On Sat, Apr 06, 2002 at 09:49:57PM -0500, Rob Radez wrote:
> I've put up a patch on http://osinvestor.com/bigwatchdog.diff against
> 2.4.19-pre5-ac3. The diff is 33k, and it affects 19 files in drivers/char/,
And the purpose of this patch is...
1. copy_to_user is like memcpy() - it takes two pointers and an integer
size. You're passing it two integers and a pointer:
static int wdt977_ioctl(... unsigned long arg)
...
case WDIOC_GETSTATUS:
if(copy_to_user(arg, &timer_alive, sizeof(timer_alive)))
return -EFAULT;
return 0;
2. sizeof(int) != sizeof(unsigned long). You've changed the ABI in an
unsafe manner on 64-bit machines. The ABI is defined by the ioctl
numbers, which specify an 'int' type.
3. copy_to_user of an int or unsigned long is a bit inefficient. Why
not use put_user to write an int or unsigned long?
4. Unless I'm missing something, WDIOC_GETSTATUS can only ever return
an indication that the timer is open/alive - it's set when the driver
is opened, and cleared when it is closed. Since you can't perform
an ioctl on a closed device, the times that you can perform the ioctl,
it'll always give you a non-zero result.
5. WDIOC_GETSTATUS is supposed to return the WDIOF_* flags. Returning
"watchdog active" as bit 0 causes it to indicate WDIOF_OVERHEAT.
--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux
http://www.arm.linux.org.uk/personal/aboutme.html
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This archive was generated by hypermail 2b29 : Sun Apr 07 2002 - 22:00:20 EST