Re: -Wswitch Clang warnings in drivers/scsi

[Bart Van Assche <bvanassche@acm.org>]

On Thu, 2018-10-04 at 23:57 -0700, Nathan Chancellor wrote:
> Regardless of how the overflow is handled within the switch statement,
> the overflow is also happening when passing in these values to the ioctl,
> right? I mean these case values are defined in the uapi files so that
> userspace can easily pass them in to the ioctl, meaning those values are
> being passed in as a signed integer and I would assume subsequently
> overflowing unless I'm just missing something here.

From the user space header <sys/ioctl.h>:

extern int ioctl (int __fd, unsigned long int __request, ...) __THROW;

From the kernel header <linux/fs.h>:

	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);

Why has the second argument been declared as "unsigned long" in the glibc
headers and as "unsigned int" in the kernel headers? That's not clear to me.

Bart.