[PATCH 0/3] Linux: Keep termios ioctl constants strictly internal

[H. Peter Anvin]

On July 15, 2025 8:23:17 AM PDT, Andreas Schwab <schwab@suse.de> wrote:
>On Jul 15 2025, H. Peter Anvin wrote:
>
>> On July 15, 2025 12:39:06 AM PDT, Andreas Schwab <schwab@suse.de> wrote:
>>>On Jul 14 2025, H. Peter Anvin wrote:
>>>
>>>> When this was first discussed I suggested that the Right Thing for the
>>>> sanitizer to do is to use <linux/ioctl.h> and <linux/termios.h> instead of
>>>> <sys/ioctl.h> and <termios.h>, because what the sanitizer is looking for
>>>> (in this case) is specifically the kernel ABIs.
>>>
>>>But the sanitizer intercepts libc, not syscalls.
>>>
>>
>> It does, but ioctl(3) is basically ioctl(2), much like intercepting syscall(3).
>
>Since it intercepts the libc wrapper, it needs to use the ioctl numbers
>that libc uses.
>

There are exactly four ioctls intercepted by Linux glibc, and only on the PowerPC platform. The error of using the libc headers is vastly higher than the converse would be.