From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: Re: Use of size_t and ssize_t in mseek
Date: Thu, 27 Jun 2013 12:35:22 +0200 [thread overview]
Message-ID: <20130627103521.GG15323@port70.net> (raw)
In-Reply-To: <20130627042314.GW29800@brightrain.aerifal.cx>
* Rich Felker <dalias@aerifal.cx> [2013-06-27 00:23:14 -0400]:
> some reasonable error, but I still want to find and fix any remaining
> places where objects larger than PTRDIFF_MAX could come into existence
> since they affect other code too, and once those are fixed, the check
> in fmemopen would be obsolete.
>
> As far as I can tell, mmap and maybe shmat are the only functions that
> might be able to make such large objects. Do you know any others?
void *p=sbrk(1<<30); sbrk(1<<30);
or
int main() { char a[1U<<31]; }
it seems compilers dont like objects >=2G size either
(is there a constraint for this in the standard?
gcc even fails if the sum of the local objects are >=2G,
but tcc, pcc generates code in that case)
i assume isoc would not allow this but you can concatenate
address ranges:
char *p,*q;
q = mmap(0, 1<<30, prot, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
p = mmap(q-(1<<30), 1<<30, prot, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if (p && q && p == q-(1<<30)) {
now p points to a 2G continous address range
you could even mprotect(p, 1U<<31, prot);
next prev parent reply other threads:[~2013-06-27 10:35 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-27 3:52 Matthew Fernandez
2013-06-27 4:10 ` Rich Felker
2013-06-27 4:16 ` Matthew Fernandez
2013-06-27 4:23 ` Rich Felker
2013-06-27 4:31 ` Matthew Fernandez
2013-06-27 15:34 ` Rich Felker
2013-06-28 0:49 ` Matthew Fernandez
2013-06-28 1:22 ` Rich Felker
2013-06-28 1:34 ` Matthew Fernandez
2013-06-28 1:48 ` Rich Felker
2013-06-28 1:56 ` Matthew Fernandez
2013-06-29 4:13 ` Rich Felker
2013-06-29 13:38 ` Matthew Fernandez
2013-06-29 14:17 ` Rich Felker
2013-06-29 14:56 ` Jens Gustedt
2013-06-29 15:48 ` Rich Felker
2013-06-29 16:01 ` Jens Gustedt
2013-06-29 16:13 ` Rich Felker
2013-06-29 16:39 ` Jens Gustedt
2013-07-04 1:28 ` Rich Felker
2013-07-04 6:11 ` Jens Gustedt
2013-07-04 6:37 ` Rich Felker
2013-07-04 7:11 ` Jens Gustedt
2013-07-04 8:12 ` Rich Felker
2013-07-04 8:45 ` Jens Gustedt
2013-07-04 15:24 ` Rich Felker
2013-07-04 11:10 ` Szabolcs Nagy
2013-07-04 11:58 ` Jens Gustedt
2013-07-04 15:26 ` Rich Felker
2013-06-27 10:35 ` Szabolcs Nagy [this message]
2013-06-27 15:05 ` Rich Felker
2013-06-27 16:47 ` Rich Felker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130627103521.GG15323@port70.net \
--to=nsz@port70.net \
--cc=musl@lists.openwall.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/musl/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).