On 1/15/20 9:35 AM, Eugene Syromiatnikov wrote:
> fds field of struct io_uring_files_update is problematic with regards
> to compat user space, as pointer size is different in 32-bit, 32-on-64-bit,
> and 64-bit user space. In order to avoid custom handling of compat in
> the syscall implementation, make fds __u64 and use u64_to_user_ptr in
> order to retrieve it. Also, align the field naturally and check that
> no garbage is passed there.
Good point, it's an s32 pointer so won't align nicely. But how about
just having it be:
struct io_uring_files_update {
__u32 offset;
__u32 resv;
__s32 *fds;
};
which should align nicely on both 32 and 64-bit?
--
Jens Axboe
