Russ Cox wrote:
>> Yes, that makes sense. These functions just check for the annotation on their
>> pointer argument, and having the const annotation would allow them to check
>> const pointers without provoking a warning due to the lack of const.
>
> They don't provoke a warning now. Sparse is silent on this program:
>
> #define __user __attribute__((noderef, address_space(1)))
>
> extern void __chk_user_ptr(void __user *);
>
> void
> f(const void __user *p)
> {
> __chk_user_ptr(p);
> }
Hmmm, odd. After a few iterations, I managed to discover that Sparse will
warn if you attempt to convert a const int * to an int *, but not if you
attempt to convert a const void * to a void *. This seems like a bug to me.
> but arguably they should (and then be changed to const void __user*).
Yes. Please do go ahead and propose the obvious const-adding patch to
include/linux/compiler.h, Cc linux-sparse, and feel free to add a
Signed-off-by from me.
- Josh Triplett
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