media: v4l2-compat-ioctl32: simplify casts

Making the cast right for get_user/put_user is not trivial, as
it needs to ensure that the types are the correct ones.

Improve it by using macros.

Tested with vivid with:
	$ sudo modprobe vivid no_error_inj=1
	$ v4l2-compliance-32bits -a -s10 >32bits && v4l2-compliance-64bits -a -s10 > 64bits && diff -U0 32bits 64bits
	--- 32bits	2018-04-17 11:18:29.141240772 -0300
	+++ 64bits	2018-04-17 11:18:40.635282341 -0300
	@@ -1 +1 @@
	-v4l2-compliance SHA   : bc71e4a67c6fbc5940062843bc41e7c8679634ce, 32 bits
	+v4l2-compliance SHA   : bc71e4a67c6fbc5940062843bc41e7c8679634ce, 64 bits

Using the latest version of v4l-utils with this patch applied:
	https://patchwork.linuxtv.org/patch/48746/

Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab 2018-04-17 09:01:46 -04:00
parent 6dd0394f5f
commit 09c033b665

View File

@ -30,6 +30,24 @@
get_user(__assign_tmp, from) || put_user(__assign_tmp, to); \
})
#define get_user_cast(__x, __ptr) \
({ \
get_user(__x, (typeof(*__ptr) __user *)(__ptr)); \
})
#define put_user_force(__x, __ptr) \
({ \
put_user((typeof(*__x) __force *)(__x), __ptr); \
})
#define assign_in_user_cast(to, from) \
({ \
typeof(*from) __assign_tmp; \
\
get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\
})
static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
long ret = -ENOIOCTLCMD;
@ -543,8 +561,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
return -EFAULT;
uplane = aux_buf;
if (put_user((__force struct v4l2_plane *)uplane,
&p64->m.planes))
if (put_user_force(uplane, &p64->m.planes))
return -EFAULT;
while (num_planes--) {
@ -683,7 +700,7 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64,
if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
get_user(tmp, &p32->base) ||
put_user((void __force *)compat_ptr(tmp), &p64->base) ||
put_user_force(compat_ptr(tmp), &p64->base) ||
assign_in_user(&p64->capability, &p32->capability) ||
assign_in_user(&p64->flags, &p32->flags) ||
copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt)))
@ -832,8 +849,7 @@ static int get_v4l2_ext_controls32(struct file *file,
if (aux_space < count * sizeof(*kcontrols))
return -EFAULT;
kcontrols = aux_buf;
if (put_user((__force struct v4l2_ext_control *)kcontrols,
&p64->controls))
if (put_user_force(kcontrols, &p64->controls))
return -EFAULT;
for (n = 0; n < count; n++) {
@ -899,10 +915,9 @@ static int put_v4l2_ext_controls32(struct file *file,
unsigned int size = sizeof(*ucontrols);
u32 id;
if (get_user(id, (unsigned int __user *)&kcontrols->id) ||
if (get_user_cast(id, &kcontrols->id) ||
put_user(id, &ucontrols->id) ||
assign_in_user(&ucontrols->size,
(unsigned int __user *)&kcontrols->size) ||
assign_in_user_cast(&ucontrols->size, &kcontrols->size) ||
copy_in_user(&ucontrols->reserved2,
(void __user *)&kcontrols->reserved2,
sizeof(ucontrols->reserved2)))
@ -971,10 +986,9 @@ static int get_v4l2_edid32(struct v4l2_edid __user *p64,
if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
assign_in_user(&p64->pad, &p32->pad) ||
assign_in_user(&p64->start_block, &p32->start_block) ||
assign_in_user(&p64->blocks,
(u32 __user *)&p32->blocks) ||
assign_in_user_cast(&p64->blocks, &p32->blocks) ||
get_user(tmp, &p32->edid) ||
put_user((void __force *)compat_ptr(tmp), &p64->edid) ||
put_user_force(compat_ptr(tmp), &p64->edid) ||
copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
return -EFAULT;
return 0;