Commit 06f42774 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Sam Ravnborg
Browse files

fbdev: simplify fb_getput_cmap() 



This function is one of the remaining users of compat_alloc_user_space()
and copy_in_user().

Clean it up by copying to a local data structure copy instead,
which also leads to more readable code.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200918100926.1447563-1-arnd@arndb.de
parent 8bde6c0d

drivers/video/fbdev/core/fbmem.c

+19 −25
Original line number Diff line number Diff line
@@ -1215,36 +1215,30 @@ struct fb_cmap32 { 
static int fb_getput_cmap(struct fb_info *info, unsigned int cmd,

			  unsigned long arg)

{

	struct fb_cmap_user __user *cmap;

	struct fb_cmap32 __user *cmap32;

	__u32 data;

	int err;



	cmap = compat_alloc_user_space(sizeof(*cmap));

	cmap32 = compat_ptr(arg);

	struct fb_cmap32 cmap32;

	struct fb_cmap cmap_from;

	struct fb_cmap_user cmap;



	if (copy_in_user(&cmap->start, &cmap32->start, 2 * sizeof(__u32)))

	if (copy_from_user(&cmap32, compat_ptr(arg), sizeof(cmap32)))

		return -EFAULT;



	if (get_user(data, &cmap32->red) ||

	    put_user(compat_ptr(data), &cmap->red) ||

	    get_user(data, &cmap32->green) ||

	    put_user(compat_ptr(data), &cmap->green) ||

	    get_user(data, &cmap32->blue) ||

	    put_user(compat_ptr(data), &cmap->blue) ||

	    get_user(data, &cmap32->transp) ||

	    put_user(compat_ptr(data), &cmap->transp))

		return -EFAULT;

	cmap = (struct fb_cmap_user) {

		.start	= cmap32.start,

		.len	= cmap32.len,

		.red	= compat_ptr(cmap32.red),

		.green	= compat_ptr(cmap32.green),

		.blue	= compat_ptr(cmap32.blue),

		.transp	= compat_ptr(cmap32.transp),

	};



	err = do_fb_ioctl(info, cmd, (unsigned long) cmap);

	if (cmd == FBIOPUTCMAP)

		return fb_set_user_cmap(&cmap, info);



	if (!err) {

		if (copy_in_user(&cmap32->start,

				 &cmap->start,

				 2 * sizeof(__u32)))

			err = -EFAULT;

	}

	return err;

	lock_fb_info(info);

	cmap_from = info->cmap;

	unlock_fb_info(info);



	return fb_cmap_to_user(&cmap_from, &cmap);

}



static int do_fscreeninfo_to_user(struct fb_fix_screeninfo *fix,