nuttx/arch/xtensa/src/common/xtensa_checkstack.c

/****************************************************************************
 * arch/xtensa/src/common/xtensa_checkstack.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 <sys/types.h>
#include <stdint.h>
#include <sched.h>
#include <assert.h>
#include <debug.h>

#include <nuttx/arch.h>
#include <nuttx/tls.h>
#include <nuttx/board.h>

#include "xtensa.h"
#include "sched/sched.h"

#ifdef CONFIG_STACK_COLORATION

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static size_t do_stackcheck(uintptr_t alloc, size_t size);

/****************************************************************************
 * Name: do_stackcheck
 *
 * Description:
 *   Determine (approximately) how much stack has been used be searching the
 *   stack memory for a high water mark.  That is, the deepest level of the
 *   stack that clobbered some recognizable marker in the stack memory.
 *
 * Input Parameters:
 *   alloc - Allocation base address of the stack
 *   size - The size of the stack in bytes
 *
 * Returned Value:
 *   The estimated amount of stack space used.
 *
 ****************************************************************************/

static size_t do_stackcheck(uintptr_t alloc, size_t size)
{
  FAR uintptr_t start;
  FAR uintptr_t end;
  FAR uint32_t *ptr;
  size_t mark;

  if (size == 0)
    {
      return 0;
    }

  /* Get aligned addresses of the top and bottom of the stack */

#ifdef CONFIG_TLS
  /* Skip over the TLS data structure at the bottom of the stack */

  DEBUGASSERT((alloc & TLS_STACK_MASK) == 0);
  start = alloc + sizeof(struct tls_info_s);
#else
  start = alloc & ~3;
#endif
  end   = (alloc + size + 3) & ~3;

  /* Get the adjusted size based on the top and bottom of the stack */

  size  = end - start;

  /* The Xtensa CPUs use a push-down stack:  the stack grows toward lower
   * addresses in memory.  We need to start at the lowest address in the
   * stack memory allocation and search to higher addresses.  The first word
   * we encounter that does not have the magic value is the high water mark.
   */

  for (ptr = (FAR uint32_t *)start, mark = (size >> 2);
       *ptr == STACK_COLOR && mark > 0;
       ptr++, mark--);

  /* If the stack is completely used, then this might mean that the stack
   * overflowed from above (meaning that the stack is too small), or may
   * have been overwritten from below meaning that some other stack or data
   * structure overflowed.
   *
   * If you see returned values saying that the entire stack is being used
   * then enable the following logic to see it there are unused areas in the
   * middle of the stack.
   */

#if 0
  if (mark + 16 > nwords)
    {
      int i;
      int j;

      ptr = (FAR uint32_t *)start;
      for (i = 0; i < size; i += 4*64)
        {
          for (j = 0; j < 64; j++)
            {
              int ch;
              if (*ptr++ == STACK_COLOR)
                {
                  ch = '.';
                }
              else
                {
                  ch = 'X';
                }

              up_putc(ch);
            }

          up_putc('\n');
        }
    }
#endif

  /* Return our guess about how much stack space was used */

  return mark << 2;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_check_stack and friends
 *
 * Description:
 *   Determine (approximately) how much stack has been used be searching the
 *   stack memory for a high water mark.  That is, the deepest level of the
 *   stack that clobbered some recognizable marker in the stack memory.
 *
 * Input Parameters:
 *   None
 *
 * Returned Value:
 *   The estimated amount of stack space used.
 *
 ****************************************************************************/

size_t up_check_tcbstack(FAR struct tcb_s *tcb)
{
  return do_stackcheck((uintptr_t)tcb->stack_alloc_ptr, tcb->adj_stack_size);
}

ssize_t up_check_tcbstack_remain(FAR struct tcb_s *tcb)
{
  return (ssize_t)tcb->adj_stack_size - (ssize_t)up_check_tcbstack(tcb);
}

size_t up_check_stack(void)
{
  return up_check_tcbstack(this_task());
}

ssize_t up_check_stack_remain(void)
{
  return up_check_tcbstack_remain(this_task());
}

#if CONFIG_ARCH_INTERRUPTSTACK > 3
size_t up_check_intstack(void)
{
  return do_stackcheck((uintptr_t)&g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~3));
}

size_t up_check_intstack_remain(void)
{
  return (CONFIG_ARCH_INTERRUPTSTACK & ~3) - up_check_intstack();
}
#endif

#endif /* CONFIG_STACK_COLORATION */