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: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200918100926.1447563-1-arnd@arndb.de
This commit is contained in:
Arnd Bergmann 2020-09-18 12:09:04 +02:00 committed by Sam Ravnborg
parent 8bde6c0d4e
commit 06f4277463

View file

@ -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;
struct fb_cmap32 cmap32;
struct fb_cmap cmap_from;
struct fb_cmap_user cmap;
cmap = compat_alloc_user_space(sizeof(*cmap));
cmap32 = compat_ptr(arg);
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,