usermodehelper: kill the sub_info->path[0] check

call_usermodehelper_exec() does nothing but returns success if path[0] ==
0.  The only user which needs this strange feature is request_module(), it
can check modprobe_path[0] itself like other users do if they want to
detect the "disabled by admin" case.

Kill it.  Not only it looks strange, it can confuse other callers.  And
this allows us to revert 264b83c0 ("usermodehelper: check
subprocess_info->path != NULL"), do_execve(NULL) is safe.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2013-07-03 15:08:15 -07:00 committed by Linus Torvalds
parent 77d5591802
commit 7f57cfa4e2

View file

@ -147,6 +147,9 @@ int __request_module(bool wait, const char *fmt, ...)
*/
WARN_ON_ONCE(wait && current_is_async());
if (!modprobe_path[0])
return 0;
va_start(args, fmt);
ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
va_end(args);
@ -569,14 +572,6 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait)
int retval = 0;
helper_lock();
if (!sub_info->path) {
retval = -EINVAL;
goto out;
}
if (sub_info->path[0] == '\0')
goto out;
if (!khelper_wq || usermodehelper_disabled) {
retval = -EBUSY;
goto out;