3 files changed, 24 insertions, 8 deletions

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index d30cdb4248a9..f5a5bc09b8fa 100644
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -20,6 +20,11 @@
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
 
+static char *sender = "VMRMSVM";
+module_param(sender, charp, 0);
+MODULE_PARM_DESC(sender,
+                 "Guest name that may send SMSG messages (default VMRMSVM)");
+
 #include "../../../drivers/s390/net/smsgiucv.h"
 
 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
@@ -367,10 +372,12 @@ static struct ctl_table cmm_dir_table[] = {
 #ifdef CONFIG_CMM_IUCV
 #define SMSG_PREFIX "CMM"
 static void
-cmm_smsg_target(char *msg)
+cmm_smsg_target(char *from, char *msg)
 {
         long pages, seconds;
 
+        if (strlen(sender) > 0 && strcmp(from, sender) != 0)
+                return;
         if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
                 return;
         if (strncmp(msg, "SHRINK", 6) == 0) {
diff --git a/drivers/s390/net/smsgiucv.c b/drivers/s390/net/smsgiucv.c
index a3d285859564..1e3f7f3c662f 100644
--- a/drivers/s390/net/smsgiucv.c
+++ b/drivers/s390/net/smsgiucv.c
@@ -32,7 +32,7 @@ struct smsg_callback {
         struct list_head list;
         char *prefix;
         int len;
-        void (*callback)(char *str);
+        void (*callback)(char *from, char *str);
 };
 
 MODULE_AUTHOR
@@ -55,8 +55,9 @@ smsg_message_pending(iucv_MessagePending *eib, void *pgm_data)
 {
         struct smsg_callback *cb;
         unsigned char *msg;
+        unsigned char sender[9];
         unsigned short len;
-        int rc;
+        int rc, i;
 
         len = eib->ln1msg2.ipbfln1f;
         msg = kmalloc(len + 1, GFP_ATOMIC|GFP_DMA);
@@ -69,10 +70,18 @@ smsg_message_pending(iucv_MessagePending *eib, void *pgm_data)
         if (rc == 0) {
                 msg[len] = 0;
                 EBCASC(msg, len);
+                memcpy(sender, msg, 8);
+                sender[8] = 0;
+                /* Remove trailing whitespace from the sender name. */
+                for (i = 7; i >= 0; i--) {
+                        if (sender[i] != ' ' && sender[i] != '\t')
+                                break;
+                        sender[i] = 0;
+                }
                 spin_lock(&smsg_list_lock);
                 list_for_each_entry(cb, &smsg_list, list)
                         if (strncmp(msg + 8, cb->prefix, cb->len) == 0) {
-                                cb->callback(msg + 8);
+                                cb->callback(sender, msg + 8);
                                 break;
                         }
                 spin_unlock(&smsg_list_lock);
@@ -91,7 +100,7 @@ static struct device_driver smsg_driver = {
 };
 
 int
-smsg_register_callback(char *prefix, void (*callback)(char *str))
+smsg_register_callback(char *prefix, void (*callback)(char *from, char *str))
 {
         struct smsg_callback *cb;
 
@@ -108,7 +117,7 @@ smsg_register_callback(char *prefix, void (*callback)(char *str))
 }
 
 void
-smsg_unregister_callback(char *prefix, void (*callback)(char *str))
+smsg_unregister_callback(char *prefix, void (*callback)(char *from, char *str))
 {
         struct smsg_callback *cb, *tmp;
 
diff --git a/drivers/s390/net/smsgiucv.h b/drivers/s390/net/smsgiucv.h
index 04cd87152964..67f5d4f8378d 100644
--- a/drivers/s390/net/smsgiucv.h
+++ b/drivers/s390/net/smsgiucv.h
@@ -5,6 +5,6 @@
  * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  */
 
-int  smsg_register_callback(char *, void (*)(char *));
-void smsg_unregister_callback(char *, void (*)(char *));
+int  smsg_register_callback(char *, void (*)(char *, char *));
+void smsg_unregister_callback(char *, void (*)(char *, char *));