nuttx/libs/libc/modlib/modlib_symtab.c

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/****************************************************************************
* libs/libc/modlib/modlib_symtab.c
*
* Copyright (C) 2015, 2017-2018 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 <assert.h>
#include <nuttx/symtab.h>
#include <nuttx/lib/modlib.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_MODLIB_HAVE_SYMTAB
/* Symbol table used by dlsym */
# ifndef CONFIG_MODLIB_SYMTAB_ARRAY
# error "CONFIG_MODLIB_SYMTAB_ARRAY must be defined"
# endif
/* Number of Symbols in the Table */
# ifndef CONFIG_MODLIB_NSYMBOLS_VAR
# error "CONFIG_MODLIB_NSYMBOLS_VAR must be defined"
# endif
#endif
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef CONFIG_MODLIB_HAVE_SYMTAB
extern const struct symtab_s CONFIG_MODLIB_SYMTAB_ARRAY[];
extern int CONFIG_MODLIB_NSYMBOLS_VAR;
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static FAR const struct symtab_s *g_modlib_symtab;
static FAR int g_modlib_nsymbols;
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: modlib_getsymtab
*
* Description:
* Get the current kernel symbol table selection as an atomic operation.
*
* Input Parameters:
* symtab - The location to store the symbol table.
* nsymbols - The location to store the number of symbols in the symbol
* table.
*
* Returned Value:
* None
*
****************************************************************************/
void modlib_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols)
{
DEBUGASSERT(symtab != NULL && nsymbols != NULL);
/* Borrow the registry lock to assure atomic access */
modlib_registry_lock();
#ifdef CONFIG_MODLIB_HAVE_SYMTAB
if (g_modlib_symtab == NULL)
{
g_modlib_symtab = CONFIG_MODLIB_SYMTAB_ARRAY;
g_modlib_nsymbols = CONFIG_MODLIB_NSYMBOLS_VAR;
}
#endif
*symtab = g_modlib_symtab;
*nsymbols = g_modlib_nsymbols;
modlib_registry_unlock();
}
/****************************************************************************
* Name: modlib_setsymtab
*
* Description:
* Select a new kernel symbol table selection as an atomic operation.
*
* Input Parameters:
* symtab - The new symbol table.
* nsymbols - The number of symbols in the symbol table.
*
* Returned Value:
* None
*
****************************************************************************/
void modlib_setsymtab(FAR const struct symtab_s *symtab, int nsymbols)
{
/* Borrow the registry lock to assure atomic access */
modlib_registry_lock();
g_modlib_symtab = symtab;
g_modlib_nsymbols = nsymbols;
modlib_registry_unlock();
}