Re: [PATCH] override RLIMIT_SIGPENDING for non-RT signals

[Chris Wright]

* Roland McGrath (roland@xxxxxxxxxx) wrote:
> Indeed, I think your patch does not go far enough.  I can read POSIX to say
> that the siginfo_t data must be available when `kill' was used, as well.

How?  I only see reference to filling in SI_USER for rt signals?
Just curious...(I've only got SuSv3 and some crusty old POSIX rt docs).

> This patch makes it allocate the siginfo_t, even when that exceeds
> {RLIMIT_SIGPENDING}, for any non-RT signal (< SIGRTMIN) not sent by
> sigqueue (actually, any signal that couldn't have been faked by a sigqueue
> call).  Of course, in an extreme memory shortage situation, you are SOL and
> violate POSIX a little before you die horribly from being out of memory anyway.

> The LEGACY_QUEUE logic already ensures that, for non-RT signals, at most
> one is ever on the queue.  So there really is no risk at all of unbounded
> resource consumption; the usage can reach {RLIMIT_SIGPENDING} + 31, is all.

Good point.  Although it's RLIMIT_SIGPENDING + (31 * user_nprocs).  So
that could be 31 * 8k, for example.

thanks,
-chris
-- 
Linux Security Modules     http://lsm.immunix.org     http://lsm.bkbits.net
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