Files
kernel_arpi/include/linux
Arnd Bergmann 8896dd968b compat_ioctl: add compat_ptr_ioctl()
commit 2952db0fd5 upstream.

Many drivers have ioctl() handlers that are completely compatible between
32-bit and 64-bit architectures, except for the argument that is passed
down from user space and may have to be passed through compat_ptr()
in order to become a valid 64-bit pointer.

Using ".compat_ptr = compat_ptr_ioctl" in file operations should let
us simplify a lot of those drivers to avoid #ifdef checks, and convert
additional drivers that don't have proper compat handling yet.

On most architectures, the compat_ptr_ioctl() just passes all arguments
to the corresponding ->ioctl handler. The exception is arch/s390, where
compat_ptr() clears the top bit of a 32-bit pointer value, so user space
pointers to the second 2GB alias the first 2GB, as is the case for native
32-bit s390 user space.

The compat_ptr_ioctl() function must therefore be used only with
ioctl functions that either ignore the argument or pass a pointer to a
compatible data type.

If any ioctl command handled by fops->unlocked_ioctl passes a plain
integer instead of a pointer, or any of the passed data types is
incompatible between 32-bit and 64-bit architectures, a proper handler
is required instead of compat_ptr_ioctl.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-17 19:55:30 +01:00
..
2019-09-17 10:27:46 -07:00
2019-09-16 09:56:27 -07:00
2019-11-29 10:10:10 +01:00
2019-08-28 21:17:12 -06:00
2019-09-05 19:52:33 -06:00
2019-12-17 19:55:30 +01:00
2019-11-29 10:10:13 +01:00
2019-09-05 11:40:54 +02:00
2019-09-24 15:54:08 -07:00
2019-10-02 06:36:50 -07:00
2019-09-07 04:28:05 -03:00
2019-12-13 08:42:53 +01:00
2019-09-02 11:43:54 +01:00
2019-09-05 12:32:05 +02:00
2019-12-13 08:43:18 +01:00
2019-10-04 18:11:08 -07:00
2019-08-23 16:39:26 +01:00
2019-11-29 10:10:13 +01:00
2019-10-31 14:01:40 -07:00
2019-09-25 17:51:41 -07:00
2019-09-07 21:42:25 +02:00
2019-10-02 10:06:45 +02:00
2019-08-30 07:27:17 -07:00
2019-10-14 15:04:01 -07:00