nuttx/sched/module/mod_modsym.c
Xiang Xiao ebcb03dce9 libc/symtab: Don't include symtab.h in the header files
to unify the inclusion of symtab.h only from the source files

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2023-07-10 23:03:17 +03:00

117 lines
3.9 KiB
C

/****************************************************************************
* sched/module/mod_modsym.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/symtab.h>
#include <nuttx/module.h>
#include <nuttx/lib/modlib.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: modsym
*
* Description:
* modsym() returns the address of a symbol defined within the object that
* was previously made accessible through a insmod() call. handle is the
* value returned from a call to insmod() (and which has not since been
* released via a call to rmmod()), name is the symbol's name as a
* character string.
*
* The returned symbol address will remain valid until rmmod() is called.
*
* Input Parameters:
* handle - The opaque, non-NULL value returned by a previous successful
* call to insmod().
* name - A pointer to the symbol name string.
*
* Returned Value:
* The address associated with the symbol is returned on success.
* If handle does not refer to a valid module opened by insmod(), or if
* the named symbol cannot be found within any of the objects associated
* with handle, modsym() will return NULL and the errno variable will be
* set appropriately.
*
* NOTE: This means that the address zero can never be a valid return
* value.
*
****************************************************************************/
FAR const void *modsym(FAR void *handle, FAR const char *name)
{
FAR struct module_s *modp = (FAR struct module_s *)handle;
FAR const struct symtab_s *symbol;
int err;
int ret;
/* Verify that the module is in the registry */
modlib_registry_lock();
ret = modlib_registry_verify(modp);
if (ret < 0)
{
berr("ERROR: Failed to verify module: %d\n", ret);
err = -ret;
goto errout_with_lock;
}
/* Does the module have a symbol table? */
if (modp->modinfo.exports == NULL || modp->modinfo.nexports == 0)
{
berr("ERROR: Module has no symbol table\n");
err = ENOENT;
goto errout_with_lock;
}
/* Search the symbol table for the matching symbol */
symbol = symtab_findbyname(modp->modinfo.exports, name,
modp->modinfo.nexports);
if (symbol == NULL)
{
berr("ERROR: Failed to find symbol in symbol \"%s\" in table\n", name);
err = ENOENT;
goto errout_with_lock;
}
/* Return the address within the module associated with the symbol */
modlib_registry_unlock();
DEBUGASSERT(symbol->sym_value != NULL);
return symbol->sym_value;
errout_with_lock:
modlib_registry_unlock();
set_errno(err);
return NULL;
}