nuttx/drivers/syslog/syslog_flush.c
Xiang Xiao 972033a61f syslog: Check sc_flush in't NULL before invocation
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2020-04-27 13:48:56 +08:00

101 lines
3.7 KiB
C

/****************************************************************************
* drivers/syslog/syslog_flush.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* 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 <stdbool.h>
#include <assert.h>
#include <nuttx/syslog/syslog.h>
#include "syslog.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: syslog_flush
*
* Description:
* This is called by system crash-handling logic. It must flush any
* buffered data to the SYSLOG device.
*
* Interrupts are disabled at the time of the crash and this logic must
* perform the flush using low-level, non-interrupt driven logic.
*
* REVISIT: There is an implementation problem in that if a character
* driver is the underlying device, then there is no mechanism to flush
* the data buffered in the driver with interrupts disabled.
*
* Currently, this function on (a) dumps the interrupt buffer (if the
* SYSLOG interrupt buffer is enabled), and (b) only the SYSLOG interface
* supports supports the 'sc_force()' method.
*
* Input Parameters:
* ch - The character to add to the SYSLOG (must be positive).
*
* Returned Value:
* Zero (OK)is returned on success. A negated errno value is returned
* on any failure.
*
****************************************************************************/
int syslog_flush(void)
{
DEBUGASSERT(g_syslog_channel != NULL);
#ifdef CONFIG_SYSLOG_INTBUFFER
/* Flush any characters that may have been added to the interrupt
* buffer.
*/
syslog_flush_intbuffer(g_syslog_channel, true);
#endif
/* Then flush all of the buffered output to the SYSLOG device */
if (g_syslog_channel->sc_flush != NULL)
{
return g_syslog_channel->sc_flush();
}
return OK;
}