px4-firmware/nuttx/sched/prctl.c

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/************************************************************************
* sched/prctl.c
*
* Copyright (C) 2012 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 <sys/prctl.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/sched.h>
#include "os_internal.h"
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/****************************************************************************
* Name: prctl
*
* Description:
* prctl() is called with a first argument describing what to do (with
* values PR_* defined above) and with additional arguments depending on
* the specific command.
*
* Returned Value:
* The returned value may depend on the specific commnand. For PR_SET_NAME
* and PR_GET_NAME, the returned value of 0 indicates successful operation.
* On any failure, -1 is retruend and the errno value is set appropriately.
*
* EINVAL The value of 'option' is not recognized.
* EFAULT optional arg1 is not a valid address.
* ESRCH No task/thread can be found corresponding to that specified
* by optional arg1.
*
****************************************************************************/
int prctl(int option, ...)
{
va_list ap;
int err;
va_start(ap, option);
switch (option)
{
case PR_SET_NAME:
case PR_GET_NAME:
#if CONFIG_TASK_NAME_SIZE > 0
{
/* Get the prctl arguments */
char *name = va_arg(ap, char *);
int pid = va_arg(ap, int);
FAR _TCB *tcb;
/* Get the TCB associated with the PID (handling the special case of
* pid==0 meaning "this thread")
*/
if (!pid)
{
tcb = (FAR _TCB *)g_readytorun.head;
}
else
{
tcb = sched_gettcb(pid);
}
/* An invalid pid will be indicated by a NULL TCB returned from
* sched_gettcb()
*/
if (!tcb)
{
sdbg("Pid does not correspond to a task: %d\n", pid);
err = ESRCH;
goto errout;
}
/* A pointer to the task name storage must also be provided */
if (!name)
{
sdbg("No name provide\n");
err = EFAULT;
goto errout;
}
/* Now get or set the task name */
if (option == PR_SET_NAME)
{
/* tcb->name may not be null-terminated */
strncpy(tcb->name, name, CONFIG_TASK_NAME_SIZE);
}
else
{
/* The returned value will be null-terminated, truncating if necessary */
strncpy(name, tcb->name, CONFIG_TASK_NAME_SIZE-1);
name[CONFIG_TASK_NAME_SIZE-1] = '\0';
}
}
break;
#else
sdbg("Option not enabled: %d\n", option);
err = ENOSYS;
goto errout;
#endif
default:
sdbg("Unrecognized option: %d\n", option);
err = EINVAL;
goto errout;
}
va_end(ap);
return OK;
errout:
va_end(ap);
set_errno(err);
return ERROR;
}