Created attachment 290923 [details]
Output of "rpmbuild -ba --target i686,i386 glibc.spec"

Jakub, I'm seeing the same with gcc-4.3.0-0.5...

I'm still seeing the same when building glibc-2.7.90-4 by using gcc-4.3.0-0.6

Oh, same with gcc-4.3.0-0.7 and glibc-2.7.90-6 as well as in a local mock.

Jakub? Roland?

Those crashes are not coming up in the koji builds.
Maybe experiment with different kernels to see if that affects this showing up.

Roland, is it enough to switch kernel-headers or should I completely change
the kernel including reboots etc.?

I was referring to the kernel running when you do 'make check', not to the
headers used to build glibc.

Roland, I can see this with any F8 kernel, e.g. 2.6.24.3-12.fc8. I didn't try all 
Rawhide kernels yet, but it seems only to succeed on a RHEL5 kernel, which is just 
horribly wrong then. Can you please really have a closer look to it?

I think, I know why this not shows up in mockbuild, because of mock! :-( So here
are the parallels visible for me:

Mockbuild (part a):
make -s subdir=rtkaio -C rtkaio ..=../ tests
make[2]: Entering directory `/builddir/build/BUILD/glibc-20080305T0857/rtkaio'
failed to create a shared memory object: shm_open: Function not implemented
make[2]: Leaving directory `/builddir/build/BUILD/glibc-20080305T0857/rtkaio'

My build without mock (part a):
make -s subdir=rtkaio -C rtkaio ..=../ tests
make[2]: Entering directory `/usr/src/rpm/BUILD/glibc-20080305T0857/rtkaio'
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl/rtkaio/tst-aiod.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl/rtkaio/tst-aiod64.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl/rtkaio/tst-aiod3.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl/rtkaio/tst-aiod4.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl/rtkaio/tst-aiod5.out]
Error 1
make[2]: Target `tests' not remade because of errors.
make[2]: Leaving directory `/usr/src/rpm/BUILD/glibc-20080305T0857/rtkaio'
make[1]: *** [rtkaio/tests] Error 2


Mockbuild (part b):
make -s subdir=rtkaio -C rtkaio ..=../ tests
make[2]: Entering directory `/builddir/build/BUILD/glibc-20080305T0857/rtkaio'
make[2]: Leaving directory `/builddir/build/BUILD/glibc-20080305T0857/rtkaio'
make[2]: Entering directory `/builddir/build/BUILD/glibc-20080305T0857/rtkaio'
failed to create a shared memory object: shm_open: Function not implemented
make[2]: Leaving directory `/builddir/build/BUILD/glibc-20080305T0857/rtkaio'

My build without mock (part a):
make -s subdir=rtkaio -C rtkaio ..=../ tests
make[2]: Entering directory `/usr/src/rpm/BUILD/glibc-20080305T0857/rtkaio'
make[2]: Leaving directory `/usr/src/rpm/BUILD/glibc-20080305T0857/rtkaio'
make[2]: Entering directory `/usr/src/rpm/BUILD/glibc-20080305T0857/rtkaio'
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-aiod3.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-aiod5.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-aiod4.out]
Error 1
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-cpuclock1.out]
Error 1
Didn't expect signal from child: got `Segmentation fault'
Didn't expect signal from child: got `Segmentation fault'
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-aiod64.out]
Error 1
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-aiod.out]
Error 1
make[2]: ***
[/usr/src/rpm/BUILD/glibc-20080305T0857/build-i686-linuxnptl-nosegneg/rtkaio/tst-cpuclock2.out]
Error 1
make[2]: Target `tests' not remade because of errors.
make[2]: Leaving directory `/usr/src/rpm/BUILD/glibc-20080305T0857/rtkaio'
make[1]: *** [rtkaio/tests] Error 2

For me it seems, that it doesn't change anything when 'make check' is executed 
with another kernel running. Is it possible, that mock doesn't support shm_open?

I have added support for shm to mock in git. Can you please test this version to
see if it fixes your problem?

Instructions on how to download and compile new version are here:
https://fedorahosted.org/mock

Using the latest mock, I'm now able to see this segmentation faults in mock as 
well, thanks to Ricky Zhou for testing this on a more fast machine.

Okay...work for you, Roland and/or Jakub -- "make check" of glibc is now always
segfaulting for these special parts in mock...upgrading to blocker, as this seems
more critical to me now.

Created attachment 297377 [details]
build.log

Jakub, ping on this issue, do you think it's reasonable to have a fix for Fedora
9 or should we punt to 10?

Got to test this on i686 kernel and this is a kernel bug.  See following small
testcase.
gcc -m32 -O2 -o io_getevents_bug io_getevents_bug.c
./io_getevents_bug

For i?86, glibc (and other userland stuff) assumes that syscalls only clobber
%eax register (with the return value), all other registers have their value
preserved.
I don't have access to many i686 kernels anymore, so all I could verify is that on
2.6.23.12-52.fc7.x86_64 and current RHEL5.2 beta x86_64 kernels %esi is preserved
across io_getevents int $0x80, but in 2.6.24.4-64.fc8.i686 and as ajax tested
for me also in 2.6.25-0.204.rc8.git4.fc9.i686 this prints:
Bug - %esi modified by io_getevents syscall, 2 * sizeof (struct kio_event) has
been added
(where instead of 2 it can print 1 through 10, basically io_getevents changes
%esi to point after the last struct kio_event).

This seems pretty serious bug, could kernel folks please investigate ASAP
at least which syscalls are broken in which kernels?

Created attachment 302012 [details]
io_getevents_bug.c

Looking at kernel code and googling around, this smells like
http://kerneltrap.org/node/6521, except that in this case it isn't a sibcall
that causes a problem, but probably high register presure together with inlining
the read_events function which increments the events argument.
As a quick hack adding noinline attribute to read_events could very likely help
(just guessing, haven't tried that) and guess we should revive PR27234.

We definitely need that ABI-changing attribute to solve this sanely in the future.

I reproduced a build with the problem using vanilla upstream sources (and f8's
compiler).  I tried an asm hack akin to prevent_tail_call(), to keep the args
live at the end of the function, and that changed code generation not to tickle
the problem.  I'll turn it into a general macro hack and send it upstream.

This is fixed in 2.6.25-rc9. A subset of that fix is in 2.6.24.4-80.fc8