glibc issues with --enable-kernel=2.6.22.5

[bigorneault]

When building glibc 2.12.1 and 2.12.2 on x86_64 linux with --enable-kernel=2.6.22.5, the following tests fail:

make[2]: *** [/build/glibc-build/nptl/tst-rwlock6.out] Error 1
make[2]: *** [/build/glibc-build/nptl/tst-rwlock7.out] Error 1
make[2]: *** [/build/glibc-build/nptl/tst-rwlock9.out] Error 1
make[2]: *** [/build/glibc-build/nptl/tst-rwlock11.out] Error 1
make[2]: *** [/build/glibc-build/nptl/tst-rwlock12.out] Error 11
make[2]: *** [/build/glibc-build/nptl/tst-rwlock14.out] Error 1
make[2]: *** [/build/glibc-build/nptl/tst-abstime.out] Error 1

This issues does not occur on i686. If I build glibc with --enable-kernel=2.6.29 or later, all tests pass.

[bigorneault]

killing the ASSUME_PRIVATE_FUTEX define seems to fix the problem. See the patch.

[bigorneault]

kill ASSUME_PRIVATE_FUTEX

[Bryan Kadzban]

Can you tell what the ASSUME_PRIVATE_FUTEX define is changing? I assume that since you say it works with 2.6.29, there's some other defined ASSUME_* symbol that affects the generated code... Can you tell why the tests are failing? (The logs should be helpful.)

Does it work to use 2.6.22 instead of 2.6.22.5? (Why are we using 2.6.22.5 anyway? That's not functionally any different from 2.6.22, it just has some bugfixes.)

[bdubbs@…]

I'm just guessing, but I suspect the failed tests depend on the kernel configuration.

Symbol: FUTEX [=y]                                                                             
 Prompt: Enable futex support                                                                   
   Defined at init/Kconfig:903                                                                  
     Depends on: EMBEDDED [=y]                                                                    
     Location:                                                                                    
       -> General setup                                                                           
         -> Configure standard kernel features (for small systems) (EMBEDDED [=y])                
     Selects: RT_MUTEXES [=y]

The 2.6.22.5 version is what we specify as the minimum.