Re: [RFC][PATCH 1/5] exit: kill struct waitid_info

[Oleg Nesterov]

On 07/24, Christian Brauner wrote:
>
> Note that this changes how struct siginfo is filled in for users of
> waitid.

Namely, copy_siginfo_to_user() will nullify the extra SI_EXPANSION_SIZE
bytes + 2*sizeof(__ARCH_SI_CLOCK_T) from _sigchld (waitid doesn't report
utime/stime in siginfo).

Looks correct... even the compat case, but please double-check
copy_siginfo_to_user32/siginfo_layout. Looks like both SIL_KILL and
SIL_CHLD cases are fine in that this patch can't add other user-visible
changes, but I could easily miss something.

> In case
> anyone relies on the old behavior we can just revert

we won't need to rever the whole patch, we can just replace
copy_siginfo_to_user() with copy_to_user(offsetof(si_utime)).

I see you are going to update the changelog and resend, feel free to add
my reviewed-by.

Oleg.