Re: [PATCH] incorrect use of sizeof() in ioctl definitions

[Andrew Morton]

Arun Sharma <arun.sharma@xxxxxxxxx> wrote:
>
> Some drivers seem to use macros such as _IOR/_IOW in a way that ends up calling the sizeof() operator twice. For eg:
> 
> -#define FBIO_ATY128_GET_MIRROR	_IOR('@', 1, sizeof(__u32*))
> +#define FBIO_ATY128_GET_MIRROR	_IOR('@', 1, __u32*)
> 
> from include/asm-ia64/ioctl.h (other archs are similar):
> 
> #define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),sizeof(size))

Matthew Wilcox fixed all except one of these a while back.  What is left
over is this chunk:


diff -puN drivers/video/aty/aty128fb.c~sizeof-in-ioctl-fix drivers/video/aty/aty128fb.c
--- 25/drivers/video/aty/aty128fb.c~sizeof-in-ioctl-fix	Tue Sep 30 14:04:12 2003
+++ 25-akpm/drivers/video/aty/aty128fb.c	Tue Sep 30 14:04:12 2003
@@ -2041,9 +2041,9 @@ aty128fb_setcolreg(u_int regno, u_int re
 #define ATY_MIRROR_CRT_ON	0x00000002
 
 /* out param: u32*	backlight value: 0 to 15 */
-#define FBIO_ATY128_GET_MIRROR	_IOR('@', 1, sizeof(__u32*))
+#define FBIO_ATY128_GET_MIRROR	_IOR('@', 1, __u32*)
 /* in param: u32*	backlight value: 0 to 15 */
-#define FBIO_ATY128_SET_MIRROR	_IOW('@', 2, sizeof(__u32*))
+#define FBIO_ATY128_SET_MIRROR	_IOW('@', 2, __u32*)
 
 static int aty128fb_ioctl(struct inode *inode, struct file *file, u_int cmd,
 			  u_long arg, struct fb_info *info)


Matthew's conversion mainly converted things to size_t, but from the looks
of it, __u32* is the right thing to use in this case, I think?

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