Re: [RFC] Get siginfo from unreaped task

[Robert Święcki]

sob., 12 lut 2022 o 05:28 Kees Cook <keescook@xxxxxxxxxxxx> napisał(a):
>
> Make siginfo available through PTRACE_GETSIGINFO after process death,
> without needing to have already used PTRACE_ATTACH. Uses 48 more bytes
> in task_struct, though I bet there might be somewhere else we could
> stash a copy of it?

An alternative way of accessing this info could be abusing the
waitid() interface, with some additional, custom to Linux, flag

waitid(P_ALL, 0, &si, __WCHILDSIGINFO);

which would change what is put into si.

But maybe ptrace() is better, because it's mostly incompatible with
other OSes anyway on the behavior/flag level, while waitd() seems to
be POSIX/BSD standard, even if Linux specifies some additional flags.

-- 
Robert Święcki