usermodehelper: split setup from execution
Rather than having hundreds of variations of call_usermodehelper for
various pieces of usermode state which could be set up, split the
info allocation and initialization from the actual process execution.
This means the general pattern becomes:
info = call_usermodehelper_setup(path, argv, envp); /* basic state */
call_usermodehelper_<SET EXTRA STATE>(info, stuff...); /* extra state */
call_usermodehelper_exec(info, wait); /* run process and free info */
This patch introduces wrappers for all the existing calling styles for
call_usermodehelper_*, but folds their implementations into one.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Bj?rn Steinbrink <B.Steinbrink@gmx.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 10f505c..c4cbe59 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -36,13 +36,51 @@
#define try_then_request_module(x, mod...) ((x) ?: (request_module(mod), (x)))
struct key;
-extern int call_usermodehelper_keys(char *path, char *argv[], char *envp[],
- struct key *session_keyring, int wait);
+struct file;
+struct subprocess_info;
+
+/* Allocate a subprocess_info structure */
+struct subprocess_info *call_usermodehelper_setup(char *path,
+ char **argv, char **envp);
+
+/* Set various pieces of state into the subprocess_info structure */
+void call_usermodehelper_setkeys(struct subprocess_info *info,
+ struct key *session_keyring);
+int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
+ struct file **filp);
+void call_usermodehelper_setcleanup(struct subprocess_info *info,
+ void (*cleanup)(char **argv, char **envp));
+
+/* Actually execute the sub-process */
+int call_usermodehelper_exec(struct subprocess_info *info, int wait);
+
+/* Free the subprocess_info. This is only needed if you're not going
+ to call call_usermodehelper_exec */
+void call_usermodehelper_freeinfo(struct subprocess_info *info);
static inline int
call_usermodehelper(char *path, char **argv, char **envp, int wait)
{
- return call_usermodehelper_keys(path, argv, envp, NULL, wait);
+ struct subprocess_info *info;
+
+ info = call_usermodehelper_setup(path, argv, envp);
+ if (info == NULL)
+ return -ENOMEM;
+ return call_usermodehelper_exec(info, wait);
+}
+
+static inline int
+call_usermodehelper_keys(char *path, char **argv, char **envp,
+ struct key *session_keyring, int wait)
+{
+ struct subprocess_info *info;
+
+ info = call_usermodehelper_setup(path, argv, envp);
+ if (info == NULL)
+ return -ENOMEM;
+
+ call_usermodehelper_setkeys(info, session_keyring);
+ return call_usermodehelper_exec(info, wait);
}
extern void usermodehelper_init(void);