From: Pedro Alves <palves@redhat.com>
To: Jeff Law <law@redhat.com>, Aldy Hernandez <aldyh@redhat.com>,
gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: protected alloca class for malloc fallback
Date: Thu, 04 Aug 2016 19:22:00 -0000 [thread overview]
Message-ID: <348e247a-f015-ef7a-52f3-3387610c0836@redhat.com> (raw)
In-Reply-To: <05d31d84-0393-58b1-1491-e5e9b3da78d5@redhat.com>
On 08/04/2016 08:16 PM, Jeff Law wrote:
> On 08/04/2016 01:06 PM, Pedro Alves wrote:
>> How wedded are we to alloca?
> I would think only in the sense of existing codebase usage.
>
> Based on how often alloca usage has resulted in a security vulnerability
> it's clear we as developers can't use it correctly on a consistent
> basis, thus I'd like to abolish it :-) I'll settle for warning folks
> when they use it incorrectly though.
Most allocas I've seen in my life were written to simply build
strings at run time, while lazily avoiding to think about writing
a "free" call, rather than having been written for optimizing
some fast path, or for async-signal safe reasons.
My guess is that auto_vec<char, MAX_ALLOCA_SIZE> covers any
fast-path-handling requirement in gcc.
(Where alloca is being used for async-signal safely reasons you
can't have a malloc fallback anyway, so out of scope for the
proposed protected_alloca too.)
Thanks,
Pedro Alves
next prev parent reply other threads:[~2016-08-04 19:22 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-04 11:30 Aldy Hernandez
2016-08-04 12:58 ` Richard Biener
2016-08-04 15:19 ` Aldy Hernandez
2016-08-04 19:24 ` Jeff Law
2016-08-05 14:37 ` Aldy Hernandez
2016-08-05 15:15 ` Pedro Alves
2016-08-05 16:23 ` Jeff Law
2016-08-05 17:48 ` Richard Biener
2016-08-05 8:17 ` Richard Biener
2016-08-04 19:06 ` Pedro Alves
2016-08-04 19:16 ` Jeff Law
2016-08-04 19:22 ` Pedro Alves [this message]
2016-08-04 19:26 ` Jeff Law
2016-08-04 19:31 ` Pedro Alves
2016-08-05 2:10 ` Martin Sebor
2016-08-05 14:42 ` Aldy Hernandez
2016-08-05 17:56 ` Richard Biener
2016-08-05 18:16 ` Oleg Endo
2016-08-05 20:07 ` Richard Biener
2016-08-06 10:09 ` Aldy Hernandez
2016-08-06 10:15 ` Aldy Hernandez
2016-08-06 15:08 ` Richard Biener
2016-08-08 17:00 ` Jeff Law
2016-08-08 17:32 ` Trevor Saunders
2016-08-08 19:03 ` Richard Biener
2016-08-09 11:34 ` Oleg Endo
2016-08-09 17:34 ` Trevor Saunders
2016-08-10 17:03 ` Oleg Endo
2016-08-11 1:23 ` Trevor Saunders
2016-08-11 12:18 ` Oleg Endo
2016-08-11 17:55 ` Trevor Saunders
2016-08-20 2:29 ` Mike Stump
2016-08-21 20:00 ` C++11? (Re: protected alloca class for malloc fallback) Pedro Alves
2016-08-22 7:10 ` Trevor Saunders
2016-08-22 7:28 ` Richard Biener
2016-08-22 12:02 ` Eric Gallager
2016-08-22 12:58 ` Manuel López-Ibáñez
2016-08-22 22:08 ` Mike Stump
2016-08-23 23:17 ` Eric Gallager
2016-08-09 13:17 ` protected alloca class for malloc fallback Aldy Hernandez
2016-08-09 13:21 ` Bernd Schmidt
2016-08-10 10:04 ` Richard Biener
2016-08-10 10:12 ` Aldy Hernandez
2016-08-10 10:39 ` Richard Biener
2016-08-10 18:00 ` Jeff Law
2016-08-10 18:33 ` Richard Biener
2016-08-16 16:28 ` Jeff Law
2016-08-16 16:44 ` Jakub Jelinek
2016-08-16 16:47 ` Jeff Law
2016-08-16 17:54 ` Martin Sebor
2016-08-17 8:27 ` Richard Biener
2016-08-17 13:39 ` Martin Sebor
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