From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Subject: Re: Documenting the (dynamic) linking rules for symbol versioning Date: Fri, 5 May 2017 16:10:47 +0200 Message-ID: <377fb71a-3634-0809-e827-04dab4b7155f@redhat.com> References: <22f26755-f7f0-898a-ac74-3f6df92a22d7@sourceware.org> <2fab9588-2fa6-8c87-da25-be9376c085ea@redhat.com> <89907506-fddb-2429-7e18-b00b8a560070@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael Kerrisk (man-pages)" , siddhesh-9JcytcrH/bA+uJoB2kUjGw@public.gmane.org, "libc-alpha-9JcytcrH/bA+uJoB2kUjGw@public.gmane.org" Cc: linux-man , Carlos O'Donell , Rich Felker , "H.J. Lu" List-Id: linux-man@vger.kernel.org On 04/20/2017 04:09 PM, Michael Kerrisk (man-pages) wrote: > On 04/20/2017 03:45 PM, Florian Weimer wrote: >> On 04/20/2017 03:15 PM, Siddhesh Poyarekar wrote: >>> On Thursday 20 April 2017 06:31 PM, Florian Weimer wrote: >>>>> Hmm interesting, I thought 'latest' would imply the last version in the >>>>> sequence of versions in the map, but I guess it kinda makes sense that >>>>> it is the @@ default, similar to how a static linker would pick it up. >>>> >>>> It might be another instance of bug 12977. At least its fix will >>>> involve preferring the default version in this case. I don't know what >>> >>> From Michael's test case it seems like it already is preferring the >>> default version. The fix would have to be to the comment that says >>> prefer the oldest version for regular unversioned lookups and the >>> *latest* for the dlsym lookups. >>> >>> That or I misunderstood what you said. >> >> I think it picked the default version by accident because of the way the >> linker ordered the list. But I could be mistaken. > > How could I test your hypothesis? Just a longer chain of versions, > maybe? Or oddly named version tags? I'm no longer sure what I actually saw during testing. May be the results also depend on the binutils version. Based on source code inspection in glibc, I think there actually is a problem here, but I can't reproduce it with stock binaries. Thanks, Florian -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html