cifs: add pid of initiating process to spnego upcall info

cifs: add pid of initiating process to spnego upcall info

This will allow the upcall to poke in /proc/<pid>/environ and get
the value of the $KRB5CCNAME env var for the process.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifs_spnego.c

@@ -86,6 +86,9 @@ struct key_type cifs_spnego_key_type = {
 /* strlen of ";user=" */
 #define USER_KEY_LEN		6
 
+/* strlen of ";pid=0x" */
+#define PID_KEY_LEN		7
+
 /* get a key struct with a SPNEGO security blob, suitable for session setup */
 struct key *
 cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
@@ -103,7 +106,8 @@ cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
 		   IP_KEY_LEN + INET6_ADDRSTRLEN +
 		   MAX_MECH_STR_LEN +
 		   UID_KEY_LEN + (sizeof(uid_t) * 2) +
-		   USER_KEY_LEN + strlen(sesInfo->userName) + 1;
+		   USER_KEY_LEN + strlen(sesInfo->userName) +
+		   PID_KEY_LEN + (sizeof(pid_t) * 2) + 1;
 
 	spnego_key = ERR_PTR(-ENOMEM);
 	description = kzalloc(desc_len, GFP_KERNEL);
@@ -141,6 +145,9 @@ cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
 	dp = description + strlen(description);
 	sprintf(dp, ";user=%s", sesInfo->userName);
 
+	dp = description + strlen(description);
+	sprintf(dp, ";pid=0x%x", current->pid);
+
 	cFYI(1, ("key description = %s", description));
 	spnego_key = request_key(&cifs_spnego_key_type, description, "");