/**************************************************************************** * binfmt/binfmt_exec.c * * Copyright (C) 2009, 2013-2014, 2017-2018, 2020 Gregory Nutt. All rights * reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include "binfmt.h" #ifndef CONFIG_BINFMT_DISABLE /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: exec_spawn * * Description: * exec() configurable version, delivery the spawn attribute if this * process has special customization. * * Input Parameters: * filename - The path to the program to be executed. If * CONFIG_LIB_ENVPATH 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. * exports - The address of the start of the caller-provided symbol * table. This symbol table contains the addresses of symbols * exported by the caller and made available for linking the * module into the system. * nexports - The number of symbols in the exports table. * attr - The spawn attributes. * * Returned Value: * It returns the PID of the exec'ed module. On failure, it returns * the negative errno value appropriately. * ****************************************************************************/ int exec_spawn(FAR const char *filename, FAR char * const *argv, FAR const struct symtab_s *exports, int nexports, FAR const posix_spawnattr_t *attr) { FAR struct binary_s *bin; int pid; int ret; /* Allocate the load information */ bin = (FAR struct binary_s *)kmm_zalloc(sizeof(struct binary_s)); if (!bin) { berr("ERROR: Failed to allocate binary_s\n"); ret = -ENOMEM; goto errout; } /* Initialize the binary structure */ bin->filename = filename; bin->exports = exports; bin->nexports = nexports; /* Copy the argv[] list */ ret = binfmt_copyargv(bin, argv); if (ret < 0) { berr("ERROR: Failed to copy argv[]: %d\n", ret); goto errout_with_bin; } /* Load the module into memory */ ret = load_module(bin); if (ret < 0) { berr("ERROR: Failed to load program '%s': %d\n", filename, ret); goto errout_with_argv; } /* Update the spawn attribute */ if (attr) { if (attr->priority > 0) { bin->priority = attr->priority; } #ifndef CONFIG_BUILD_KERNEL if (attr->stacksize > 0) { bin->stacksize = attr->stacksize; } #endif } /* Disable pre-emption so that the executed module does * not return until we get a chance to connect the on_exit * handler. */ sched_lock(); /* Then start the module */ pid = exec_module(bin); if (pid < 0) { ret = pid; berr("ERROR: Failed to execute program '%s': %d\n", filename, ret); goto errout_with_lock; } #ifdef CONFIG_BINFMT_LOADABLE /* Set up to unload the module (and free the binary_s structure) * when the task exists. */ ret = group_exitinfo(pid, bin); if (ret < 0) { berr("ERROR: Failed to schedule unload '%s': %d\n", filename, ret); } #else /* Free the binary_s structure here */ binfmt_freeargv(bin); kmm_free(bin); /* TODO: How does the module get unloaded in this case? */ #endif sched_unlock(); return pid; errout_with_lock: sched_unlock(); unload_module(bin); errout_with_argv: binfmt_freeargv(bin); errout_with_bin: kmm_free(bin); errout: return ret; } /**************************************************************************** * Name: exec * * Description: * This is a convenience function that wraps load_ and exec_module into * one call. If CONFIG_BINFMT_LOADABLE is defined, this function will * schedule to unload the module when task exits. * * This non-standard, NuttX function is similar to execv() and * posix_spawn() but differs in the following ways; * * - Unlike execv() and posix_spawn() this function accepts symbol table * information as input parameters. This means that the symbol table * used to link the application prior to execution is provided by the * caller, not by the system. * - Unlike execv(), this function always returns. * * This non-standard interface is included as a official NuttX API only * because it is needed in certain build modes: exec() is probably the * only way to load programs in the PROTECTED mode. Other file execution * APIs rely on a symbol table provided by the OS. In the PROTECTED build * mode, the OS cannot provide any meaningful symbolic information for * execution of code in the user-space blob so that is the exec() function * is really needed in that build case * * The interface is available in the FLAT build mode although it is not * really necessary in that case. It is currently used by some example * code under the apps/ that that generate their own symbol tables for * linking test programs. So although it is not necessary, it can still * be useful. * * The interface would be completely useless and will not be supported in * in the KERNEL build mode where the contrary is true: An application * process cannot provide any meaningful symbolic information for use in * linking a different process. * * NOTE: This function is flawed and useless without CONFIG_BINFMT_LOADABLE * because without that features there is then no mechanism to unload the * module once it exits. * * Input Parameters: * filename - The path to the program to be executed. If * CONFIG_LIB_ENVPATH 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. * exports - The address of the start of the caller-provided symbol * table. This symbol table contains the addresses of symbols * exported by the caller and made available for linking the * module into the system. * nexports - The number of symbols in the exports table. * * Returned Value: * This is an end-user function, so it follows the normal convention: * It returns the PID of the exec'ed module. On failure, it returns * -1 (ERROR) and sets errno appropriately. * ****************************************************************************/ int exec(FAR const char *filename, FAR char * const *argv, FAR const struct symtab_s *exports, int nexports) { int ret; ret = exec_spawn(filename, argv, exports, nexports, NULL); if (ret < 0) { set_errno(-ret); ret = ERROR; } return ret; } #endif /* !CONFIG_BINFMT_DISABLE */