Re: [PATCH 0/5] linux-user/s390x: Fix psw.mask handling in signals

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> The PSW_MASK_CC component of psw.mask was not handled properly
> in the creation or restoration of signal frames.

Still seeing issues running on s390x machine:

  05:00:29 [ajb@qemu01:~/l/q/b/debug] s390x/signal-fixes|… 38 + retry.py -n 100 -c -- ./qemu-s390x ./tests/tcg/s390x-linux-user/signals
  ...
  ...
  Results summary:
  0: 62 times (62.00%), avg time 2.253 (0.00 varience/0.00 deviation)
  -11: 38 times (38.00%), avg time 0.251 (0.00 varience/0.00 deviation)
  Ran command 100 times, 62 passes

I don't get much from the backtrace, maybe the atomic triggered the seg?

  #0  0x0000000001016244 in vfprintf ()
  [Current thread is 1 (Thread 0x4001001910 (LWP 27308))]
  (gdb) bt
  #0  0x0000000001016244 in vfprintf ()
  #1  0x000000000101d484 in printf ()
  #2  0x0000000001000b2e in background_thread_func (arg=0x10a3620) at /home/ajb/lsrc/qemu.git/tests/tcg/multiarch/signals.c:65
  #3  0x0000000001003150 in start_thread (arg=0x4001001910) at pthread_create.c:463
  #4  0x0000000001035b40 in thread_start ()
  (gdb) frame 2
  #2  0x0000000001000b2e in background_thread_func (arg=0x10a3620) at /home/ajb/lsrc/qemu.git/tests/tcg/multiarch/signals.c:65
  65          printf("thread%d: started\n", job->number);
  (gdb) info locals
  job = 0x10a3620
  (gdb) p job
  $1 = (ThreadJob *) 0x10a3620
  (gdb) p job->number
  $2 = 0
  (gdb) frame 0
  #0  0x0000000001016244 in vfprintf ()
  (gdb) x/5i $pc
  => 0x1016244 <vfprintf+1316>:   asi     224(%r11),1
     0x101624a <vfprintf+1322>:   cgijne  %r1,0,0x1017570 <vfprintf+6224>
     0x1016250 <vfprintf+1328>:   lg      %r1,336(%r11)
     0x1016256 <vfprintf+1334>:   lghi    %r3,37
     0x101625a <vfprintf+1338>:   aghik   %r6,%r1,1
  (gdb) p/x $r11
  $3 = 0x4001000708
  (gdb) p/x $r11 + 224
  $4 = 0x40010007e8
  (gdb) x/1g $4
  0x40010007e8:   0x0000000000000000
  (gdb)

However running on x86 backend everything seems to be fine.

  Results summary:
  0: 200 times (100.00%), avg time 2.255 (0.00 varience/0.00 deviation)
  Ran command 200 times, 200 passes

>
>
> r~
>
>
> Richard Henderson (5):
>   target/s390x: Expose load_psw and get_psw_mask to cpu.h
>   target/s390x: Do not modify cpu state in s390_cpu_get_psw_mask
>   target/s390x: Improve s390_cpu_dump_state vs cc_op
>   target/s390x: Use s390_cpu_{set_psw,get_psw_mask} in gdbstub
>   linux-user/s390x: Save and restore psw.mask properly
>
>  target/s390x/cpu.h         |   3 ++
>  target/s390x/internal.h    |   5 --
>  linux-user/s390x/signal.c  |  37 ++++++++++++--
>  target/s390x/cc_helper.c   |   2 +-
>  target/s390x/excp_helper.c |  28 +++++-----
>  target/s390x/gdbstub.c     |  15 +-----
>  target/s390x/helper.c      | 101 ++++++++++++++++++++-----------------
>  target/s390x/sigp.c        |   3 +-
>  8 files changed, 110 insertions(+), 84 deletions(-)

-- 
Alex Bennée