Re: [PATCH v7 18/43] instrumented.h: add KMSAN support

youling 257
2022-10-19T20:07:19Z

That is i did,i already test, remove "u64 __tmp…kmsan_unpoison_memory", no help.
i only remove kmsan_copy_to_user, fix my issue.

2022-10-20 4:00 GMT+08:00, Marco Elver <elver@google.com>:
> On Thu, Oct 20, 2022 at 03:29AM +0800, youling 257 wrote:
> [...]
>> > What arch?
>> > If x86, can you try to revert only the change to
>> > instrument_get_user()? (I wonder if the u64 conversion is causing
>> > issues.)
>> >
>> arch x86, this's my revert,
>> https://github.com/youling257/android-mainline/commit/401cbfa61cbfc20c87a5be8e2dda68ac5702389f
>> i tried different revert, have to remove kmsan_copy_to_user.
>
> There you reverted only instrument_put_user() - does it fix the issue?
>
> If not, can you try only something like this (only revert
> instrument_get_user()):
>
> diff --git a/include/linux/instrumented.h b/include/linux/instrumented.h
> index 501fa8486749..dbe3ec38d0e6 100644
> --- a/include/linux/instrumented.h
> +++ b/include/linux/instrumented.h
> @@ -167,9 +167,6 @@ instrument_copy_from_user_after(const void *to, const
> void __user *from,
> */
> #define instrument_get_user(to) \
> ({ \
> - u64 __tmp = (u64)(to); \
> - kmsan_unpoison_memory(&__tmp, sizeof(__tmp)); \
> - to = __tmp; \
> })
>
>
> Once we know which one of these is the issue, we can figure out a proper
> fix.
>
> Thanks,
>
> -- Marco
>