Disallow disabling of the watchdog timer unless a particular
character ('V') was recently written to the watchdog device.
Signed-off-by: Dale Farnsworth <[EMAIL PROTECTED]>
---
drivers/char/watchdog/mv64x60_wdt.c | 28 ++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)
Index: linux-2.6-powerpc-wdt/drivers/char/watchdog/mv64x60_wdt.c
===================================================================
--- linux-2.6-powerpc-wdt.orig/drivers/char/watchdog/mv64x60_wdt.c
2007-07-20 19:32:41.000000000 +0000
+++ linux-2.6-powerpc-wdt/drivers/char/watchdog/mv64x60_wdt.c 2007-07-20
19:33:30.000000000 +0000
@@ -44,6 +44,7 @@ static int wdt_status;
static void __iomem *mv64x60_wdt_regs;
static int mv64x60_wdt_timeout;
static unsigned int bus_clk;
+static char expect_close;
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
@@ -115,10 +116,14 @@ static int mv64x60_wdt_open(struct inode
static int mv64x60_wdt_release(struct inode *inode, struct file *file)
{
- mv64x60_wdt_service();
-
- if (!nowayout)
+ if (expect_close == 42)
mv64x60_wdt_handler_disable();
+ else {
+ printk(KERN_CRIT
+ "mv64x60_wdt: unexpected close, not stopping timer!\n");
+ mv64x60_wdt_service();
+ }
+ expect_close = 0;
clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
@@ -128,8 +133,22 @@ static int mv64x60_wdt_release(struct in
static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t * ppos)
{
- if (len)
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ expect_close = 0;
+
+ for (i = 0; i != len; i++) {
+ char c;
+ if(get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
mv64x60_wdt_service();
+ }
return len;
}
@@ -142,6 +161,7 @@ static int mv64x60_wdt_ioctl(struct inod
void __user *argp = (void __user *)arg;
static struct watchdog_info info = {
.options = WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.firmware_version = 0,
.identity = "MV64x60 watchdog",
-
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