Re: [PATCH] Use correct type for glibc.malloc.perturb in tst-tunconf1.c

"Andreas K. Huettel" <[email protected]> Sun, 12 Jul 2026 21:56:01 +0900

Newsgroups	gmane.comp.lib.glibc.alpha
Organization	Gentoo Linux
Message-ID	<[email protected]>

Am Samstag, 11. Juli 2026, 01:35:30 Japanische Normalzeit schrieb DJ Delorie:
> Stefan Liebler <[email protected]> writes:
> > According to elf/dl-tunables.list, glibc.malloc.perturb is of type
> > int32_t (4byte) and not size_t (8byte) which was used for
> > TUNABLE_GET_FULL inside the testcase.  Therefore the correct 32bit
> > value 0x2a=42 is written to the to the wrong place and leads to the
> > comparison failure.
> 
> I'm wondering how it passed for me...  does it only show up on MSB systems?

I only saw it on s390x too.

> 
> > +  printf("perturb is %d (should be 42, from /etc)\n",
> > +	 perturb);
> 
> Do we know that %d matches int32_t on all platforms?  Or should we cast
> this to (int) ?

Best I could find in a draft of the C standard floating on the internets, 
in the section on fprintf %d is specified to be of type int.

Which is, to my best knowledge, 32bit everywhere we can run Linux.

> 
> 


-- 
PD Dr. Andreas K. Hüttel
[email protected]
Gentoo Linux developer 
(council, comrel, toolchain, base-system, perl, libreoffice)
https://wiki.gentoo.org/wiki/User:Dilfridge

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