[PATCH] Add missing pthread_condattr_{init,destroy} stubs to libc

[Joe Marcus Clarke]

On Fri, 2009-11-27 at 23:30 +0200, Kostik Belousov wrote:
> On Fri, Nov 27, 2009 at 04:19:38PM -0500, Daniel Eischen wrote:
> > 
> > On Nov 27, 2009, at 2:14 PM, Joe Marcus Clarke <marcus at freebsd.org>  
> > wrote:
> > 
> > >On Fri, 2009-11-27 at 15:12 +0200, Kostik Belousov wrote:
> > >>On Fri, Nov 27, 2009 at 12:15:18AM -0500, Joe Marcus Clarke wrote:
> > >>>I would like permission to commit this patch which adds missing
> > >>>pthread_condattr_{init,destroy} symbols to libc.  I think I did the
> > >>>symbol addition correctly (and it seems to work).  Without this, the
> > >>>weak symbols added in the libpthread-stubs port conflict with  
> > >>>those in
> > >>>libthr, and applications with use these symbols can crash.
> > >>>
> > >>>I have temporarily hacked libpthread-stubs to fix this, but I really
> > >>>feel these stubs should be added to libc.  I've also copied kib as  
> > >>>he
> > >>>has been kind enough to review my work in the past.  Thanks.
> > >>>
> > >>>http://www.marcuscom.com/downloads/stubs.diff
> > >>
> > >>It is FBSD_1.2 version that we use for symbols added after HEAD  
> > >>become
> > >>CURRENT-9.
> > >
> > >Done.
> > 
> > I don't think the symbols belong in FBSD_1.2.  They already exist in  
> > libthr in a previous namespace.  If you use FBSD_1.2, then you  
> > probably need to bump them in libthr and libc_r, and add compatible  
> > symbols (no problem there since there are no differences) for the  
> > previous versions.
> Oh, yes.
> 
> > 
> > Still not sure why libc needs all libpthread stubs.  Shouldn't be  
> > necessary.
> 
> The privately discussed plan for 9.0 is to have libthr merged into
> libc, and have libpthread and libthr as only filter object against libc
> providing pthread_* and related symbols.
> 
> This would eliminate the need for pthread stubs and solve the issues
> with (wrongly built) binaries that do not link to libthr but dlopen()
> libraries that are linked with it.

Yeah, I think that would be a great overall solution.  However, in this
case, the binaries in question ARE linked with -pthread.  The problem
can be easily seen by taking this C program:

#include <sys/time.h>
#include <pthread.h>
#include <string.h>

int
main(void) {
        pthread_condattr_t attr;

        pthread_condattr_init (&attr);
        pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);

        pthread_condattr_destroy (&attr);

        return 0;
}

And compiling it as:

cc -o xxx -L/usr/local/lib -lpthread-stubs -pthread xxx.c

You will need devel/libpthread-stubs (version 0.3) installed.  When you
run it, it will segfault.  If you then rebuild libc and libthr with my
stubs.diff patch, then rebuild libpthread-stubs, the problem will go
away.

Joe

-- 
Joe Marcus Clarke
FreeBSD GNOME Team      ::      gnome at FreeBSD.org
FreeNode / #freebsd-gnome
http://www.FreeBSD.org/gnome
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