Re: WARN_ON_ONCE(!new_owner) within wake_futex_pi() triggered

[Thomas Gleixner]

Heiko,

On Wed, 23 Jan 2019, Heiko Carstens wrote:
> It doesn't look like it does. One occurrence was the one below when
> using commit 7939f8beecf1 (which is post 5.0-rc2) for building the
> kernel:
>
>  WARNING: CPU: 14 PID: 23505 at kernel/futex.c:1483 do_futex+0xa9a/0xc50
>  Kernel panic - not syncing: panic_on_warn set ...
>  CPU: 14 PID: 23505 Comm: ld.so.1 Not tainted 5.0.0-20190116.rc2.git0.7939f8beecf1.300.fc29.s390x+git #1
>  Hardware name: IBM 3906 M04 704 (LPAR)
>  Call Trace:
>  ([<0000000000112e60>] show_stack+0x58/0x70)
>   [<0000000000a671fa>] dump_stack+0x7a/0xa8
>   [<0000000000143f52>] panic+0x11a/0x2d0
>   [<0000000000143db0>] __warn+0xf8/0x118
>   [<0000000000a662f8>] report_bug+0xd8/0x150
>   [<00000000001014ac>] do_report_trap+0xc4/0xe0
>   [<0000000000101680>] illegal_op+0x138/0x150
>   [<0000000000a87270>] pgm_check_handler+0x1c8/0x220
>   [<00000000001e9aea>] do_futex+0xa9a/0xc50
>  ([<00000000001e9c4e>] do_futex+0xbfe/0xc50)
>   [<00000000001ea13c>] compat_sys_futex+0xe4/0x170
>   [<0000000000a86e84>] system_call+0xd8/0x2c8 

Ok. That's another one which I can't spot yet.

    Is that only on S390?
    What's the test which explodes? Kernel build?

Thanks,

	tglx