kernel/kmod.c: document call_usermodehelper_fns() a bit
This function's interface is, uh, subtle. Attempt to apologise for it.
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/kmod.c b/kernel/kmod.c
index ff2c7cb..2a83515 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -577,6 +577,12 @@
return retval;
}
+/*
+ * call_usermodehelper_fns() will not run the caller-provided cleanup function
+ * if a memory allocation failure is experienced. So the caller might need to
+ * check the call_usermodehelper_fns() return value: if it is -ENOMEM, perform
+ * the necessaary cleanup within the caller.
+ */
int call_usermodehelper_fns(
char *path, char **argv, char **envp, int wait,
int (*init)(struct subprocess_info *info, struct cred *new),