From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: cygwin@cygwin.com
Subject: Re: malloc(0) crashing with SIGABRT
Date: Thu, 12 Sep 2019 03:59:00 -0000 [thread overview]
Message-ID: <749ecff2-e384-bbfe-c961-481157c73052@SystematicSw.ab.ca> (raw)
In-Reply-To: <78e19eb7-956e-cd05-a076-e56ce347bbbe@gmail.com>
On 2019-09-09 11:13, Petr SkoÄÃk wrote:
> There's been a twitter discussion on how different POSIX platforms
> handle malloc(0): https://twitter.com/sortiecat/status/1170697927804817412 .
>
> As for Cygwin, the answer appears to be "not well", but this should be
> easy to fix.
POSIX SUS V4 2018 says:
"RETURN VALUE
Upon successful completion with size not equal to 0, malloc() shall return a
pointer to the allocated space. If size is 0, either:
A null pointer shall be returned [CX] [Option Start] and errno may be set to
an implementation-defined value, [Option End] or
A pointer to the allocated space shall be returned. The application shall
ensure that the pointer is not used to access an object.
Otherwise, it shall return a null pointer [CX] [Option Start] and set errno to
indicate the error. [Option End]"
The second option could be implemented by a pointer to an unmapped page, or a
reference to an inaccessible mmap-ed area length zero.
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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next prev parent reply other threads:[~2019-09-12 3:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-03 9:28 uc_sigmask set in a sigaction signal handler not honored Petr Skočík
2019-04-03 12:16 ` Corinna Vinschen
2019-04-03 12:43 ` Corinna Vinschen
2019-09-09 17:13 ` malloc(0) crashes with SIGABRT Petr Skočík
2019-09-09 18:27 ` malloc(0) crashing " Petr Skočík
2019-09-12 3:59 ` Brian Inglis [this message]
2019-09-12 11:33 ` Kaz Kylheku
2019-09-12 18:05 ` Brian Inglis
2019-09-12 17:38 ` Ken Brown
[not found] ` <e20e38ff-49b1-6472-b0a4-faeee0176a7c@gmail.com>
2019-09-13 13:21 ` Ken Brown
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