Re: armv7-on-aarch64 stuck at urdlck

From: Michal Meloun <meloun.michal_at_gmail.com>
Date: Tue, 23 Jul 2024 13:56:49 UTC

On 23.07.2024 11:36, Konstantin Belousov wrote:
> On Tue, Jul 23, 2024 at 09:53:41AM +0200, Michal Meloun wrote:
>> The good news is that I'm finally able to generate a working/locking
>> test case.  The culprit (at least for me) is if "-mcpu" is used when
>> compiling libthr (e.g. indirectly injected via CPUTYPE in /etc/make.conf).
>> If it is not used, libthr is broken (regardless of -O level or debug/normal
>> build), but -mcpu=cortex-a15 will always produce a working libthr.
> 
> I think this is very significant progress.
> 
> Do you plan to drill down more to see what is going on?

Sure. Fortunately, I have some free time now. I've just almost finished 
a two-years project (unrelated to FBSD or computers) that took up all my 
time.


Another symptom is that:

Breakpoint 2.2, _umtx_op_err (obj=0x20135cc0, op=UMTX_OP_RW_RDLOCK,
  val=0, uaddr=0x0,  uaddr2=0x0) at /usr/src/lib/libsys/_umtx_op_err.c:36
where  obj=0x20135cc0 --->
  {rw_state = URWLOCK_WRITE_OWNER , rw_flags = 2,
   rw_blocked_readers = 0, rw_blocked_writers = 0,
   rw_spare = {0, 0, 0, 0}}


always return EINTR.