Michal Suchánek's on April 3, 2020 8:52 pm:

Hello,

there are 3 variants of the function

read_user_stack_64

32bit read_user_stack_32
64bit read_user_Stack_32

Right.

On Fri, Apr 03, 2020 at 05:13:25PM +1000, Nicholas Piggin wrote:

[...]

quoted

 #endif /* CONFIG_PPC64 */
 
+static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
+{
+	return __read_user_stack(ptr, ret, sizeof(*ret));

Does not work for 64bit read_user_stack_32 ^ this should be 4.

Other than that it should preserve the existing logic just fine.

sizeof(int) == 4 on 64bit so it should work.

Thanks,
Nick