f6485fe177
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5504 42af7a65-404d-4744-a932-0658087f49c3
168 lines
6.6 KiB
C
168 lines
6.6 KiB
C
/****************************************************************************
|
|
* libc/unistd/lib_execv.c
|
|
*
|
|
* Copyright (C) 2013 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 <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/binfmt/binfmt.h>
|
|
|
|
#ifdef CONFIG_LIBC_EXECFUNCS
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
/* If CONFIG_LIBC_EXECFUNCS is defined in the configuration, then the
|
|
* following must also be defined:
|
|
*/
|
|
|
|
/* Symbol table used by exec[l|v] */
|
|
|
|
#ifndef CONFIG_EXECFUNCS_SYMTAB
|
|
# error "CONFIG_EXECFUNCS_SYMTAB must be defined"
|
|
#endif
|
|
|
|
/* Number of Symbols in the Table */
|
|
|
|
#ifndef CONFIG_EXECFUNCS_NSYMBOLS
|
|
# error "CONFIG_EXECFUNCS_NSYMBOLS must be defined"
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Variables
|
|
****************************************************************************/
|
|
|
|
extern struct symtab_s CONFIG_EXECFUNCS_SYMTAB;
|
|
|
|
/****************************************************************************
|
|
* Private Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: execv
|
|
*
|
|
* Description:
|
|
* The standard 'exec' family of functions will replace the current process
|
|
* image with a new process image. The new image will be constructed from a
|
|
* regular, executable file called the new process image file. There will
|
|
* be no return from a successful exec, because the calling process image
|
|
* is overlaid by the new process image.
|
|
*
|
|
* Simplified 'execl()' and 'execv()' functions are provided by NuttX for
|
|
* compatibility. NuttX is a tiny embedded RTOS that does not support
|
|
* processes and hence the concept of overlaying a tasks process image with
|
|
* a new process image does not make any sense. In NuttX, these functions
|
|
* are wrapper functions that:
|
|
*
|
|
* 1. Call the non-standard binfmt function 'exec', and then
|
|
* 2. exit(0).
|
|
*
|
|
* Note the inefficiency when 'exec[l|v]()' is called in the normal, two-
|
|
* step process: (1) first call vfork() to create a new thread, then (2)
|
|
* call 'exec[l|v]()' to replace the new thread with a program from the
|
|
* file system. Since the new thread will be terminated by the
|
|
* 'exec[l|v]()' call, it really served no purpose other than to support
|
|
* Unix compatility.
|
|
*
|
|
* The non-standard binfmt function 'exec()' needs to have (1) a symbol
|
|
* table that provides the list of symbols exported by the base code, and
|
|
* (2) the number of symbols in that table. This information is currently
|
|
* provided to 'exec()' from 'exec[l|v]()' via NuttX configuration settings:
|
|
*
|
|
* CONFIG_LIBC_EXECFUNCS : Enable exec[l|v] support
|
|
* CONFIG_EXECFUNCS_SYMTAB : Symbol table used by exec[l|v]
|
|
* CONFIG_EXECFUNCS_NSYMBOLS : Number of symbols in the table
|
|
*
|
|
* As a result of the above, the current implementations of 'execl()' and
|
|
* 'execv()' suffer from some incompatibilities that may or may not be
|
|
* addressed in a future version of NuttX. Other than just being an
|
|
* inefficient use of MCU resource, the most serious of these is that
|
|
* the exec'ed task will not have the same task ID as the vfork'ed
|
|
* function. So the parent function cannot know the ID of the exec'ed
|
|
* task.
|
|
*
|
|
* Input Parameters:
|
|
* path - The path to the program to be executed. If CONFIG_BINFMT_EXEPATH
|
|
* is defined in the configuration, then this may be a relative path
|
|
* from the current working directory. Otherwise, path must be the
|
|
* absolute path to the program.
|
|
* argv - A pointer to an array of string arguments. The end of the
|
|
* array is indicated with a NULL entry.
|
|
*
|
|
* Returned Value:
|
|
* This function does not return on success. On failure, it will return
|
|
* -1 (ERROR) and will set the 'errno' value appropriately.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int execv(FAR const char *path, FAR char *const argv[])
|
|
{
|
|
int ret;
|
|
|
|
/* Start the task */
|
|
|
|
ret = exec(path, (FAR const char **)argv,
|
|
&CONFIG_EXECFUNCS_SYMTAB, CONFIG_EXECFUNCS_NSYMBOLS);
|
|
|
|
if (ret < 0)
|
|
{
|
|
sdbg("exec failed: %d\n", errno);
|
|
return ERROR;
|
|
}
|
|
|
|
/* Then exit */
|
|
|
|
exit(0);
|
|
|
|
/* We should not get here, but might be needed by some compilers. Other,
|
|
* smarter compilers might complain that this code is unreachable. You just
|
|
* can't win.
|
|
*/
|
|
|
|
return ERROR;
|
|
}
|
|
|
|
#endif /* CONFIG_LIBC_EXECFUNCS */ |