Re: [patch 3/4] split usermodehelper setup from execution

[Randy Dunlap <randy.dunlap@oracle.com>]

On Tue, 08 May 2007 13:51:32 -0700 Jeremy Fitzhardinge wrote:

> --- a/kernel/kmod.c
> +++ b/kernel/kmod.c
> @@ -253,11 +262,94 @@ static void __call_usermodehelper(struct
>  }
>  
>  /**
> - * call_usermodehelper_keys - start a usermode application
> - * @path: pathname for the application
> - * @argv: null-terminated argument list
> - * @envp: null-terminated environment list
> - * @session_keyring: session keyring for process (NULL for an empty keyring)
> + * call_usermodehelper_setup - prepare to call a usermode helper
> + * @path - path to usermode executable
> + * @argv - arg vector for process
> + * @envp - environment for process

s / - /: / above please.

> + *
> + * 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.
> + */
> +struct subprocess_info *call_usermodehelper_setup(char *path,
> +						  char **argv, char **envp)
> +{
> +}
> +EXPORT_SYMBOL(call_usermodehelper_setup);
> +
> +/**
> + * call_usermodehelper_setkeys - set the session keys for usermode helper
> + * @info - a subprocess_info returned by call_usermodehelper_setup
> + * @session_keyring - the session keyring for the process

and here.

> + */
> +
> +/**
> + * call_usermodehelper_setcleanup - set a cleanup function
> + * @info  - a subprocess_info returned by call_usermodehelper_setup
> + * @cleanup - a cleanup function

again.

> + *
> + * The cleanup function is just befor 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.
> + */
> +void call_usermodehelper_setcleanup(struct subprocess_info *info,
> +				    void (*cleanup)(char **argv, char **envp))
> +{
> +	info->cleanup = cleanup;
> +}
> +EXPORT_SYMBOL(call_usermodehelper_setcleanup);
> +
> +/**
> + * call_usermodehelper_stdinpipe - set up a pipe to be used for stdin
> + * @sub_info - a subprocess_info returned by call_usermodehelper_setup
> + * @filp - set to the write-end of a pipe

again.

> + *
> + * This constructs a pipe, and sets the read end to be the stdin of the
> + * subprocess, and returns the write-end in *@filp.
> + */
> +int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
> +				  struct file **filp)
> +{
> +}
> +EXPORT_SYMBOL(call_usermodehelper_stdinpipe);

...

> +/**
> + * call_usermodehelper_pipe - call a usermode helper process with a pipe stdin
> + * @path - path to usermode executable
> + * @argv - arg vector for process
> + * @envp - environment for process
> + * @filp - set to the write-end of a pipe

and here.

> + *
> + * This is a simple wrapper which executes a usermode-helper function
> + * with a pipe as stdin.  It is implemented entirely in terms of
> + * lower-level call_usermodehelper_* functions.
> + */
>  int call_usermodehelper_pipe(char *path, char **argv, char **envp,
>  			     struct file **filp)
>  {


---
~Randy
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