a usrsock response with the dns lock held. If a7 rptun recv a dns_addnameserver event from another core at this time, rptun waits the lock held by curl in callback. Then curl will never get its usrsock response with rptun blocked, so the deadlock occurs. This change will break lock when do usrsock request. Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
99 lines
3.0 KiB
C
99 lines
3.0 KiB
C
/****************************************************************************
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* libs/libc/netdb/lib_dnsinit.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 <string.h>
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#include <errno.h>
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#include <assert.h>
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#include <arpa/inet.h>
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#include <nuttx/sched.h>
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#include <nuttx/mutex.h>
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#include "netdb/lib_dns.h"
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/* Protects DNS cache, nameserver list and notify list. */
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static rmutex_t g_dns_lock = NXRMUTEX_INITIALIZER;
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: dns_lock
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*
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* Description:
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* Take the DNS lock, ignoring errors due to the receipt of signals.
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*
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****************************************************************************/
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void dns_lock(void)
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{
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nxrmutex_lock(&g_dns_lock);
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}
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/****************************************************************************
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* Name: dns_unlock
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*
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* Description:
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* Release the DNS lock
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*
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****************************************************************************/
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void dns_unlock(void)
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{
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nxrmutex_unlock(&g_dns_lock);
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}
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/****************************************************************************
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* Name: dns_breaklock
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*
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* Description:
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* Break the DNS lock
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****************************************************************************/
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void dns_breaklock(FAR unsigned int *count)
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{
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nxrmutex_breaklock(&g_dns_lock, count);
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}
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/****************************************************************************
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* Name: dns_restorelock
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*
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* Description:
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* Restore the DNS lock
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*
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****************************************************************************/
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void dns_restorelock(unsigned int count)
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{
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nxrmutex_restorelock(&g_dns_lock, count);
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}
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