[email protected] (Eric W. Biederman) wrote:
>
> > Sounds sane. We could make it warn if typeof(x)!=typeof(*ptr) by adding
> > another temporary for the pointer, give it type typeof(x)*, but I haven't
> > tried it.
>
> I guess we could do that. However if we don't use the value we will probably
> get an unused variable warning.
No, that's OK, we can use the temporary.
Something like this:
--- devel/include/asm-i386/uaccess.h~x86-tighten-uaccess-type-checking 2006-01-28 23:45:16.000000000 -0800
+++ devel-akpm/include/asm-i386/uaccess.h 2006-01-28 23:48:31.000000000 -0800
@@ -149,14 +149,16 @@ extern void __get_user_4(void);
#define get_user(x,ptr) \
({ int __ret_gu; \
unsigned long __val_gu; \
+ __typeof__(x)*_p_; \
+ _p_ = ptr; \
__chk_user_ptr(ptr); \
- switch(sizeof (*(ptr))) { \
- case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
- case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
- case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
- default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \
+ switch(sizeof (*(_p_))) { \
+ case 1: __get_user_x(1, __ret_gu, __val_gu, _p_); break; \
+ case 2: __get_user_x(2, __ret_gu, __val_gu, _p_); break; \
+ case 4: __get_user_x(4, __ret_gu, __val_gu, _p_); break; \
+ default: __get_user_x(X, __ret_gu, __val_gu, _p_); break; \
} \
- (x) = (__typeof__(*(ptr)))__val_gu; \
+ (x) = __val_gu; \
__ret_gu; \
})
@@ -198,13 +200,17 @@ extern void __put_user_8(void);
#define put_user(x,ptr) \
({ int __ret_pu; \
__chk_user_ptr(ptr); \
- __typeof__(*(ptr)) __pu_val = x; \
+ __typeof__(x)*_p_; \
+ __typeof__(x)__pu_val; \
+ \
+ _p_ = ptr; \
+ __pu_val = x; \
switch(sizeof(*(ptr))) { \
- case 1: __put_user_1(__pu_val, ptr); break; \
- case 2: __put_user_2(__pu_val, ptr); break; \
- case 4: __put_user_4(__pu_val, ptr); break; \
- case 8: __put_user_8(__pu_val, ptr); break; \
- default:__put_user_X(__pu_val, ptr); break; \
+ case 1: __put_user_1(__pu_val, _p_); break; \
+ case 2: __put_user_2(__pu_val, _p_); break; \
+ case 4: __put_user_4(__pu_val, _p_); break; \
+ case 8: __put_user_8(__pu_val, _p_); break; \
+ default:__put_user_X(__pu_val, _p_); break; \
} \
__ret_pu; \
})
_
It gives ~100 warnings on my usual test config. It's a bit awkward because
get_user/put_user/etc aren't allowed to evaluate their args multiple times
- code likes to do
get_user(v, p++);
I guess fixing those 100-odd warnings might find some warts -
compiler-caused truncation or sign-extension during uaccess copies is a bit
of a worry.
But I have enough things to be going on with :(
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
