From: Zack Weinberg via Libc-alpha <libc-alpha@sourceware.org>
To: libc-alpha@sourceware.org
Subject: Re: [RFC] Supporting malloc_usable_size
Date: Mon, 5 Dec 2022 13:46:08 -0500 [thread overview]
Message-ID: <5758633c-9989-e463-0eb6-33f483439289@owlfolio.org> (raw)
In-Reply-To: <87pmd2rnce.fsf@oldenburg.str.redhat.com>
On 2022-12-02 7:39 AM, Florian Weimer via Libc-alpha wrote:
> * Andreas Schwab:
>
>> On Dez 02 2022, Siddhesh Poyarekar wrote:
>>
>>> However the man page starts with "Although the excess bytes can be
>>> overwritten by the application without ill effects" and maybe that
>>> reassurance needs to be dropped.
>>
>> Or perhaps amended: "until the next call to malloc/realloc/free in any
>> thread".
>
> The list will never be complete because glibc can call into the malloc
> subsystem internally
How about this then? "The excess bytes, if any, are only guaranteed to
exist until the next call to malloc/realloc/free in any thread. Note
that almost all C library functions are allowed to use malloc internally
for scratch space, and the list of functions that do so may change
without notice. Only the functions documented as async-signal-safe are
guaranteed not to use malloc internally."
> or even spontaneously from an internal service thread
We don't have any of those now, do we? I'm inclined to say that we
_shouldn't_ have any of those.
zw
next prev parent reply other threads:[~2022-12-05 18:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-24 21:32 [RFC] Supporting malloc_usable_size Siddhesh Poyarekar
2022-12-02 4:42 ` DJ Delorie via Libc-alpha
2022-12-02 5:00 ` Sam James via Libc-alpha
2022-12-02 5:28 ` DJ Delorie via Libc-alpha
2022-12-02 12:36 ` Siddhesh Poyarekar
2022-12-02 19:16 ` DJ Delorie via Libc-alpha
2022-12-02 19:49 ` Siddhesh Poyarekar
2022-12-02 19:57 ` DJ Delorie via Libc-alpha
2022-12-02 12:03 ` Andreas Schwab
2022-12-02 12:22 ` Siddhesh Poyarekar
2022-12-02 12:34 ` Andreas Schwab
2022-12-02 12:39 ` Florian Weimer via Libc-alpha
2022-12-05 18:46 ` Zack Weinberg via Libc-alpha [this message]
2022-12-05 19:04 ` Siddhesh Poyarekar
2022-12-05 20:35 ` Florian Weimer via Libc-alpha
2022-12-06 19:25 ` Siddhesh Poyarekar
2022-12-07 10:01 ` Florian Weimer via Libc-alpha
2022-12-07 16:34 ` Siddhesh Poyarekar
2022-12-07 16:54 ` Adhemerval Zanella Netto via Libc-alpha
2022-12-07 16:57 ` Sam James via Libc-alpha
2022-12-07 17:39 ` Florian Weimer via Libc-alpha
2022-12-09 15:42 ` Siddhesh Poyarekar
2022-12-07 18:45 ` DJ Delorie via Libc-alpha
2022-12-02 12:54 ` Florian Weimer via Libc-alpha
-- strict thread matches above, loose matches on Subject: below --
2022-12-02 13:54 Wilco Dijkstra via Libc-alpha
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