From: Alexander Monakov <amonakov@ispras.ru>
To: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: Paul Eggert <eggert@cs.ucla.edu>, libc-alpha@sourceware.org
Subject: Re: [PATCH v4 1/6] stdlib: Optimization qsort{_r} swap implementation (BZ 19305)
Date: Thu, 13 Jul 2023 16:13:53 +0300 (MSK) [thread overview]
Message-ID: <a57770cf-8c3e-95aa-a61c-04bd42f36f05@ispras.ru> (raw)
In-Reply-To: <9c33143c-c100-225e-0638-ac7a6291a261@linaro.org>
[-- Attachment #1: Type: text/plain, Size: 662 bytes --]
On Thu, 13 Jul 2023, Adhemerval Zanella Netto via Libc-alpha wrote:
> >> + if (is_aligned (pbase, size, sizeof (uint64_t)))
> >> + swap_func = SWAP_WORDS_64;
> >
> > alignof not sizeof, in contexts like these that are talking about alignment not size.
>
> Indeed, I will fix it.
Are you going to use GNU __alignof, or C11 _Alignof? One is safe. The other
makes the code go *boom* on 32-bit x86 when 'size' is 4 modulo 8, coming
this || close to a sneaky singular out-of-bounds write, saved only by the
fact that gcc doesn't (yet) do high-level transforms in swap_words_64.
(the code is not, in fact, talking solely about alignment there)
Alexander
next prev parent reply other threads:[~2023-07-13 13:13 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-11 19:07 [PATCH v4 0/6] Use introsort for qsort Adhemerval Zanella
2023-07-11 19:07 ` [PATCH v4 1/6] stdlib: Optimization qsort{_r} swap implementation (BZ 19305) Adhemerval Zanella
2023-07-11 23:40 ` Noah Goldstein
2023-07-12 19:40 ` Adhemerval Zanella Netto
2023-07-12 21:04 ` Paul Eggert
2023-07-13 11:07 ` Adhemerval Zanella Netto
2023-07-13 13:13 ` Alexander Monakov [this message]
2023-07-13 13:29 ` Adhemerval Zanella Netto
2023-07-11 19:07 ` [PATCH v4 2/6] stdlib: Move insertion sort out qsort Adhemerval Zanella
2023-07-11 23:46 ` Noah Goldstein
2023-07-12 7:28 ` Andreas Schwab
2023-07-12 20:35 ` Adhemerval Zanella Netto
2023-07-11 19:07 ` [PATCH v4 3/6] stdlib: qsort: Move some macros to inline function Adhemerval Zanella
2023-07-11 23:44 ` Noah Goldstein
2023-07-12 20:45 ` Adhemerval Zanella Netto
2023-07-11 19:07 ` [PATCH v4 4/6] stdlib: Implement introsort with qsort Adhemerval Zanella
2023-07-12 5:39 ` Alexander Monakov
2023-07-12 20:55 ` Adhemerval Zanella Netto
2023-07-12 21:55 ` Paul Eggert
2023-07-13 11:53 ` Adhemerval Zanella Netto
2023-07-11 19:07 ` [PATCH v4 5/6] stdlib: Remove use of mergesort on qsort (BZ 21719) Adhemerval Zanella
2023-07-12 22:04 ` Paul Eggert
2023-07-13 11:55 ` Adhemerval Zanella Netto
2023-07-11 19:07 ` [PATCH v4 6/6] stdlib: Add more qsort{_r} coverage Adhemerval Zanella
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