path: root/open_issues/glibc.mdwn

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[[!tag open_issue_glibc]]

Here's what's to be done for maintaining glibc.

[[!toc levels=2]]


# [[General information|/glibc]]


# [[Sources|source_repositories/glibc]]


# [[Debian]] Cheat Sheet


# Configuration

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git log --reverse --pretty=fuller --stat=$COLUMNS,$COLUMNS -w -p -C --cc ..sourceware/master
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Last reviewed up to the [[Git mirror's d3bd58cf0a027016544949ffd27300ac5fb01bb8
(2012-11-03) sources|source_repositories/glibc]].

  * `t/hurdsig-fixes`

        hurdsig.c: In function '_hurd_internal_post_signal':
        hurdsig.c:1188:26: warning: 'pending' may be used uninitialized in this function [-Wmaybe-uninitialized]
        hurdsig.c:1168:12: note: 'pending' was declared here

  * `t/host-independency`

    [[!message-id "87bougerfb.fsf@kepler.schwinge.homeip.net"]], [[!message-id
    "20120525202732.GA31088@intel.com"]], commit
    918b56067a444572f1c71b02f18255ae4540b043.  [[!GCC_PR 53183]], GCC commit
    c05436a7e361b8040ee899266e15bea817212c37.

  * `t/pie-sbrk`

    [[gcc/PIE]].

  * `t/sysvshm`

        ../sysdeps/mach/hurd/shmat.c: In function '__shmat':
        ../sysdeps/mach/hurd/shmat.c:57:7: warning: implicit declaration of function '__close' [-Wimplicit-function-declaration]
        ../sysdeps/mach/hurd/shmget.c: In function 'get_exclusive':
        ../sysdeps/mach/hurd/shmget.c:85:8: warning: variable 'is_private' set but not used [-Wunused-but-set-variable]
        ../sysdeps/mach/hurd/shmget.c:102:8: warning: 'dir' may be used uninitialized in this function [-Wmaybe-uninitialized]
        ../sysdeps/mach/hurd/shmget.c:102:8: warning: 'file' may be used uninitialized in this function [-Wmaybe-uninitialized]

  * [[`t/tls`|t/tls]]

  * [[`t/tls-threadvar`|t/tls-threadvar]]

  * t/verify.h

    People didn't like this too much.

    Other examples:

      * 11988f8f9656042c3dfd9002ac85dff33173b9bd -- `static_assert`

  * [[toolchain/cross-gnu]], without `--disable-multi-arch`

        i686-pc-gnu-gcc ../sysdeps/i386/i686/multiarch/strcmp.S -c [...]
        ../sysdeps/i386/i686/multiarch/../strcmp.S: Assembler messages:
        ../sysdeps/i386/i686/multiarch/../strcmp.S:31: Error: symbol `strcmp' is already defined
        make[2]: *** [/media/boole-data/thomas/tmp/gnu-0/src/glibc.obj/string/strcmp.o] Error 1
        make[2]: Leaving directory `/media/boole-data/thomas/tmp/gnu-0/src/glibc/string'

    Might simply be a missing patch(es) from master.

  * `--disable-multi-arch`

    IRC, freenode, #hurd, 2012-11-22

        <pinotree> tschwinge: is your glibc build w/ or w/o multiarch?
        <tschwinge> pinotree: See open_issues/glibc: --disable-multi-arch
        <pinotree> ah, because you do cross-compilation?
        <tschwinge> No, that's natively.
        <tschwinge> There is also a not of what happened in cross-gnu when I
          enabled multi-arch.
        <tschwinge> No idea whether that's still relevant, though.
        <pinotree> EPARSE
        <tschwinge> s%not%note
        <tschwinge> Better?
        <pinotree> yes :)
        <tschwinge> As for native builds: I guess I just didn't (want to) play
          with it yet.
        <pinotree> it is enabled in debian since quite some time, maybe other
          i386/i686 patches (done for linux) help us too
        <tschwinge> I though we first needed some CPU identification
          infrastructe before it can really work?
        <tschwinge> I thought [...].
        <pinotree> as in use the i686 variant as runtime automatically? i guess
          so
        <tschwinge> I thought I had some notes about that, but can't currently
          find them.
        <tschwinge> Ah, I probably have been thinking about open_issues/ifunc
          and open_issues/libc_variant_selection.

  * --build=X

    `long double` test: due to `cross_compiling = maybe` wants to execute a
    file, which fails.  Thus `--build=X` has to be set.

  * Check what all these are:

        running configure fragment for sysdeps/mach/hurd
        checking Hurd header version... ok
        running configure fragment for sysdeps/mach
        checking for i586-pc-gnu-mig... i586-pc-gnu-mig
        checking for mach/mach_types.h... yes
        checking for mach/mach_types.defs... yes
        checking for task_t in mach/mach_types.h... task_t
        checking for thread_t in mach/mach_types.h... thread_t
        checking for creation_time in task_basic_info... yes
        checking for mach/mach.defs... yes
        checking for mach/mach4.defs... yes
        checking for mach/clock.defs... no
        checking for mach/clock_priv.defs... no
        checking for mach/host_priv.defs... no
        checking for mach/host_security.defs... no
        checking for mach/ledger.defs... no
        checking for mach/lock_set.defs... no
        checking for mach/processor.defs... no
        checking for mach/processor_set.defs... no
        checking for mach/task.defs... no
        checking for mach/thread_act.defs... no
        checking for mach/vm_map.defs... no
        checking for mach/memory_object.defs... yes
        checking for mach/memory_object_default.defs... yes
        checking for mach/default_pager.defs... yes
        checking for mach/i386/mach_i386.defs... yes
        checking for egrep... grep -E
        checking for host_page_size in mach_host.defs... no
        checking for mach/machine/ndr_def.h... no
        checking for machine/ndr_def.h... no
        checking for i386_io_perm_modify in mach_i386.defs... yes
        checking for i386_set_gdt in mach_i386.defs... yes
        checking whether i586-pc-gnu-mig supports the retcode keyword... yes

  * `sysdeps/i386/stackguard-macros.h`

    See [[t/tls|t/tls]].

  * Verify 77c84aeb81808c3109665949448dba59965c391e against
    `~/shared/glibc/make_TAGS.patch`.

  * `HP_SMALL_TIMING_AVAIL` not defined anywhere.

  * Unify `CPUCLOCK_WHICH` stuff in `clock_*` files.

  * Not all tests are re-run in a `make -k tests; make tests-clean; make -k
    tests` cycle.  For example, after `make tests-clean`:

        $ find ./ -name \*.out
        ./localedata/tst-locale.out
        ./localedata/sort-test.out
        ./localedata/de_DE.out
        ./localedata/en_US.out
        ./localedata/da_DK.out
        ./localedata/hr_HR.out
        ./localedata/sv_SE.out
        ./localedata/tr_TR.out
        ./localedata/fr_FR.out
        ./localedata/si_LK.out
        ./localedata/tst-mbswcs.out
        ./iconvdata/iconv-test.out
        ./iconvdata/tst-tables.out
        ./stdlib/isomac.out
        ./posix/wordexp-tst.out
        ./posix/annexc.out
        ./posix/tst-getconf.out
        ./elf/check-textrel.out
        ./elf/check-execstack.out
        ./elf/check-localplt.out
        ./c++-types-check.out
        ./check-local-headers.out
        ./begin-end-check.out

  * `CPUCLOCK_WHICH`, `t/cpuclock`

        /media/boole-data/thomas/tmp/gnu-0/src/glibc.obj/rt/librt_pic.a(clock_settime.os): In function `clock_settime':
        /media/boole-data/thomas/tmp/gnu-0/src/glibc/rt/../sysdeps/unix/clock_settime.c:113: undefined reference to `CPUCLOCK_WHICH'
        /media/boole-data/thomas/tmp/gnu-0/src/glibc/rt/../sysdeps/unix/clock_settime.c:114: undefined reference to `CPUCLOCK_WHICH'
        collect2: error: ld returned 1 exit status
        make[2]: *** [/media/boole-data/thomas/tmp/gnu-0/src/glibc.obj/rt/librt.so] Error 1
        make[2]: Leaving directory `/media/boole-data/thomas/tmp/gnu-0/src/glibc/rt'
        make[1]: *** [rt/others] Error 2
        make[1]: Leaving directory `/media/boole-data/thomas/tmp/gnu-0/src/glibc'
        make: *** [all] Error 2

  * Missing interfaces, amongst many more.

    Many more are missing, some of which have been announced in `NEWS`, others
    typically haven't (like new flags to existing functions).  Typically,
    porters will notice missing functionaly.  But in case you're looking for
    something to work on, here's a list.

    `AT_EMPTY_PATH`, `CLOCK_BOOTTIME`, `CLOCK_BOOTTIME_ALARM`,
    `CLOCK_REALTIME_ALARM`, `O_PATH`,
    `PTRACE_*` (for example, cbff0d9689c4d68578b6a4f0a17807232506ea27,
    b1b2aaf8eb9eed301ea8f65b96844568ca017f8b),
    `RLIMIT_RTTIME`, `SEEK_DATA` (`unistd.h`), `SEEK_HOLE` (`unistd.h`)
    `clock_adjtime`, `fallocate`, `fallocate64`, `name_to_handle_at`,
    `open_by_handle_at`, `process_vm_readv`, `process_vm_writev`, `sendmmsg`,
    `setns`, `sync_file_range`, [[`mremap`|mremap]] and [[several
    `MAP_*`|glibc/mmap]]

    Check also the content of `gnu/stubs.h`, which lists all the functions
    marked as stub which only return `ENOSYS`.

      * `chflags`

        Patch sent, [[!message-id "20120427012130.GZ19431@type.famille.thibault.fr"]].

        IRC, OFTC, #debian-hurd, 2012-04-27:

            <Steap> Does anyone have any idea why int main(void) { return
              chflags(); } will compile with gcc but not with g++ ? It says
              that "chflags" was not declared in this scope.
            <Steap> I get the same error on FreeBSD, but including sys/stat.h
              makes it work
            <Steap> Can't find a solution on Hurd though :/
            <youpi> the Hurd doesn't have chflags
            <youpi> apparently linux neither
            <youpi> what does it do?
            <Steap> change flags :)
            <Steap> Are you sure the Hurd does not have chflags ? Because gcc
              does not complain
            <youpi> there is no chflags function in /usr/include
            <youpi> but what flags does it change?
            <Steap> According to the FreeBSD manpage, it can set flags such as
              UF_NODUMP, UF_IMMUTABLE etc.
            <youpi> Hum, there is actually a chflags() definition
            <youpi> but no declaration
            <youpi> so actually chflags is supported, but the declaration was
              forgotten
            <youpi> probably because since linux doens't have it, it has never
              been a problem up to now
            <youpi> so I'd say ignore the error for now, we'll add the
              declaration

      * `getcontext`/`setcontext`

        Needed for [[gccgo]].

        IRC, freenode, #hurd, 2012-04-19:

            <gnu_srs> How much work/knowledge is needed to implement
              getcontext/setcontext?
            <gnu_srs> Any already implemented alternatives available?
            <youpi> x86 registers knowledge, as well as unix signal masks
            <youpi> there's the linux implementation that can be taken as an
              exxample, but the signal part has to be rewritten
            <gnu_srs> Well, it's a pity they are not implemented. That's the
              remaining hurdle to get gccgo working :-( 
            <youpi> uh :/
            <gnu_srs> Everything builds, but the testsuite fails due to these
              missing functions.
            <gnu_srs> Regarding getcontext/setcontext they seem to be written
              in assembly for linux but the code is not very long. 
            <gnu_srs> How much effort would it be to write something similar
              for Hurd? Anybody fluent in asm?
            <gnu_srs> And registers and signals.
            <tschwinge> gnu_srs: Signals is the key thing -- everything else we
              can probably just copy.  I have never/not yet looked at it,
              though.
            <gnu_srs> For kfreebsd it is written in C: kern_context.c, 3/4 in
              one file: getcontext, setcontext,  swapcontext, not makecontext.
            <gnu_srs> Dunno how much assembly calls used though.
            <gnu_srs> Hi, any preferences about implementing get/setcontext in
              C or Asm?
            <tschwinge> gnu_srs: I think these will have to be implemented in
              assembly.  Based on the Linux x86 variants.

        IRC, freenode, #hurd, 2012-04-20:

            <tschwinge> youpi: Your understanding of that is better than mine
              -- the *context stuff can't be very useful at the moment, because
              when the user changes uc_stack.ss_sp (which the glibc tests are
              doing), we're losing access to the _hurd_threadvars.  Correct?
            <tschwinge> At least the getcontext test works, the other get a
              SIGILL.
            <tschwinge> others
            <tschwinge> _hurd_threadvars issue is just guessing.
            <youpi> tschwinge: yes, threadvars are on the stack
            <youpi> threadvars is not much code, it should just work, but care
              has to be taken on the libpthread/libthread side, which does some
              initialization
            <tschwinge> OK, that at least matches my understanding.

      * `futimesat`

        If we have all of 'em (check Linux kernel), `#define __ASSUME_ATFCTS`.

      * `bits/stat.h [__USE_ATFILE]`: `UTIME_NOW`, `UTIME_OMIT`

      * `io/fcntl.h [__USE_ATFILE]`

        Do we support `AT_FDCWD` et al.?
        (80b4e5f3ef231702b24d44c33e8dceb70abb3a06.)

      * `t/opendirat`: `opendirat` (`scandirat`, `scandirat64`)

        Need changes equivalent to c55fbd1ea768f9fdef34a01377702c0d72cbc213 +
        14d96785125abee5e9a49a1c3037f35a581750bd.

      * `madvise`, `MADV_DONTNEED`, `MADV_DONTDUMP`, `MADV_DODUMP`

        [[glibc_madvise_vs_static_linking]].

      * `msync`

        Then define `_POSIX_MAPPED_FILES`, `_POSIX_SYNCHRONIZED_IO`.

      * `sys/epoll.h`

        Used by [[wayland]], for example.

      * `sys/eventfd.h`

      * `sys/inotify.h`

      * `sys/signalfd.h`

      * `sys/timerfd.h`

      * `timespec_get` (74033a2507841cf077e31221de2481ff30b43d51)

      * `waitflags.h` (`WEXITED`, `WNOWAIT`, `WSTOPPED`, `WCONTINUED`)

        IRC, freenode, #hurd, 2012-04-20:

            <pinotree> in glibc, we use the generic waitflags.h which, unlike
              linux's version, does not define WEXITED, WNOWAIT, WSTOPPED,
              WCONTINUED
            <pinotree> should the generic bits/waitflags.h define them anyway,
              since they are posix?
            <youpi> well, we'd have to implement them anyway
            <youpi> but otherwise, I'd say yes
            <pinotree> sure, but since glibc headers should expose at least
              everything declared by posix, i thought they should be defined
              anyway
            <youpi> that might bring bugs
            <youpi> some applications might be #ifdefing them
            <youpi> and break when they are defined but not working
            <pinotree> i guess they would define them to 0, andd having them to
              non-zero values shouldn't break them (since those values don't do
              anything, so they would act as if they were 0.. or not?)
            <youpi> no, I mean they would do something else, not define them to
              0
            <pinotree> like posix/tst-waitid.c, you mean?
            <youpi> yes

        See `posix/tst-waitid.out` failure below.

      * `getconf` things (see below the results of `tst-getconf.out`)

      * `getsockopt`, `setsockopt`

        IRC, freenode, #hurd, 2013-02-14

            <gnu_srs> Hi, {get,set}sockopt is not supported on Hurd. This shows
              e.g. in the gnulib's test-{poll,select} code.
            <gnu_srs> Reading
              http://hea-www.harvard.edu/~fine/Tech/addrinuse.html there might
              be reasons _not_ to implement them, comments?
            <pinotree> uh? they are supported on hurd
            <gnu_srs> not  SO_REUSEPORT for setsockopt()
            <pinotree> that isn't the same as claiming "get/setsockopt is not
              supported on hurd"
            <pinotree> most probably that option is not implemented by the
              socket family you are using
            <gnu_srs> OK, some options like  SO_REUSEPORT then, more info in
              the link.
            <pinotree> note also SO_REUSEPORT is not posix
            <pinotree> and i don't see SO_REUSEPORT mentioned in the page you
              linked
            <gnu_srs> No, but SO_REUSEADDR

        IRC, freenode, #hurd, 2013-02-23

            <gnu_srs> as an example, the poll test code from gnulib fails due
              to that problem (and I've told you before)
            <pinotree> gnu_srs: what's the actual failure?
            <pinotree> can you provide a minimal test case showing the issue?
            <gnu_srs> pinotree: A smaller test program:
              http://paste.debian.net/237495/
            <pinotree> gnu_srs: setting SO_REUSEADDR before binding the socket
              works...
            <pinotree> and it seems it was a bug in the gnulib tests, see
              http://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commit;h=6ed6dffbe79bcf95e2ed5593eee94ab32fcde3f4
            <gnu_srs> pinotree: You are right, still the code I pasted pass on
              Linux, not on Hurd.
            <pinotree> so?
            <pinotree> the code is wrong
            <pinotree> you cannot change what bind does after you have called
              it
            * pinotree → out
            <gnu_srs> so linux is buggy?
            <braunr> no, linux is more permissive
            <braunr> (at least, on this matter)

    For specific packages:

      * [[octave]]

  * Create `t/cleanup_kernel-features.h`.

  * Add tests from Linux kernel commit messages for `t/dup3` et al.

  * In `sysdeps/unix/sysv/linux/Makefile`, there are a bunch of
    `-DHAVE_SENDFILE` -- but we do have `sendfile`, too.

    Define `__ASSUME_SENDFILE` to 1 in `kernel-features.h`, if `sendfile`
    works.

  * `/usr/include/pthread.h` overwrite issue

    `make`, after editing `nss/nss_db/db-initgroups.c`:

        [...]
        make[2]: Leaving directory `/media/erich/home/thomas/tmp/glibc/tschwinge/Roger_Whittaker/resolv'
        make  subdir=nss -C nss ..=../ others
        make[2]: Entering directory `/media/erich/home/thomas/tmp/glibc/tschwinge/Roger_Whittaker/nss'
        /usr/bin/install -c -m 644 ../include/pthread.h /usr/include/pthread.h
        /usr/bin/install: cannot remove `/usr/include/pthread.h': Permission denied
        make[2]: *** [/usr/include/pthread.h] Error 1
        make[2]: Leaving directory `/media/erich/home/thomas/tmp/glibc/tschwinge/Roger_Whittaker/nss'
        make[1]: *** [nss/others] Error 2
        make[1]: Leaving directory `/media/erich/home/thomas/tmp/glibc/tschwinge/Roger_Whittaker'
        make: *** [all] Error 2

    See [[!message-id "871uv99c59.fsf@kepler.schwinge.homeip.net"]].  Passing
    `install_root=/INVALID` to `make`/`make check` is a cheap cure.  For `make
    install`, prepending an additional slash to `install_root` (that is,
    `install_root=//[...]`) is enough to obfuscate the Makefile rules.

  * `sysdeps/unix/sysv/linux/syslog.c`

  * `fsync` on a pipe

    IRC, freenode, #hurd, 2012-08-21:

        <braunr> pinotree: i think gnu_srs spotted a conformance problem in
          glibc
        <pinotree> (only one?)
        <braunr> pinotree: namely, fsync on a pipe (which is actually a
          socketpair) doesn't return EINVAL when the "operation not supported"
          error is returned as a "bad request message ID"
        <braunr> pinotree: what do you think of this case ?
        <pinotree> i'm far from an expert on such stuff, but seems a proper E*
          should be returned
        <braunr> (there also is a problem in clisp falling in an infinite loop
          when trying to handle this, since it uses fsync inside the error
          handling code, eww, but we don't care :p)
        <braunr> basically, here is what clisp does
        <braunr> if fsync fails, and the error isn't EINVAL, let's report the
          error
        <braunr> and reporting the error in turn writes something on the
          output/error stream, which in turn calls fsync again
        <pinotree> smart
        <braunr> after the stack is exhausted, clisp happily crashes
        <braunr> gnu_srs: i'll alter the clisp code a bit so it knows about our
          mig specific error
        <braunr> if that's the problem (which i strongly suspect), the solution
          will be to add an error conversion for fsync so that it returns
          EINVAL
        <braunr> if pinotree is willing to do that, he'll be the only one
          suffering from the dangers of sending stuff to the glibc maintainers
          :p
        <pinotree> that shouldn't be an issue i think, there are other glibc
          hurd implementations that do such checks
        <gnu_srs> does fsync return EINVAL for other OSes?
        <braunr>        EROFS, EINVAL
        <braunr>               fd is bound to a special file which does not
          support synchronization.
        <braunr> obviously, pipes and sockets don't
        <pinotree>
          http://pubs.opengroup.org/onlinepubs/9699919799/functions/fsync.html
        <braunr> so yes, other OSes do just that
        <pinotree> now that you speak about it, it could be the failure that
          the gnulib fsync+fdatasync testcase have when being run with `make
          check` (although not when running as ./test-foo)
        <braunr> hm we may not need change glibc
        <braunr> clisp has a part where it defines a macro IS_EINVAL which is
          system specific
        <braunr> (but we should change it in glibc for conformance anyway)
        <braunr> #elif defined(UNIX_DARWIN) || defined(UNIX_FREEBSD) ||
          defined(UNIX_NETBSD) || defined(UNIX_OPENBSD) #define IS_EINVAL_EXTRA
          ((errno==EOPNOTSUPP)||(errno==ENOTSUP)||(errno==ENODEV))
        <pinotree> i'd rather add nothing to clisp
        <braunr> let's see what posix says
        <braunr> EINVAL
        <braunr> so right, we should simply convert it in glibc
        <gnu_srs> man fsync mentions EINVAL
        <braunr> man pages aren't posix, even if they are usually close
        <gnu_srs> aha
        <pinotree> i think checking for MIG_BAD_ID and EOPNOTSUPP (like other
          parts do) will b enough
        <pinotree> *be
        <braunr> gnu_srs: there, it finished correctly even when piped
        <gnu_srs> I saw that, congrats!
        <braunr> clisp is quite tricky to debug
        <braunr> i never had to deal with a program that installs break points
          and handles segfaults itself in order to implement growing stacks :p
        <braunr> i suppose most interpreters do that
        <gnu_srs> So the permanent change will be in glibc, not clisp?
        <braunr> yes

    IRC, freenode, #hurd, 2012-08-24:

        <gnu_srs1> pinotree: The changes needed for fsync.c is at
          http://paste.debian.net/185379/ if you want to try it out (confirmed
          with rbraun)
        <youpi> I agree with the patch, posix indeed documents einval as the
          "proper"  error value
        <pinotree> there's fdatasync too
        <pinotree> other places use MIG_BAD_ID instead of EMIG_BAD_ID
        <braunr> pinotree: i assume that if you're telling us, it's because
          they have different values
        <pinotree> braunr: tbh i never seen the E version, and everywhere in
          glibc the non-E version is used
        <gnu_srs1> in sysdeps/mach/hurd/bits/errno.h only the E version is
          defined
        <pinotree> look in gnumach/include/mach/mig_errors.h
        <pinotree> (as the comment in errno.h say)
        <gnu_srs1> mig_errors.h yes. Which comment: from errors.h: /* Errors
          from <mach/mig_errors.h>.  */ and then the EMIG_ stuff?
        <gnu_srs1> Which one is used when building libc?
        <gnu_srs1> Answer: At least in fsync.c errno.h is used: #include
          <errno.h>
        <gnu_srs1> Yes, fdatasync.c should be patched too.
        <gnu_srs1> pinotree: You are right: EMIG_ or MIG_ is confusing. 
        <gnu_srs1> /usr/include/i386-gnu/bits/errno.h:     /* Errors from
          <mach/mig_errors.h>.  */
        <gnu_srs1> /usr/include/hurd.h:#include <mach/mig_errors.h>

    IRC, freenode, #hurd, 2012-09-02:

        <antrik> braunr: regarding fsync(), I agree that EOPNOTSUPP probably
          should be translated to EINVAL, if that's what POSIX says. it does
          *not* sound right to translate MIG_BAD_ID though. the server should
          explicitly return EOPNOTSUPP, and that's what the default trivfs stub
          does. if you actually do see MIG_BAD_ID, there must be some other
          bug...
        <braunr> antrik: right, pflocal doesn't call the trivfs stub for socket
          objects
        <braunr> trivfs_demuxer is only called by the pflocal node demuxer, for
          socket objects it's another call, and i don't think it's the right
          thing to call trivfs_demuxer there either
        <pinotree> handling MAG_BAD_ID isn't a bad idea anyway, you never know
          what the underlying server actually implements
        <pinotree> (imho)
        <braunr> for me, a bad id is the same as a not supported operation
        <pinotree> ditto
        <pinotree> from fsync's POV, both the results are the same anyway, ie
          that the server does not support a file_sync operation
        <antrik> no, a bad ID means the server doesn't implement the protocol
          (or not properly at least)
        <antrik> it's usually a bug IMHO
        <antrik> there is a reason we have EOPNOTSUPP for operations that are
          part of a protocol but not implemented by a particular server
        <pinotree> antrik: even if it could be the case, there's no reason to
          make fsync fail anyway
        <antrik> pinotree: I think there is. it indicates a bug, which should
          not be hidden
        <pinotree> well, patches welcome then...
        <antrik> thing is, if sock objects are actually not supposed to
          implement the file interface, glibc shouldn't even *try* to call
          fsync on them
        <pinotree> how?
        <pinotree> i mean, can you check whether the file interface is not
          implemented, without doing a roundtrip^
        <pinotree> ?
        <antrik> well, the sock objects are not files, i.e. they were *not*
          obtained by file_name_lookup(), but rather a specific call. so glibc
          actually *knows* that they are not files.
        <braunr> antrik: this way of thinking means we need an "fd" protocol
        <braunr> so that objects accessed through a file descriptor implement
          all fd calls
        <antrik> now I wonder though whether there are conceivable use cases
          where it would make sense for objects obtained through the socket
          call to optionally implement the file interface...
        <antrik> which could actually make sense, if libc lets through other
          file calls as well (which I guess it does, if the sock ports are
          wrapped in normal fd structures?)
        <braunr> antrik: they are
        <braunr> and i'd personally be in favor of such an fd protocol, even if
          it means implementing stubs for many useless calls
        <braunr> but the way things are now suggest a bad id really means an
          operation is simply not supported
        <antrik> the question in this case is whether we should make the file
          protocol mandatory for anything that can end up in an FD; or whether
          we should keep it optional, and add the MIG_BAD_ID calls to *all* FD
          operations
        <antrik> (there is no reason for fsync to be special in this regard)
        <braunr> yes
        <antrik> braunr: BTW, I'm rather undecided whether the right approach
          is a) requiring an FD interface collection, b) always checking
          MIG_BAD_ID, or perhaps c) think about introducing a mechanism to
          explicitly query supported interfaces...

    IRC, freenode, #hurd, 2012-09-03:

        <braunr> antrik: querying interfaces sounds like an additional penalty
          on performance
        <antrik> braunr: the query usually has to be done only once. in fact it
          could be integrated into the name lookup...
        <braunr> antrik: once for every object
        <braunr> antrik: yes, along with the lookup would be a nice thing

    [[!message-id "1351231423.8019.19.camel@hp.my.own.domain"]].

  * `t/no-hp-timing`

    IRC, freenode, #hurd, 2012-11-16

        <pinotree> tschwinge: wrt the glibc topgit branch t/no-hp-timing,
          couldn't that file be just replaced by #include
          <sysdeps/generic/hp-timing.h>?

  * `flockfile`/`ftrylockfile`/`funlockfile`

    IRC, freenode, #hurd, 2012-11-16

        <pinotree> youpi: uhm, in glibc we use
          stdio-common/f{,try,un}lockfile.c, which do nothing (as opposed to eg
          the nptl versions, which do lock/trylock/unlock); do you know more
          about them?
        <youpi> pinotree: ouch
        <youpi> no, I don't know
        <youpi> well, I do know what they're supposed to do
        <pinotree> i'm trying fillig them, let's see
        <youpi> but not why we don't have them
        <youpi> (except that libpthread is "recent")
        <youpi> yet another reason to build libpthread in glibc, btw
        <youpi> oh, but we do provide lockfile in libpthread, don't we ?
        <youpi> pinotree: yes, and libc has weak variants, so the libpthread
          will take over
        <pinotree> youpi: sure, but that in stuff linking to pthreads
        <pinotree> if you do a simple application doing eg main() { fopen +
          fwrite + fclose }, you get no locking
        <youpi> so?
        <youpi> if you don't have threads, you don't need locks :)
        <pinotree> ... unless there is some indirect recursion
        <youpi> ?
        <pinotree> basically, i was debugging why glibc tests with mtrace() and
          ending with muntrace() would die (while tests without muntrace call
          wouldn't)
        <youpi> well, I still don't see what a lock will bring
        <pinotree> if you look at the muntrace implementation (in
          malloc/mtrace.c), basically fclose can trigger a malloc hook (because
          of the free for the FILE*)
        <youpi> either you have threads, and it's need, or you don't, and it's
          a nop
        <youpi> yes, and ?
        <braunr> does the signal thread count ?
        <youpi> again, in linux, when you don't have threads, the lock is a nop
        <youpi> does the signal thread use IO ?
        <braunr> that's the question :)
        <braunr> i hope not
        <youpi> IIRC the signal thread just manages signals, and doesn't
          execute the handler itself
        <braunr> sure
        <braunr> i was more thinking about debug stuff
        <youpi> can't hurt to add them anyway, but let me still doubt that it'd
          fix muntrace, I don't see why it would, unless you have threads
        <pinotree> that's what i'm going next
        <pinotree> pardon, it seems i got confused a bit
        <pinotree> it'd look like a genuine muntrace bug (muntrace → fclose →
          free hook → lock lock → fprint (since the FILE is still set) → malloc
          → malloc hook → lock lock → spin)
        <pinotree> at least i got some light over the flockfile stuff, thanks
          ;)
        <pinotree> youpi: otoh, __libc_lock_lock (etc) are noop in the base
          implementation, while doing real locks on hurd in any case, and on
          linux only if nptl is loaded, it seems
        <pinotree> that would explain why on linux you get no deadlock
        <youpi> unless using nptl, that is?
        <pinotree> hm no, even with pthread it works
        <pinotree> but hey, at least the affected glibc test now passes
        <pinotree> will maybe try to do investigation on why it works on linux
          tomorrow

    [[!message-id "201211172058.21035.toscano.pino@tiscali.it"]].

    In context of [[libpthread]].

    IRC, freenode, #hurd, 2013-01-21

        <braunr> ah, found something interesting
        <braunr> tschwinge: there seems to be a race on our file descriptors
        <braunr> the content written by one thread seems to be retained
          somewhere and another thread writing data to the file descriptor will
          resend what the first already did
        <braunr> it could be a FILE race instead of fd one though
        <braunr> yes, it's not at the fd level, it's above
        <braunr> so good news, seems like the low level message/signalling code
          isn't faulty here
        <braunr> all right, simple explanation: our IO_lockfile functions are
          no-ops
        <pinotree> braunr: i found that out days ago, and samuel said they were
          okay
        <braunr> well, they're not no-ops in libpthreads
        <braunr> so i suppose they replace the default libc stubs, yes
        <pinotree> so the issue happens in cthreads-using apps?
        <braunr> no
        <braunr> we don't have cthreads apps any more
        <braunr> and aiui, libpthreads provides cthreads compatibility calls to
          libc, so everything is actually using pthreads
        <braunr> more buffer management debugging needed :/
        <pinotree> hm, so how can it be that there's a multithread app with no
          libpthread-provided file locking?
        <braunr> ?
        <braunr> file locking looks fine
        <braunr> hm, the recursive locking might be wrong though
        <braunr> ./sysdeps/mach/hurd/bits/libc-lock.h:#define
          __libc_lock_owner_self() ((void *) __hurd_threadvar_location (0))
        <braunr> nop, looks fine too
        <braunr> indeed, without stream buffering, the problem seems to go away
        <braunr> pinotree: it really looks like the stub IO_flockfile is used
        <braunr> i'll try to make sure it's the root of the problem
        <pinotree> braunr: you earlier said that there's some race with
          different threads, no?
        <braunr> yes
        <braunr> either a race or an error in the iostream management code
        <braunr> but i highly doubt the latter
        <pinotree> if the stub locks are used, then libpthread is not
          loaded... so which different threads are running?
        <braunr> that's the thing
        <braunr> the libpthread versions should be used
        <pinotree> so the application is linked to pthread?
        <braunr> yes
        <pinotree> i see, that was the detail i was missing earlier
        <braunr> the common code looks fine, but i can see wrong values even
          there
        <braunr> e.g. when vfprintf calls write, the buffer is already wrong
        <braunr> i've made similar tests on linux sid, and it behaves as it
          should
        <pinotree> hm
        <braunr> i even used load to "slow down" my test program so that
          preemption is much more likely to happen
        <pinotree> note we have slightly different behaviour in glibc's libio,
          ie different memory allocation ways (mmap on linux, malloc for us)
        <braunr> the problem gets systematic on the hurd while it never occurs
          on linux
        <braunr> that shouldn't matter either
        <pinotree> ok
        <braunr> but i'll make sure it doesn't anyway
        <braunr> this mach_print system call is proving very handy :)
        <braunr> and also, with load, unbuffered output is always correct too
        <pinotree> braunr: you could try the following hack
          http://paste.debian.net/227106/
        <braunr> what does it do ?
        <pinotree> (yes, ugly as f**k)
        <braunr> does it force libio to use mmap ?
        <braunr> or rather, enable ?
        <pinotree> provides a EXEC_PAGESIZE define in libio, so it makes it use
          mmap (like on linux) instead of malloc

    `t/pagesize`.

        <braunr> yes, the stub is used instead of the libpthreads code
        <braunr> tschwinge: ^
        <braunr> i'll override those to check that it fixes the problem
        <braunr> hm, not that easy actually
        <pinotree> copy their files from libpthreads to sysdeps/mach/hurd
        <pinotree> hm right, in libpthread they are not that split as in glibc
        <braunr> let's check symbol declaration to understand why the stubs
          aren't overriden by ld
        <braunr> _IO_vfprintf correctly calls @plt versions
        <braunr> i don't know enough about dynamic linking to see what causes
          the problem :/
        <braunr> youpi: it seems our stdio functions use the stub IO_flockfile
          functions
        <youpi> really? I thought we were going through cthreads-compat.c
        <braunr> yes really
        <braunr> i don't know why, but that's the origin of the "duplicated"
          messages issue
        <braunr> messages aren't duplicated, there is a race that makes on
          thread reuse the content of the stream buffer
        <braunr> one*
        <youpi> k, quite bad
        <braunr> at least we know where the problem comes from now
        <braunr> youpi: what would be the most likely reason why weak symbols
          in libc wouldn't be overriden by global ones from libpthread ?
        <youpi> being loaded after libc
        <braunr> i tried preloading it
        <braunr> i'll compare with what is done on wheezy
        <youpi> you have the local-dl-dynamic-weak.diff patch, right?
        <braunr> (on squeeze, the _IO_flockfile function in libc seems to do
          real work unlike our noop stub)
        <braunr> it's the debian package, i have all patches provided there
        <braunr> indeed, on linux, libc provides valid IO_flock functions
        <braunr> ./sysdeps/pthread/flockfile.c:strong_alias (__flockfile,
          _IO_flockfile)
        <braunr> that's how ntpl exports it
        <braunr> nptl*
        <pinotree> imho we should restructure libpthread to be more close to
          nptl
        <braunr> i wish i knew what it involves
        <pinotree> file structing for sources and tests, for example
        <braunr> well yes obviously :)
        <braunr> i've just found a patch that does exactly that for linuxthreads
        <pinotree> that = fix the file locking?
        <braunr> in addition to linuxthreads/lockfile.c (which we also
          equivalently provide), there is
          linuxthreads/sysdeps/pthread/flockfile.c
        <braunr> no, restructiring
        <braunr> restructuring*
        <braunr> i still have only a very limited idea of how the glibc sources
          are organized
        <pinotree> the latter is used as source file when compiling flockfile.c
          in stdio-common
        <braunr> shouldn't we provide one too ?
        <pinotree> that would mean it would be compiled as part of libc proper,
          not libpthread
        <braunr> yes
        <braunr> that's what both linuxthreads and nptl seem to do
        <braunr> and the code is strictly the same, i.e. a call to the internal
          _IO_lock_xxx functions
        <youpi> I guess that's for the hot-dlopen case
        <youpi> you need to have locks properly taken at dlopen time
        <braunr> youpi: do you mean adding an flockfile.c file to our sysdeps
          will only solve the problem by side effect ?
        <braunr> and that the real problem is that the libpthread versions
          aren't used ?
        <youpi>  yes
        <braunr> ok
        <braunr> youpi: could it simply be a versioning issue ?
        <youpi> could be
        <braunr> it seems so
        <braunr> i've rebuilt with the flockfile functions versioned to 2.2.6
          (same as in libc) and the cthreads_compat functions are now used
        <braunr> and the problem doesn't occur any more with my test code
        <braunr> :)
        <youpi> could you post a patch?
        <braunr> i need a few info before
        <youpi> it'd be good to check which such functions are hooked
        <braunr> i suppose the version for functions declared in libpthreads
          shouldn't change, right ?
        <youpi> yes
        <braunr> ok
        <youpi> they didn't have a vresion before
        <braunr> shall i commit directly ?
        <youpi> so it should be fine
        <braunr> well, they did
        <braunr> 2.12
        <youpi> yes, but please tell me when it's done
        <braunr> sure
        <youpi> so I can commit that to debian's eglibc
        <youpi> I mean, before we integrated libpthread build into glibc
        <youpi> so they never had any version before 2.12
        <braunr> ok
        <youpi> basically we need to check the symbols which are both in
          libpthread and referenced in libc
        <youpi> to make sure they have the same version in the reference
        <braunr> ok
        <youpi> only weak references need to be checked, others would have
          produced a runtime error
        <braunr> youpi: done
        <braunr> arg, the version i mention in the comment is wrong
        <braunr> i suppose people understand nonetheless
        <youpi> probably, yes
        <braunr> ah, i can now appreciate the headache this bug hunting gave me
          these last days :)

    IRC, freenode, #hurd, 2013-01-22

        <youpi> braunr: commited to debian glibc
        <youpi> btw, it's normal that the program doesn't terminate, right?
        <youpi> (i.e. it's the original bug you were chasing)
        <braunr> youpi: about your earlier question (yesterday) about my test
          code, it's expected to block, which is the problem i was initially
          working on
        <youpi> ok, so all god
        <youpi> +o

  * `t/pagesize`

    IRC, freenode, #hurd, 2012-11-16

        <pinotree> tschwinge: somehow related to your t/pagesize branch: due to
          the fact that EXEC_PAGESIZE is not defined on hurd, libio/libioP.h
          switches the allocation modes from mmap to malloc

    [[!message-id "87mxd9hl2n.fsf@kepler.schwinge.homeip.net"]].

    IRC, freenode, #hurd, 2013-01-21

        <braunr> why is it a hack ?
        <pinotree> because most probably glibc shouldn't rely on EXEC_PAGESIZE
          like that
        <braunr> ah
        <pinotree> there's a mail from roland, replying to thomas about this
          issue, that this use of EXEC_PAGESIZE to enable mmap or not is just
          wrong
        <braunr> ok
        <pinotree> (the above is
          http://thread.gmane.org/87mxd9hl2n.fsf@kepler.schwinge.homeip.net )
        <braunr> thanks
        <pinotree> (just added the reference to that in the wiki)
        <braunr> pinotree: btw, what's wrong with using malloc instead of mmap
          in libio ?
        <pinotree> braunr: i'm still not totally sure, most probably it should
          be slightly slower currently
        <braunr> locking contention ?
        <braunr> pinotree:
          http://www.sourceware.org/ml/libc-alpha/2006-11/msg00061.html
        <braunr> pinotree: it looks to me there is now no valid reason not to
          use malloc
        <braunr> the best argument for mmap is that libio requires zeroed
          memory, but as the OP says, zeroing a page is usually more expensive
          than a small calloc (even on kernel that keep a list of zeroed pages
          for quick allocations, frequent mmaps() often make this list empty)
        <pinotree> braunr: mmap allocations in libio are rounded to the page
          size
        <braunr> well they have to

  * `LD_DEBUG`

    IRC, freenode, #hurd, 2012-11-22

        <pinotree> woot, `LD_DEBUG=libs /bin/ls >/dev/null` prints stuff and
          then sigsegv
        <tschwinge> Yeah, that's known for years...  :-D
        <tschwinge> Probably not too difficult to resolve, though.

  * Verify baseline changes, if we need any follow-up changes:

      * a11ec63713ea3903c482dc907a108be404191a02
      * 7e2b0c8562b35155820f87b5ff02a8b6850344cc
      * 8c0677fe5d91b7269364ca08fa08ed09e4c2d8c9
      * 5a2a1d75043138e696222ced4560de2fb90b8024
      * 5ae958d74180e2572d198bd7872c86f391de6da7
      * 5b08ac571ff8e94fe96511a532f0d20997de5f52
      * 3d04ff3a5d3ce3616837e1d15e03b6e1b360cf26
      * b2ef2c014b9c66995a3eb4f310ae7c5c510279bf
      * 63c4ed22b5048c8701d8806026c23cc95f0df756
      * ac2b484c02b01307ab6bbe5d45ddbf16d64edf8c
      * e35fcef8b739ed24e083ff8a3078ac14e101cf67
      * 6fb8cbcb58a29fff73eb2101b34caa19a7f88eba
      * 8a492a675e566dc1e666df0a86cbf541442cb179
      * 5dbc3b6cc0b759bf4b22d851ccb9cbf3e3cbc6ef
      * c86434ccb576a3ce35b5a74f72b9f03bd45b522a
      * d22e4cc9397ed41534c9422d0b0ffef8c77bfa53
      * 15bac72bac03faeb3b725b1d208c62160f0c3ad7
      * c08fb0d7bba4015078406b28d3906ccc5fda9d5a
      * 10b3bedcb03386cc280113f552479793e4bac35f
      * 754f7da38b0904b4b989d3500cc8dd5be625cf6a
      * 3cdaa6adb113a088fdfb87aa6d7747557eccc58d
      * 962dba7828cf251a9025ccb43bc6effa30379b72
      * 3162f12e58c3a848db883916843b332b9f8c9d39
      * 1c06ba3100847da6bd1f2e011dc24fa8debd9615
      * 84b9230c404aed4fd3a7bb3d045ca367043dde8c
      * 090555538d4347a52807ba9f08cf20ed13206afe
      * 817328eea788c746131cf151b64fd250200da333
      * c3758feebf7c8786231465da664743c6f0ec79cc
      * 1ac7a2c7b448c851eb8976fcc290a906a4075203
      * c21cc9bcb38a87ff638d1099ca871d94a2192b31
      * 6484ba5ef092b62b7d2112c0d976dbd6d1a40fde
      * b8b4863d78bf26b39918fc753b03ed98ef262903
      * b76b818e6fe2061e778b3a9bbe63c554c3f9b3c1
      * 8e9f92e9d5d7737afdacf79b76d98c4c42980508 -- `_dl_map_object` in
        `sysdeps/mach/hurd/dl-sysdep.c`
      * 0e516e0e14f2f9783a21cd1727bc53776341f857
      * a1fb5e3ebe9d38b5ae6c5bfbfaa04882d52355bc
      * cf7c9078a5acdbb435498ace92cd81009637a971
      * db753e2cfb2051ebf20dc089f87c5b1297cc2cff
      * 4a531bb0b3b582cb693de9f76d2d97d970f9a5d5 -- looks good.
      * 5bd6dc5c2c68fe98691db9b40f87d9b68ea9565b
      * 451f001b50870604e1f2daef12f04f9f460d3997 +
        a85b5cb4d4a5fc56e2b38638d270bf2daa67eb6c -- BZ10484.  `nptl/Versions
        [libc] (GLIBC_PRIVATE): Export __libc_alloca_cutoff`.  We don't even
        define it yet.  Also see
        [[glibc___libc_alloca_cutoff_should_be_lowered]].
      * 1086d70d916fd0eb969b3d89ff88abd35f6a5c34
      * cfa28e560ef69372b9e15e9a2d924a0fbcfc7bca
      * 8cf8ce1702c354a8266e3cfa6ab54c2467d1873f
      * 68dc949774cb651d53541df4abdc60327f7e096b
      * 70181fddf1467996bea393d13294ffe76b8a0853
      * a77e8cbc394ab098aa1fc3f0a6645a38348d21ca
      * 32465c3ea007065acd8ca8199f130cdf4068130d
      * 18ba70a559c52719fd94a713cc380514d9d19125
      * 620a05296fe3380b7441ba7720e8b25c48a8c28c
      * [low] e6c61494125126d2ba77e5d99f83887a2ed49783 -- `Fix memory leak in
        TLS of loaded objects.` Do we need to replicate `nptl/allocatestack.c`
        hunk?
      * 6e04cbbe79f5965809fdbf1f28d7ae8b4af74d31 +
        1bfbe0d335d3fc44a492648b974a0db19975f6d8 -- `Fix
        pathconf(_PC_BUF_SIZE).`
      * 28377d1bf58625172a1734b92e835591d4d23a18 -- `Optimize fdopendir a bit.`
      * 7fb90fb89bbdf273ab7ab96517fe1b156cd7aee1 +
        6fb2dde3f1aa3a1419cb6c2dfa53dd1d506722a4 -- `Fix Linux getcwd for long
        paths`
      * f574184a0e4b6ed69a5d9a3234543fba6d2a7367 -- `Fix sched_setscheduler
        call in spawn implementation`
      * 3b85df27870a47ed1db84e948e37a5a50a178a92 +
        f50ef8f1efdd1f2b040acbb8324604f168e8832a -- sysconf
      * 68a3f91fcad464c4737c1eaed4ae0bf539801fb2 -- `Fix reporting of invalid
        timeouts in emulated pselect`
      * ea389b12b3b65c4a7fa91fa76f8c99867eb37865 -- `strndup -> __strndup`;
        strndupa?
      * 7e4afad5bcf49e03c3b987399c6a8f66a9018660 -- `Nicer output for negative
        error numbers in strerror_r`.  Change needed for
        `sysdeps/mach/_strerror.c`?
      * 7ea72f99966a65a56aedba817ee2413ff9b1f23c +
        adcd5c15d2a37794d021104160b425ff61f88219 -- `Always fill output buffer
        in XPG strerror function`.  Change needed for
        `sysdeps/mach/xpg-strerror.c`?
      * a91710475294c66d0005bdaae0919d36ef8ce3d2 -- sotruss ([[debugging]],
        [[profiling]]).  Does it work?
      * b1ebd700c5295a449f8d114740f0d1fb6e6b2eb5 +
        80e2212d8e59933a1641f029ebd360526ff0e074 +
        4997db742946d08be4378cf91221f558f928bc73 -- `Don't document si_code
        used for raise()`.  Also for `bits/siginfo.h`?
      * 11988f8f9656042c3dfd9002ac85dff33173b9bd -- pldd, Does it work?
        Probably not: needs `/proc/[PID]/auxv`, `/proc/[PID]/exe`,
        `/proc/[PID]/mem` ([[!tag open_issue_hurd]],
        [[hurd/translator/procfs]]).
      * 9113ea1f3f29b3aee710efc829e85a9772bcb836 -- `--experimental-malloc`.
        Watch what happens.
      * 4e34ac6a1e256f40ab0d8eeed37aa1ea83440e76 -- `-defsym=_begin=0`.  Watch
        what happens.  Native build: apparently OK.
      * f781ef4015504e8a1da649c266584976238aa079 (`--with-default-link`) +
        1b74661a6b93a892ecb1c717dedeedba5c2a976c +
        fd5e21c75d8e9221d766f4bc922a237265514ec2.  Watch what happens.  Native
        build: `use-default-link = no`.
      * de283087c74f720cf8a7171972e72b5fa2b45e79 (`Handle Lustre filesystem`),
        4e5f31c847982997c856f03bbc35134e9fd0f61f (`Handle ext4 in
        {,f}pathconf`).  What about stuff like that for us?
      * d30cf5bb00bfb286ff14d931fb69f5b53724bcdc (`Find readelf with
        AC_CHECK_TOOL`).  Aren't there more in other configure.in and Makefile
        files?
      * 7a03a9c8c4b37b88ac5e82b557d974f3161ddaf9 (`Add read barriers in
        cancellation initialization`).  Is this needed in other places, too?
      * [low] 5744c68d78f6ca6c6500e2c8d3d85b3a31f4ed2a (`Align x86 TCB to 64
        bytes`).  Probably we have hidden somewhere such a constant, too (in
        libpthread).
      * d96de9634a334af16c0ac711074c15ac1762b23c +
        ecb1482ffd85fd3279642b1dc045aa867ad4d415 (`Try shell in posix_spawn*
        only in compat mode`).  Change looks good, but what about
        `SPAWN_XFLAGS_TRY_SHELL` for us?
      * 3ce1f2959437e952b9db4eaeed2407424f11a4d1 (`Make several tool features
        mandatory and simplify the code.`).  Generally looks good.
          * `locale/global-locale.c`: Apparently, no one is using
            `_HURD_THREADVAR_LOCALE`.  But it is exported via
            `hurd/threadvar.h`.
          * `mach/devstream.c`: reversed.  Fixed in
            `t/repair-mach_devstream.c`.
          * `malloc/arena.c`: should be OK.
      * `Remove support for !USE___THREAD`.
        d063d164335938d557460bebaa7cfe388157b627 (generally looks good;
        `csu/errno-loc.c` (should be OK); `include/errno.h` (fixed)) +
        (de82006d43e198fd162807c9adc720c7ebd728a3 +
        037e9fe21c92216ef7032ea2796781ec27ca182a) +
        995a80dfbcb443ead5aa22682c884ec5c827a2ea (discussing) +
        bc7e1c3667b577ad418f7520df2a7dbccea04ee9 (should be ok).
      * [OK] 22a89187139a9083ca73989bfd11597e0f85cb61 (`malloc: Remove all
        kinds of unused configuration options and dead code.`).  `NO_STARTER`
        changes (should be OK).
      * [high] `pagesize`, 02d46fc4b969e25e4ba0c54aa95fa98d7279bd05 (`Simplify
        malloc initialization`); aebae0537dcb408100b88c6b7647a7e858c43237,
        [[!sourceware_PR 11929]].  Is this all kosher for us?  See
        [[!message-id "87mxd9hl2n.fsf@kepler.schwinge.homeip.net"]].
      * [OK] 83cd14204559abbb52635006832eaf4d2f42514a (`Remove --wth-tls
        option, TLS support is required`).
      * a7c8e6a1478de9f990b11e5e853318ccbe4330f2 (`Fix invalid conversion in
        __cmsg_nxthdr`).  Probably just a C++ thing and not relevant for us;
        see [[!message-id "87r52nk1kx.fsf@kepler.schwinge.homeip.net"]].
      * [low] `mmap`, 110946e473b38fc3896212e416d9d7064fecd5b7.  Kosher with
        respect to our [[glibc/mmap]] peculiarities?
      * [OK] `__attribute__ ((__leaf__))`, `BZ #13344`,
        aa78043a4aafe5db1a1a76d544a833b63b4c5f5c +
        49a43d80ec5c97cf6136b1ee2687414773b2d5aa +
        3871f58f065dac3917eb18220a479e9591769c8c +
        9beb2334930db81ceada5aa6051fe5ac0554db32 +
        0ffc4f3ebaace42cd545db55a2ac50b6e0cc7d89 +
        edc5984d4d18296d7aa3d8f4ed8f7336a743170e +
        57769839788e2c62b68d9dfbf4b35052321278ba.
        <http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>.
      * [low] `conformtest`, 3134156779108fe8b46e0f4cd60d837572faaa93 +
        4efeffc1d583597e4f52985b9747269e47b754e2 +
        d94a4670800de6e8f088b8630ad5142866127980 -- should probably mirror
        `bits/siginfo.h` changes.
      * [low] stack guard, 6c6a98c983c44b440ae66d2aa8f32529a9dd7bfe,
        [[!message-id "4F3BE241.9090409@mentor.com"]] -- anything needed for
        us?
      * [low] `libc-lockP.h` 9463518d0d314d7bd0160315e0ef30e15be08985 --
        probably should do similar changes, also to the generic file.
      * [low] `bits/socket.h`/`bits/socket_type.h` [[!message-id
        "Pine.LNX.4.64.1203090206420.18868@digraph.polyomino.org.uk"]]
        02a6f887cb3e2c048937111eb4cf150d397609de -- probably should do the same
        for the generic version as used by GNU Hurd.
      * [low] CFI for `_start`, 6a1bd2a100c958d30bbfe8c9b8f9071d24b7c3f4,
        [[!message-id "20120316180551.GA6291@host2.jankratochvil.net"]] -- what
        about other architectures?
      * `linkobj/libc.so`, 510bbf14b4f25fec8ee3a2d24de3f24bdbf84333 -- need to
        adapt for (conditional?) Sun RPC reversion (if that was the original
        cause for the patch)?
      * [low] `Add __fsword_t and use it in bits/statfs.h`,
        3e5aef87d76cfa7354f2b0d82b96e59280720796, [[!message-id
        "20120517134700.GA19046@intel.com"]] -- only updates one copy of
        `bits/statfs.h`; update the others, too, for consistency.
      * [low] 789bd351b45f024b7f51e4886bf46b8e887ab6da: remove
        `libc_hidden_def` in `sysdeps/mach/hurd/accept4.c`?
      * 0948c3af9dfb3bc1312d6bed2f3a6bfd4e96eef4,
        b80af2f40631871cf53a5e39d08d5d5516473b96,
        04570aaa8ad88caad303f8afe469beb4cf851e17 `_dl_initial_dtv`: OK?
      * [very low] ea4d37b3169908615b7c17c9c506c6a6c16b3a26 `Implement
        POSIX-generic sleep via nanosleep rather than SIGARLM.`: any benefit
        using that one (with `sysdeps/mach/nanosleep.c`) instead of
        `sysdeps/mach/sleep.c`?
      * *baseline*
      * ea4d37b3169908615b7c17c9c506c6a6c16b3a26 -- IRC, freenode, #hurd,
        2012-11-20, pinotree: »tschwinge: i agree on your comments on
        ea4d37b3169908615b7c17c9c506c6a6c16b3a26, especially since mach's
        sleep.c is buggy (not considers interruption, extra time() (= RPC)
        call)«.


## Update

`baseline`, `t/regenerate_configure` (could now be removed),
`t/master_backports`, `t/eglibc_backports`, `t/host-independency`,
`tschwinge/Roger_Whittaker`


# Build

Here's a log of a glibc build run; this is from our [[Git repository's
60f4d2f33666d77ac018cb9956675dcad04bb996 (2013-02-12;
fbeafedeea37e0af1984a6511018d159f5ceed6a (2012-11-03))
sources|source_repositories/glibc]], run on coulomb.SCHWINGE.

    $ export LC_ALL=C
    $ ../Roger_Whittaker/configure AUTOCONF=: --prefix=/usr --disable-profile --disable-multi-arch --build=i486-gnu --host=i486-gnu CC=gcc-4.7 CXX=g++-4.7 2>&1 | tee log_build
    [...]
    $ make install_root=/INVALID 2>&1 | tee log_build_
    [...]

This takes up around 550 MiB, and needs roughly X min on kepler.SCHWINGE and
100 min on coulomb.SCHWINGE.

<!--

    $ (make install_root=/INVALID && touch .go-install) 2>&1 | tee log_build_ && test -f .go-install && (make install_root="$PWD".install install && touch .go-test) 2>&1 | tee log_install && test -f .go-test && ln -s /usr/lib/i386-*gnu/libstdc++.so.6 /lib/i386-*gnu/libgcc_s.so.1 mach/libmachuser.so.1 hurd/libhurduser.so.0.3 ./ && make -k install_root=/INVALID check fast-check=yes 2>&1 | tee log_test

-->


## Analysis

    $ toolchain/logs/process glibc build fetch coulomb.SCHWINGE

TODO.

  * With GCC >= 4.5, there's a ton of these warnings:

        hurd/hurd.h: In function '__hurd_fail':
        hurd/hurd.h:73: warning: case value '0' not in enumerated type 'error_t'

    ... as well as a few individual instances:

        hurdselect.c: In function '_hurd_select':
        hurdselect.c:265: warning: case value '0' not in enumerated type 'error_t'
        get-host.c: In function '_hurd_get_host_config':
        get-host.c:38: warning: case value '0' not in enumerated type 'error_t'
        hurdmsg.c: In function '_S_msg_get_init_ints':
        hurdmsg.c:186: warning: case value '0' not in enumerated type 'error_t'
        hurdmsg.c: In function '_S_msg_set_init_ints':
        hurdmsg.c:273: warning: case value '0' not in enumerated type 'error_t'
        intr-msg.c: In function '_hurd_intr_rpc_mach_msg':
        intr-msg.c:363: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/setitimer.c: In function 'timer_thread':
        sysdeps/mach/hurd/setitimer.c:117: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/wait4.c: In function '__wait4':
        sysdeps/mach/hurd/wait4.c:40: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/fork.c: In function '__fork':
        sysdeps/mach/hurd/fork.c:423: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/spawni.c: In function '__spawni':
        sysdeps/mach/hurd/spawni.c:600: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/setpriority.c: In function 'setonepriority':
        sysdeps/mach/hurd/setpriority.c:66: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/ioctl.c: In function 'send_rpc':
        sysdeps/mach/hurd/ioctl.c:177: warning: case value '0' not in enumerated type 'error_t'
        sysdeps/mach/hurd/ioctl.c: In function '__ioctl':
        sysdeps/mach/hurd/ioctl.c:306: warning: case value '0' not in enumerated type 'error_t'

    [[!message-id "20120723195143.7F8142C0B9@topped-with-meat.com"]].

  * baseline
    fd5bdc0924e0cfd1688b632068c1b26f3b0c88da..2ba92745c36eb3c3f3af0ce1b0aebd255c63a13b
    (or probably Samuel's mmap backport) introduces:

        ../sysdeps/mach/hurd/mmap.c: In function '__mmap':
        ../sysdeps/mach/hurd/mmap.c:54:15: warning: comparison between pointer and integer [enabled by default]
        ../sysdeps/mach/hurd/mmap.c:66:21: warning: comparison between pointer and integer [enabled by default]
        ../sysdeps/mach/hurd/mmap.c:143:13: warning: comparison between pointer and integer [enabled by default]
        ../sysdeps/mach/hurd/mmap.c:165:24: warning: comparison between pointer and integer [enabled by default]

  * baseline
    fd5bdc0924e0cfd1688b632068c1b26f3b0c88da..2ba92745c36eb3c3f3af0ce1b0aebd255c63a13b
    introduces:

        nscd_gethst_r.c: In function '__nscd_get_nl_timestamp':
        nscd_gethst_r.c:112:4: warning: implicit declaration of function 'time' [-Wimplicit-function-declaration]

    This was already present before:

        nscd_gethst_r.c: In function 'nscd_gethst_r':
        nscd_gethst_r.c:426:5: warning: implicit declaration of function '__close' [-Wimplicit-function-declaration]

  * baseline
    2ba92745c36eb3c3f3af0ce1b0aebd255c63a13b..7a270350a9bc3110cd5ba12bbd8c5c8c365e0032
    introduces:

        tst-relsort1.c:6:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]

  * baseline
    fc56c5bbc1a0d56b9b49171dd377c73c268ebcfd..cbc818d0ee66065f3942beffdca82986615aa19a
    introduces

        +gcc-4.6 tst-printf-round.c -c -std=gnu99 -fgnu89-inline  -O2 -Wall -Winline -Wwrite-strings -fmerge-all-constants -frounding-math -g -Wno-parentheses -Wstrict-prototypes         -I../include -I[...]/tschwinge/Roger_Whittaker.build-gcc-4.
        +tst-printf-round.c: In function 'do_test':
        +tst-printf-round.c:203:11: warning: passing argument 3 of 'test_hex_in_one_mode' discards 'const' qualifier from pointer target type [enabled by default]
        +tst-printf-round.c:139:1: note: expected 'const char **' but argument is of type 'const char * const*'
        +tst-printf-round.c:208:8: warning: passing argument 3 of 'test_hex_in_one_mode' discards 'const' qualifier from pointer target type [enabled by default]
        +tst-printf-round.c:139:1: note: expected 'const char **' but argument is of type 'const char * const*'
        +tst-printf-round.c:216:8: warning: passing argument 3 of 'test_hex_in_one_mode' discards 'const' qualifier from pointer target type [enabled by default]
        +tst-printf-round.c:139:1: note: expected 'const char **' but argument is of type 'const char * const*'
        +tst-printf-round.c:224:8: warning: passing argument 3 of 'test_hex_in_one_mode' discards 'const' qualifier from pointer target type [enabled by default]
        +tst-printf-round.c:139:1: note: expected 'const char **' but argument is of type 'const char * const*'

         gcc-4.6 test-wcschr.c -c -std=gnu99 -fgnu89-inline  -O2 -Wall -Winline -Wwrite-strings -fmerge-all-constants -frounding-math -g -Wno-parentheses -Wstrict-prototypes         -I../include -I[...]/tschwinge/Roger_Whittaker.build-gcc-4.6-486
        +In file included from test-wcschr.c:2:0:
        +../string/test-strchr.c: In function 'check1':
        +../string/test-strchr.c:249:3: warning: passing argument 1 of 'stupid_STRCHR' from incompatible pointer type [enabled by default]
        +../string/test-strchr.c:77:1: note: expected 'const wchar_t *' but argument is of type 'char *'
        +../string/test-strchr.c:249:22: warning: initialization from incompatible pointer type [enabled by default]
        +../string/test-strchr.c:252:5: warning: passing argument 2 of 'check_result' from incompatible pointer type [enabled by default]
        +../string/test-strchr.c:92:1: note: expected 'const wchar_t *' but argument is of type 'char *'
        +../string/test-strchr.c:252:5: warning: passing argument 4 of 'check_result' from incompatible pointer type [enabled by default]
        +../string/test-strchr.c:92:1: note: expected 'const wchar_t *' but argument is of type 'char *'


# Install

TODO.

    $ make install_root="$PWD".install install 2>&1 | tee log_install
    [...]

This takes up around 100 MiB, and needs roughly X min on kepler.SCHWINGE and 16
min on coulomb.SCHWINGE.


## Analysis

    $ toolchain/logs/process glibc install fetch coulomb.SCHWINGE

TODO.


# Testsuite

    $ make -k install_root=/INVALID check fast-check=yes 2>&1 | tee log_test
    [...]

This needs roughly X min on kepler.SCHWINGE and 60 min on coulomb.SCHWINGE.

Specifying `fast-check=yes` disables the `conformtest` which takes 1.75 h (out
of 2.75 h total) on coulomb.SCHWINGE, doesn't pass anyway, and clearly isn't
our most critical issue to solve.


## Analysis

    $ toolchain/logs/process glibc test fetch coulomb.SCHWINGE

Failures, mostly in order of appearance:

  * `check-abi`, `check-abi-libmachuser`, `check-abi-libhurduser`,
    `check-abi-libBrokenLocale`, `check-abi-libm`, `check-abi-libdl`,
    `check-abi-libcrypt`, `check-abi-libresolv`, `check-abi-librt`,
    `check-abi-libnsl`, `check-abi-libutil`, `check-abi-libc`, `check-abi-ld`,
    `c++-types.data`

    Reference files are missing.

  * `math/test-float.out`, `math/test-double.out`

    A handful of ULP failures.

  * `math/test-ldouble`, `math/test-ildoubl`, `math/test-ifloat`,
    `math/test-idouble`

    SIGSEGV.  Or SIGILL.

  * `stdlib/bug-getcontext.out`

        getcontext failed, errno: 1073741902.

    Is not implemented; see above.  In 8958805c11c741d9211e20612c86271d906c9a0b
    testing, `stdlib/bug-getcontext.out` now says: *Skipping test; no support
    for FP exceptions.*, in cba1c83ad62a11347684a9daf349e659237a1741 testing,
    it's back to the previous failure.

  * `stdlib/tst-secure-getenv.out`

        open (/proc/self/exe): No such file or directory

    Needs [[`/proc/self/exe`|hurd/translator/procfs/jkoenig/discussion]].

  * `stdlib/tst-strtod-round.out`

        strtold (-0x0.7p-16445) returned -0x0.0000000000008p-16385 not -0x0.000000000000001p-16385 (FE_DOWNWARD)
        strtold (-0x0.7p-16494) returned -0x0.0000000000008p-16385 not -0x0.000000000000001p-16385 (FE_DOWNWARD)

  * `stdio-common/bug22.out`

        Timed out: killed the child process

    Known problem.

  * `libio/tst-atime.out`, `dirent/tst-fdopendir.out`

    `libio/tst-atime.out`:

        atime has not changed

    Due to `ext2fs --no-atime`.

    `dirent/tst-fdopendir.out`:

        directory atime changed

    Due to `ext2fs --atime` (default).

  * `libio/tst-fopenloc.check`, `posix/bug-regex31-mem`,
    `posix/tst-fnmatch-mem`, `misc/tst-error1-mem`

        Memory not freed:
        -----------------
           Address     Size     Caller
        0x0807e268   0x8000  at 0x10c71c4

    Caused by different memory allocation way in libio, see
    [[!message-id "87mxd9hl2n.fsf@kepler.schwinge.homeip.net"]]

  * `dlfcn/bug-atexit3.out`

    Originally:

        dlopen failed: libstdc++.so.6: cannot open shared object file: No such file or directory

    See [[!message-id "20090420002344.11798.qmail@s461.sureserver.com"]].
    Hacked around with `ln -s /usr/lib/i386-*gnu/libstdc++.so.6
    /lib/i386-*gnu/libpthread-stubs.so.0 /lib/i386-*gnu/libgcc_s.so.1 ./`.
    This is a bug in the glibc test harness.  Should probably use some
    `configure` magic akin to the `fixincludes` stuff (`gcc-4.4
    -print-file-name=libstdc++.so.6`, etc.).

    Even if that that is being worked around, the tests nowadays
    ([[packaging_libpthread]]) fail with:

        dlopen failed: [...]/libc.so.0.3: version `GLIBC_2.13_DEBIAN_31' not found (required by [...]/libstdc++.so.6)

  * `dlfcn/tststatic.out`, `dlfcn/tststatic2.out`

    SIGSEGV.

    `LD_LIBRARY_PATH` doesn't contain the `mach` and `hurd` directories; yet
    the test shouldn't just SIGSEGV.

  * `dirent/opendir-tst1.out`, `dirent/tst-fdopendir2.out`

    `dirent/opendir-tst1.out`:

        `opendir' succeeded on a FIFO???

    `dirent/tst-fdopendir2.out`:

        fdopendir with normal file descriptor did not fail

    `opendir` and `fdopendir` do not return `ENOTDIR` if `fd` is not a
    directory.

  * `posix/tst-waitid.out`

    Intermittent.

        SIGCHLD for stopped status 0
        SIGCHLD for stopped pid -1
        SIGCHLD for killed code 1
        SIGCHLD for killed status 0
        SIGCHLD for killed pid -1

  * `posix/bug-glob2.out`

        Timed out: killed the child process

  * `posix/annexc.out`

    Failure ignored by the glibc testsuite.

  * `posix/tst-getconf.out`

    Ends with:

        getconf POSIX_ALLOC_SIZE_MIN /: [...]/posix/getconf: pathconf: /: Invalid argument

    It fails because of unimplemented pathconf cases: `_PC_ALLOC_SIZE_MIN`,
    `_PC_REC_INCR_XFER_SIZE`, `_PC_REC_MAX_XFER_SIZE`, `_PC_REC_MIN_XFER_SIZE`,
    `_PC_REC_XFER_ALIGN`, `_PC_SYMLINK_MAX`, `_PC_2_SYMLINKS`.

    `_CS_GNU_LIBPTHREAD_VERSION` is provided by libpthread when compiled as
    add-on.

  * `posix/tst-vfork3-mem`

        + 0x0804cee0 Alloc 10 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 11 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 12 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 17 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 18 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 19 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 20 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 25 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 26 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 27 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 28 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 33 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 34 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 35 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 36 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 41 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 42 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 43 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 44 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 49 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 50 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 51 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 52 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 57 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 58 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 59 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 60 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 65 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 66 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 67 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 68 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 73 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 74 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 75 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        + 0x0804cfa8 Alloc 76 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x00000008 Alloc 81 duplicate: 0x10df0c8 $BUILDDIR/libc.so.0.3:(argz_create+0x68)[0x10df0c8]
        + 0x0804cee0 Alloc 82 duplicate: 0x1095389 $BUILDDIR/libc.so.0.3:[0x1095389]
        + 0x0804cf90 Alloc 83 duplicate: 0x1156963 $BUILDDIR/libc.so.0.3:(tsearch+0xe3)[0x1156963]
        - 0x0804c8d8 Free 84 was never alloc'd 0x10955fc
        - 0x0804c960 Free 87 was never alloc'd 0x115672f
        - 0x0804c9b8 Free 88 was never alloc'd 0x1156737
        
        Memory not freed:
        -----------------
           Address     Size     Caller
        0x0804cfa8     0x73  at 0x10df0c8
        0x00000008        0  at 0x10df0c8

    Perhps because we implement `vfork` in terms of `fork` (`posix/vfork.c`)?

  * `io/test-lfs.out`

        /home/thomas/tmp/glibc/tschwinge/Roger_Whittaker.build/io/test-lfs: cannot write test string to large file: Invalid argument

  * `io/tst-futimesat.out`

        file created
        futimesat failed

    `futimesat` is a stub.

  * `resource/bug-ulimit1.out`

        Result of ulimit (UL_SETFSIZE, 10000): 0
        Result of ulimit(UL_GETFSIZE): 10000

    Buggy sysdeps/unix/bsd/ulimit.c return values.

    [[!message-id "201211182342.51619.toscano.pino@tiscali.it"]]

    Fixed in glibc >= 2.18.

  * `misc/tst-pselect.o`

        tst-pselect.c: In function 'do_test':
        tst-pselect.c:33:17: error: 'SA_NOCLDWAIT' undeclared (first use in this function)

  * `gmon/tst-sprofil.out`

        Floating point exception

  * `nss//libnss_test1.so`

        [...]/nss/nss_test1.os: In function `_nss_test1_getpwent_r':
        [...]/nss/nss_test1.c:60: undefined reference to `pthread_mutex_lock'
        [...]/nss/nss_test1.c:85: undefined reference to `pthread_mutex_unlock'

  * `rt/tst-timer.out`

    No message.

  * `rt/tst-timer2.o`

        tst-timer2.c: In function 'do_test':
        tst-timer2.c:33:23: error: 'SIGRTMIN' undeclared (first use in this function)

  * `rt/tst-aio2`, `rt/tst-aio3`, `rt/tst-aio9`, `rt/tst-aio10`,
    `rt/tst-mqueue3`, `rt/tst-mqueue5.o`, `rt/tst-mqueue6`, `rt/tst-mqueue8`,
    `rt/tst-timer3`, `rt/tst-timer4.o`, `rt/tst-timer5.o`,
    `rt/tst-cputimer1.o`, `rt/tst-cputimer2.o`, `rt/tst-cputimer3.o`,
    `elf/tst-thrlock`

        [...]/rt/tst-aio2.o: In function `do_test':
        [...]/rt/tst-aio2.c:62: undefined reference to `pthread_barrier_init'
        [...]/rt/tst-aio2.c:94: undefined reference to `pthread_barrier_wait'
        [...]/rt/tst-aio2.o: In function `thrfct':
        [...]/rt/tst-aio2.c:35: undefined reference to `pthread_barrier_wait'

        tst-mqueue5.c: In function 'rtmin_handler':
        tst-mqueue5.c:50:14: error: 'SIGRTMIN' undeclared (first use in this function)

        [...]/rt/tst-mqueue6.o: In function `do_test':
        [...]/rt/tst-mqueue6.c:127: undefined reference to `pthread_attr_init'
        [...]/rt/tst-mqueue6.c:149: undefined reference to `pthread_attr_setguardsize'
        [...]/rt/tst-mqueue6.c:211: undefined reference to `pthread_attr_setguardsize'
        [...]/rt/tst-mqueue6.c:262: undefined reference to `pthread_attr_destroy'
        [...]/rt/tst-mqueue6.c:128: undefined reference to `pthread_attr_setguardsize'
        [...]/rt/tst-mqueue6.o: In function `fct':
        [...]/rt/tst-mqueue6.c:79: undefined reference to `pthread_self'
        [...]/rt/tst-mqueue6.c:79: undefined reference to `pthread_getattr_np'
        [...]/rt/tst-mqueue6.c:88: undefined reference to `pthread_attr_getguardsize'
        [...]/rt/tst-mqueue6.c:95: undefined reference to `pthread_attr_destroy'
        [...]/rt/tst-mqueue6.c:95: undefined reference to `pthread_attr_destroy'

        [...]/elf/tst-thrlock.o: In function `do_test':
        [...]/elf/tst-thrlock.c:38: undefined reference to `pthread_create'
        [...]/elf/tst-thrlock.c:48: undefined reference to `pthread_join'

  * `rt/tst-aio8.out`

        r = -1, e = 1073741902 (Function not implemented)

    Should work with [[!message-id
    "201209302353.51055.toscano.pino@tiscali.it"]] in libpthread.

  * `debug/tst-chk1.out`

    Intermittent.  Timeout.  Unknown.

  * `debug/tst-chk2.out`, `debug/tst-chk3.out`, `debug/tst-lfschk2.out`,
    `debug/tst-lfschk3.out`

    Unknown.

  * `debug/tst-chk4.out`, `debug/tst-chk5.out`, `debug/tst-chk6.out`,
    `debug/tst-lfschk4.out`, `debug/tst-lfschk5.out`, `debug/tst-lfschk6.out`

        [...]/debug/tst-chk4: [...]/libc.so.0.3: version `GLIBC_2.13_DEBIAN_31' not found (required by [...]/libstdc++.so.6)
        [...]/debug/tst-chk4: [...]/libc.so.0.3: version `GLIBC_2.13_DEBIAN_31' not found (required by [...]/libgcc_s.so.1)

  * `debug/tst-longjmp_chk2.out`

    SIGSEGV.

        not on alternate stack
         in signal handler
         on alternate stack
         out of signal handler
         on alternate stack

    It says *alternate stack*.

  * `inet/tst-ether_line.o`

        tst-ether_line.c: In function 'do_test':
        tst-ether_line.c:19:19: error: 'ETH_ALEN' undeclared (first use in this function)

    Will either need a `hurd/netinet/if_ether.h` that includes
    `<net/if_ether.h>`, or can do that in the generic `netinet/if_ether.h`?
    See also [[!sourceware_PR 11142]].

  * `login/tst-grantpt.out`

        posix_openpt(O_RDWR) failed
        errno 1073741902 (Function not implemented)

    `posix_openpt` is a stub.

        grantpt(): expected: return = -1, errno = 1073741846
                   got: return = -1, errno = -303

    `grantpt` (actually `ptsname_r`), does not fail with `ENOTTY` when the `fd`
    does not refer to a PTY master.

  * `elf/tst-stackguard1-static.out`, `elf/tst-stackguard1.out`

        differences 0 defaults 0
        stack guard canaries are not randomized enough
        nor equal to the default canary value

    Sometimes times out.

  * `elf/tst-tls9-static.out`

    SIGSEGV.

  * `elf/tst-dlmopen1.out`

    SIGSEGV.

  * `elf/tst-audit1.out`, `elf/tst-audit2.out`

    SIGKILL.

  * `elf/check-textrel.out`

        $BUILDDIR/libc.so.dyn: *** text relocations used

  * `elf/check-execstack.out`

        $BUILDDIR/libc.so.phdr: *** executable stack signaled

  * `elf/check-localplt.out`

    Around 500 or so `Extra PLT reference`.

  * `check-local-headers.out`

    A lot.  Including `/usr/include/device/*.h`, `/usr/include/mach/*.h`,
    `/usr/include/hurd/*.h`.

Earlier failures; no longer seen:

  * `test-assert-perr.out`

    Fails intermittently.  Unknown.

  * `test-multiarch.out`

    Needs [[`/proc/cpuinfo`|hurd/translator/procfs/jkoenig/discussion]]
    providing the `flags` line.

  * `elf/tst-array*`

    No longer fail with GCC 4.7.
    [[!message-id "50950082.1070906@df1tl.local.here"]].

  * `io/ftwtest`, `posix/globtest`, `iconvdata/iconv-test`, `intl/tst-gettext`,
    `malloc/tst-mtrace`, `elf/tst-pathopt`, `iconvdata/tst-tables`,
    `grp/tst_fgetgrent`,
    `posix/wordexp-tst`, `localedata/bug-setlocale1.out`, `posix/tst-getconf`

        /home/thomas/tmp/glibc/tschwinge/Roger_Whittaker.build-gcc-4.4-486.O/io/ftwtest: error while loading shared libraries: libmachuser.so.1: cannot open shared object file: No such file or directory

    Looking into `localedata/bug-setlocale1.c`, it is clear what it going on:
    only the root of the build directory is added for `--library-path`, but
    none of the other directories that are additionally used.  This is a bug in
    the glibc test harness.  Hacked around by `ln -s mach/libmachuser.so.1
    hurd/libhurduser.so.0.3 ./`.  Hopefully the other instances are similar.

  * `assert/test-assert.out`

    Fails sometimes...

  * `math/test-fenv.out`

    Used to fail (is listed in Debian eglibc-2.13-21's
    `expected-results-i486-gnu-libc`), but something between
    22bcba37dd3b782b1a1ec7bf51da468e48f4d2eb and
    005b7594ffe209639dd1ef2b9ed9a4c22307dec1 causes it to passe -- very likely
    Jérémie's signaling work.

  * `elf/tst-unused-dep.out` (1f393a11f65dcaa1952bdcaf0317a65a5f8aff9d,
    [[!sourceware_PR 13706]], [[!message-id "4F4210C1.1090704@redhat.com"]])

        Unused direct dependencies:
                /home/thomas/tmp/glibc/tschwinge/Roger_Whittaker.build-gcc-4.6-486/dlfcn/libdl.so.2

    As of 8958805c11c741d9211e20612c86271d906c9a0b, this test now passes --
    correct?

Compared to Debian:

    $ bash ~/tmp/glibc/debian/eglibc-2.13/debian/testsuite-checking/convertlog.sh log_test  > log_test.filtered
    $ bash ~/tmp/glibc/debian/eglibc-2.13/debian/testsuite-checking/compare.sh ~/tmp/glibc/debian/eglibc-2.13/debian/testsuite-checking/expected-results-i486-gnu-libc log_test.filtered