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From: Rich Felker <dalias@aerifal.cx>
To: musl@lists.openwall.com
Subject: Re: Compilation error
Date: Sun, 7 Aug 2011 18:05:09 -0400	[thread overview]
Message-ID: <20110807220509.GM132@brightrain.aerifal.cx> (raw)
In-Reply-To: <20110807220025.GL132@brightrain.aerifal.cx>

On Sun, Aug 07, 2011 at 06:00:25PM -0400, Rich Felker wrote:
> > isn't it enough to
> > weakalias(sc_clock_gettime, __vdso_clock_gettime);
> > and then just use __vdso_clock_gettime ?
> > 
> > (so no __cgt etc)
> 
> No, because -Bsymbolic-functions binds it at link-time, or in other
> words, libc.so is intentionally built with no PLT because that makes
> it faster to start, faster to run, and lighter in memory.

By the way, it would be a lot nicer if we could use and rely on
visibility instead of -Bsymbolic-functions, so we could override the
behavior for a few specific functions. However, as far as I can tell
gcc (much less any other compiler) has no way to say "all functions
without explicit visibility should be protected, and all data without
explicit visibility should be default". So to use visibility we'd have
to have hideous attributes all over the place, which is pretty much
unacceptable...

Fortunately -Bsymbolic-functions is a close enough approximation to
what we want, and happens at the linker level instead of the compiler
level, so it's safe to use.

Rich


  reply	other threads:[~2011-08-07 22:05 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-07 18:57 nicolas
2011-08-07 19:36 ` Szabolcs Nagy
2011-08-07 19:34   ` Rich Felker
2011-08-07 19:50     ` Rich Felker
2011-08-07 21:01       ` nicolas
2011-08-07 20:52         ` Rich Felker
2011-08-07 22:09       ` Szabolcs Nagy
2011-08-07 22:00         ` Rich Felker
2011-08-07 22:05           ` Rich Felker [this message]
2011-08-08  7:08           ` Szabolcs Nagy
2011-08-17 10:33             ` Szabolcs Nagy
2011-08-17 13:39               ` Rich Felker
2011-08-17 14:47                 ` Szabolcs Nagy
2011-08-17 14:59                   ` Szabolcs Nagy
2011-08-17 18:18                   ` Rich Felker
2011-08-08 13:03           ` Make nicolas
2011-08-08 20:55             ` Make Rich Felker
2011-08-08 20:56             ` Make Rich Felker
2011-08-09 19:10               ` Make nicolas
2011-08-09 19:29                 ` Make Rich Felker
2011-08-09 20:23                 ` Make Szabolcs Nagy
2011-08-10 19:19                   ` Make nicolas

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