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From: Andreas Schwab <schwab-l3A5Bk7waGM@public.gmane.org>
To: Zack Weinberg <zackw-VmQCmMdMyN0AvxtiuMwx3w@public.gmane.org>
Cc: "H.J. Lu" <hjl.tools-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	"Michael Kerrisk (man-pages)"
	<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	libc-alpha <libc-alpha-9JcytcrH/bA+uJoB2kUjGw@public.gmane.org>,
	linux-man <linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: The time(2) man page conflicts with glibc
Date: Tue, 15 Dec 2015 15:31:23 +0100	[thread overview]
Message-ID: <mvm7fkf941w.fsf@hawking.suse.de> (raw)
In-Reply-To: <CAKCAbMj-X+wLKX3=MDm9z3L9zyikemxCNggu2bfw6=o6K5PGgg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> (Zack Weinberg's message of "Tue, 15 Dec 2015 09:14:36 -0500")

Zack Weinberg <zackw-VmQCmMdMyN0AvxtiuMwx3w@public.gmane.org> writes:

> I did.  The *actual system call* does indeed return -EFAULT when
> memory is invalid, which will be observed as 0xfffffffffffffff2 in the
> return value.  However, the *vDSO shortcut* (which does not trap into
> the kernel) will just segfault the application.  This is an observable
> ABI difference between statically and dynamically linked binaries.

Undefined behaviour can change any time in any way and is not part of
the ABI.

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab-l3A5Bk7waGM@public.gmane.org
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  parent reply	other threads:[~2015-12-15 14:31 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-15 13:58 The time(2) man page conflicts with glibc H.J. Lu
2015-12-15 14:14 ` Zack Weinberg
     [not found]   ` <CAKCAbMj-X+wLKX3=MDm9z3L9zyikemxCNggu2bfw6=o6K5PGgg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-12-15 14:31     ` Andreas Schwab [this message]
2015-12-15 14:55     ` Mike Frysinger
     [not found]       ` <20151215145517.GR11489-UgUKS2FnFs9+urZeOPWqwQ@public.gmane.org>
2015-12-15 15:19         ` Zack Weinberg
     [not found]           ` <CAKCAbMh2ysZPQe3oOSjcPsx1_pcnCAQ6yf+gMbv6iDmvfnGXZA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-12-15 18:38             ` Mike Frysinger
2015-12-16  7:08               ` Rich Felker
     [not found]                 ` <20151216070839.GE238-C3MtFaGISjmo6RMmaWD+6Sb1p8zYI1N1@public.gmane.org>
2015-12-16 20:34                   ` Mike Frysinger
     [not found]                     ` <20151216203432.GR11489-UgUKS2FnFs9+urZeOPWqwQ@public.gmane.org>
2015-12-16 21:59                       ` Rich Felker
     [not found]                         ` <20151216215955.GJ238-C3MtFaGISjmo6RMmaWD+6Sb1p8zYI1N1@public.gmane.org>
2015-12-16 22:27                           ` Zack Weinberg
2015-12-16 22:44                             ` Rich Felker
     [not found]                               ` <20151216224432.GK238-C3MtFaGISjmo6RMmaWD+6Sb1p8zYI1N1@public.gmane.org>
2015-12-16 22:51                                 ` Zack Weinberg
2015-12-17  3:15                           ` Mike Frysinger
     [not found] ` <CAMe9rOoJLk8VzyJKmkOvbmBxhCj4mVA2huYtHJsdxpatbkgJ1g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-12-15 14:16   ` Andreas Schwab
     [not found]     ` <mvmegen94qs.fsf-8jEJWzg51KSXcDkGTvBoYw@public.gmane.org>
2015-12-15 14:17       ` H.J. Lu
2015-12-16 13:38         ` Michael Kerrisk (man-pages)
     [not found]           ` <5671696B.3070203-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-12-16 13:53             ` H.J. Lu
     [not found]               ` <CAMe9rOqsxCEia7OWqzJ-HzZWCra5BTyYqt4japjZTw0pY=fugw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-12-16 14:07                 ` Michael Kerrisk (man-pages)
     [not found]                   ` <56717032.7000007-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-12-16 14:50                     ` Zack Weinberg
     [not found]                       ` <CAKCAbMjrKfsT7P=Q=+1zWC68552aK=ciod0HYk3=HWMvkYW26w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-12-16 15:04                         ` Michael Kerrisk (man-pages)
2015-12-16 23:05                       ` Paul Eggert
     [not found]                         ` <5671EE36.1000402-764C0pRuGfqVc3sceRu5cw@public.gmane.org>
2015-12-17  5:53                           ` Michael Kerrisk (man-pages)

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