On Tue, Apr 26, 2022 at 6:42 PM Alexander Potapenko <glider@xxxxxxxxxx> wrote:
> @@ -99,11 +100,13 @@ extern int __get_user_bad(void);
> int __ret_gu; \
> register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \
> __chk_user_ptr(ptr); \
> + instrument_copy_from_user_before((void *)&(x), ptr, sizeof(*(ptr))); \
> asm volatile("call __" #fn "_%P4" \
> : "=a" (__ret_gu), "=r" (__val_gu), \
> ASM_CALL_CONSTRAINT \
> : "0" (ptr), "i" (sizeof(*(ptr)))); \
> (x) = (__force __typeof__(*(ptr))) __val_gu; \
> + instrument_copy_from_user_after((void *)&(x), ptr, sizeof(*(ptr)), 0); \
Isn't "ptr" the original pointer here? I think what happened with the
reported warning is that you get one output line for every instance this
is used in. There should probably be a
__auto_type __ptr = (ptr);
at the beginning of the macro to ensure that 'ptr' is only evaluated once.
>>> arch/x86/kernel/signal.c:360:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void [noderef] __user *to @@ got unsigned long long [usertype] * @@
It would also make sense to add the missing __user annotation in this line, but
I suspect there are others like it in drivers.
Arnd
