param: remove unnecessary writable charp

sysfs-writable charp arguments need to be locked against modification
(since the old ones may be kfreed underneath us).  String arguments
are much simpler, so use them for small strings (eg. IFNAMSIZ).

lkdtm only uses the parameters at module initialization time, so there's
not much point making them writable.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: M. Mohan Kumar <mohan@in.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: devel@driverdev.osuosl.org

drivers/misc/lkdtm.c

@@ -124,9 +124,9 @@ static int count = DEFAULT_COUNT;
 module_param(recur_count, int, 0644);
 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
 				 "default is 10");
-module_param(cpoint_name, charp, 0644);
+module_param(cpoint_name, charp, 0444);
 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
-module_param(cpoint_type, charp, 0644);
+module_param(cpoint_type, charp, 0444);
 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
 				"hitting the crash point");
 module_param(cpoint_count, int, 0644);

drivers/staging/rtl8187se/r8180_core.c

@@ -61,7 +61,7 @@ static struct pci_device_id rtl8180_pci_id_tbl[] __devinitdata = {
 };
 
 
-static char *ifname = "wlan%d";
+static char ifname[IFNAMSIZ] = "wlan%d";
 static int hwseqnum = 0;
 static int hwwep = 0;
 static int channels = 0x3fff;
@@ -72,7 +72,7 @@ MODULE_AUTHOR("Andrea Merello <andreamrl@tiscali.it>");
 MODULE_DESCRIPTION("Linux driver for Realtek RTL8180 / RTL8185 WiFi cards");
 
 
-module_param(ifname, charp, S_IRUGO|S_IWUSR);
+module_param_string(ifname, ifname, sizeof(ifname), S_IRUGO|S_IWUSR);
 module_param(hwseqnum, int, S_IRUGO|S_IWUSR);
 module_param(hwwep, int, S_IRUGO|S_IWUSR);
 module_param(channels, int, S_IRUGO|S_IWUSR);
@@ -3609,7 +3609,7 @@ static int __devinit rtl8180_pci_probe(struct pci_dev *pdev,
 
 	if (dev_alloc_name(dev, ifname) < 0) {
 		DMESG("Oops: devname already taken! Trying wlan%%d...\n");
-		ifname = "wlan%d";
+		strcpy(ifname, "wlan%d");
 		dev_alloc_name(dev, ifname);
 	}
 

drivers/staging/rtl8192e/r8192E_core.c

@@ -112,7 +112,7 @@ static const struct pci_device_id rtl8192_pci_id_tbl[] __devinitdata = {
 	{}
 };
 
-static char* ifname = "wlan%d";
+static char ifname[IFNAMSIZ] = "wlan%d";
 static int hwwep = 1; //default use hw. set 0 to use software security
 static int channels = 0x3fff;
 
@@ -123,7 +123,7 @@ MODULE_DEVICE_TABLE(pci, rtl8192_pci_id_tbl);
 MODULE_DESCRIPTION("Linux driver for Realtek RTL819x WiFi cards");
 
 
-module_param(ifname, charp, S_IRUGO|S_IWUSR );
+module_param_string(ifname, ifname, sizeof(ifname), S_IRUGO|S_IWUSR);
 //module_param(hwseqnum,int, S_IRUGO|S_IWUSR);
 module_param(hwwep,int, S_IRUGO|S_IWUSR);
 module_param(channels,int, S_IRUGO|S_IWUSR);
@@ -6446,7 +6446,7 @@ static int __devinit rtl8192_pci_probe(struct pci_dev *pdev,
 
 	if (dev_alloc_name(dev, ifname) < 0){
                 RT_TRACE(COMP_INIT, "Oops: devname already taken! Trying wlan%%d...\n");
-		ifname = "wlan%d";
+		strcpy(ifname, "wlan%d");
 		dev_alloc_name(dev, ifname);
         }
 

drivers/staging/rtl8192su/r8192U_core.c

@@ -144,13 +144,13 @@ MODULE_VERSION("V 1.1");
 MODULE_DEVICE_TABLE(usb, rtl8192_usb_id_tbl);
 MODULE_DESCRIPTION("Linux driver for Realtek RTL8192 USB WiFi cards");
 
-static char* ifname = "wlan%d";
+static char ifname[IFNAMSIZ] = "wlan%d";
 static int hwwep = 1;  //default use hw. set 0 to use software security
 static int channels = 0x3fff;
 
 
 
-module_param(ifname, charp, S_IRUGO|S_IWUSR );
+module_param_string(ifname, ifname, sizeof(ifname), S_IRUGO|S_IWUSR);
 //module_param(hwseqnum,int, S_IRUGO|S_IWUSR);
 module_param(hwwep,int, S_IRUGO|S_IWUSR);
 module_param(channels,int, S_IRUGO|S_IWUSR);
@@ -7406,7 +7406,7 @@ static int __devinit rtl8192_usb_probe(struct usb_interface *intf,
 
 	if (dev_alloc_name(dev, ifname) < 0){
                 RT_TRACE(COMP_INIT, "Oops: devname already taken! Trying wlan%%d...\n");
-		ifname = "wlan%d";
+		strcpy(ifname, "wlan%d");
 		dev_alloc_name(dev, ifname);
         }