[Bug nptl/13119] New: Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[Bug nptl/13119] New: Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[tavianator at tavianator dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13119

             Bug #: 13119
           Summary: Erroneous "libgcc_s.so.1 must be installed for
                    pthread_cancel to work" message
           Product: glibc
           Version: 2.14
            Status: NEW
          Severity: minor
          Priority: P2
         Component: nptl
        AssignedTo: drepper.fsp@gmail.com
        ReportedBy: tavianator@tavianator.com
    Classification: Unclassified


This is a bit awkward to reproduce, but I found it when attempting to run my
raytracer with a ridiculous number (50,000) of threads.  Here's a reduced
testcase:

$ cat foo.c#include <pthread.h>

void *
bar(void *ptr)
{
  return NULL;
}

void *
foo(void *ptr)
{
  pthread_t thread;
  while (1) {
    if (pthread_create(&thread, NULL, bar, NULL) != 0) {
      pthread_exit(NULL);
    }
  }
  return NULL;
}

int
main()
{
  pthread_t thread;
  pthread_create(&thread, NULL, foo, NULL);
  pthread_join(thread, NULL);
  return 0;
}
$ gcc foo.c -pthread && ./a.out
libgcc_s.so.1 must be installed for pthread_cancel to work

The error comes from nptl/sysdeps/pthread/unwind-forcedunwind.c, which tries to
"__libc_dlopen (LIBGCC_S_SO);".  But in elf/dl-load.c,
_dl_map_object_from_fd(), line 1281, the __mmap() fails with ENOMEM, presumably
because the thousands of zombie threads have left no available memory.  Thus
the dlopen fails, and that message gets printed.

Obviously this isn't a very important issue, but the error message is not
exactly informative, since there's no usage of pthread_cancel() anywhere and
libgcc_s.so.1 is certainly installed.

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[Bug nptl/13119] Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[schwab@linux-m68k.org]

http://sourceware.org/bugzilla/show_bug.cgi?id=13119

Andreas Schwab <schwab@linux-m68k.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|drepper.fsp at gmail dot    |unassigned at sourceware
                   |com                         |dot org

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[Bug nptl/13119] Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13119

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING
                 CC|                            |fweimer at redhat dot com
              Flags|                            |security-

--- Comment #1 from Florian Weimer <fweimer at redhat dot com> ---
Read barriers have been added to the cancellation initialization code.  Can you
check if this fixes this issue?  If it does not, fixing this would have to use
the double-checked locking idiom to prevent duplicating work.

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[Bug nptl/13119] Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[tavianator at tavianator dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13119

--- Comment #2 from Tavian Barnes <tavianator at tavianator dot com> ---
Still reproduces against git glibc from today.

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[Bug nptl/13119] Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13119

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

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[Bug nptl/13119] Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[cliff.atg.linkedin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13119

Cliff Wheatley <cliff.atg.linkedin at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |cliff.atg.linkedin at gmail dot co
                   |                            |m

--- Comment #5 from Cliff Wheatley <cliff.atg.linkedin at gmail dot com> ---
This error "libgcc_s.so.1 must be installed for pthread_cancel to work" is not
repeatable.  It has happened in iconv/tst-gconv-init-failure and
nptl/tst-default-attr.  libgcc_s.so.1 is installed.  Configure invocation
command line was
  $ ../../Source/glibc/configure --prefix=/usr/local/share/glibc-2.33
--enable-bind-now --enable-stack-protector=all
--enable-add-ons=crypt,libidn,linuxthreads --enable-kernel=5.5

It happened both when running "make -j 6 check" and "make check".

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[Bug nptl/13119] Erroneous "libgcc_s.so.1 must be installed for pthread_cancel to work" message

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13119

--- Comment #6 from Florian Weimer <fweimer at redhat dot com> ---
(In reply to Cliff Wheatley from comment #5)
> This error "libgcc_s.so.1 must be installed for pthread_cancel to work" is
> not repeatable.  It has happened in iconv/tst-gconv-init-failure and
> nptl/tst-default-attr.  libgcc_s.so.1 is installed.  Configure invocation
> command line was
>   $ ../../Source/glibc/configure --prefix=/usr/local/share/glibc-2.33
> --enable-bind-now --enable-stack-protector=all
> --enable-add-ons=crypt,libidn,linuxthreads --enable-kernel=5.5

Have you installed libgcc_s.so.1 under /usr/local/share/glibc-2.33?

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