Man page 9 : call_usermodehelper_setup

call_usermodehelper_setup - prepare to call a usermode helper

struct subprocess_info * call_usermodehelper_setup(char *  path , char **  argv , char **  envp , gfp_t  gfp_mask , int (* init ) (struct subprocess_info *info, struct cred *new), void (* cleanup ) (struct subprocess_info *info), void *  data );

path
    path to usermode executable

argv
    arg vector for process

envp
    environment for process

gfp_mask
    gfp mask for memory allocation

init
    an init function

cleanup
    a cleanup function

data
    arbitrary context sensitive data

Returns either NULL on allocation failure, or a subprocess_info structure. This should be passed to call_usermodehelper_exec to exec the process and free the structure.

The init function is used to customize the helper process prior to exec. A non-zero return code causes the process to error out, exit, and return the failure to the calling process

The cleanup function is just before ethe subprocess_info is about to be freed. This can be used for freeing the argv and envp. The Function must be runnable in either a process context or the context in which call_usermodehelper_exec is called.