Re: [RFC6 PATCH v6 00/21] ILP32 for ARM64 - LTP results

[Zhangjian (Bamvor)]

Hi, Andrew

On 2016/4/28 5:15, Andrew Pinski wrote:
> On Wed, Apr 27, 2016 at 12:30 AM, Andrew Pinski <pinskia@xxxxxxxxx> wrote:
> > On Fri, Apr 22, 2016 at 8:37 PM, Zhangjian (Bamvor)
> > <bamvor.zhangjian@xxxxxxxxxx> wrote:
> > > Hi, Yury
> > >
> > >
> > > On 2016/4/6 6:44, Yury Norov wrote:
> > > > There are about 20 failing tests of 782 in lite scenario.
> > > > float_bessel
> > > > float_exp_log
> > > > float_iperb
> > > > float_power
> > > > float_trigo
> > > > pipeio_1
> > > > pipeio_3
> > > > pipeio_5
> > > > pipeio_8
> > > > abort01
> > > > clone02
> > > > kill11
> > > > mmap16
> > > > open12
> > > > pause01
> > > > rename11
> > > > rmdir02
> > > > umount2_01
> > > > umount2_02
> > > > umount2_03
> > > > utime06
> > > > mtest06
> > > >
> > > > The list is rough because some tests fail not every time.
> > > >
> > > > Tests abort01 and kill11 fail for lp64 too, so maybe there's
> > > > a reason unrelated to ilp32 itself.
> > > >
> > > > float_xxx tests fail because they call unwind() from signal context,
> > > > and GCC for ilp32 has problem with it, as Andrew told.
> > >
> > > Is there some progress about this issue. When we talk about unwind
> > > functions, do you mean the function in libgcc?
> > >
> > > We encountered another issue(abort not segfault) which also called
> > > pthread_cancel(). The test code is in the attachment. Here is the
> > > backtrace:
> >
> > Yes this was a known issue I knew about.  I have a patch GCC to fix
> > this.  Basically REG_VALUE_IN_UNWIND_CONTEXT needs to be defined while
> > building libgcc to support the correct unwind information.
> > I will be posting a GCC patch to fix this tomorrow.  This was a bug
> > even in the original set of ilp32 patches.  I only finally was able to
> > sit down and fix it today.
>
> Here is the link to the GCC patch which I said was going to submit today:
> https://gcc.gnu.org/ml/gcc-patches/2016-04/msg01726.html
It works for me. Both float_xx in ltp and my pthread_cancel testcase is
pass.

Regards

Bamvor

> Thanks,
> Andrew
>
> > Thanks,
> > Andrew
> >
> > > ```
> > > Program received signal SIGABRT, Aborted.
> > > [Switching to Thread 0xf77ee330 (LWP 2958)]
> > > 0x000000000040f5bc in raise (sig=sig@entry=6)
> > >      at ../sysdeps/unix/sysv/linux/raise.c:55
> > > 55      ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
> > > (gdb) bt
> > > #0  0x000000000040f5bc in raise (sig=sig@entry=6)
> > >      at ../sysdeps/unix/sysv/linux/raise.c:55
> > > #1  0x000000000040f884 in abort () at abort.c:89
> > >
> > > #2  0x00000000004073b4 in uw_update_context_1 (
> > >      context=context@entry=0xf77ec820, fs=fs@entry=0xf77ebec8)
> > > at /home/GCC-Build/p660/p660_build_dir/src/gcc-4.9/libgcc/unwind-dw2.c:1430
> > >
> > > #3  0x00000000004078c0 in uw_update_context
> > > (context=context@entry=0xf77ec820,
> > >      fs=fs@entry=0xf77ebec8)
> > >     at
> > > /home/GCC-Build/p660/p660_build_dir/src/gcc-4.9/libgcc/unwind-dw2.c:1506
> > > #4  0x0000000000407a9c in uw_advance_context (fs=0xf77ebec8,
> > >      context=0xf77ec820)
> > >      at
> > > /home/GCC-Build/p660/p660_build_dir/src/gcc-4.9/libgcc/unwind-dw2.c:1529
> > > #5  _Unwind_ForcedUnwind_Phase2 (exc=exc@entry=0xf77ee580,
> > >      context=context@entry=0xf77ec820)
> > >      at /home/GCC-Build/p660/p660_build_dir/src/gcc-4.9/libgcc/unwind.inc:185
> > > #6  0x0000000000408228 in _Unwind_ForcedUnwind (exc=0xf77ee580,
> > >      stop=stop@entry=0x405440 <unwind_stop>, stop_argument=0xf77eddd8)
> > >      at /home/GCC-Build/p660/p660_build_dir/src/gcc-4.9/libgcc/unwind.inc:207
> > > #7  0x00000000004055c4 in __pthread_unwind (buf=<optimized out>)
> > >      at unwind.c:126
> > > #8  0x00000000004050b4 in __do_cancel () at ./pthreadP.h:283
> > > #9  sigcancel_handler (sig=<optimized out>, si=<optimized out>,
> > >      ctx=<optimized out>) at nptl-init.c:225
> > > ---Type <return> to continue, or q <return> to quit---
> > > #10 <signal handler called>
> > >
> > > #11 0x0000000000000000 in ?? ()
> > >
> > > #12 0x0000000000423084 in __select (nfds=-66661, readfds=<optimized out>,
> > >      writefds=<optimized out>, exceptfds=<optimized out>, timeout=0x0)
> > >      at ../sysdeps/unix/sysv/linux/generic/select.c:45
> > > #13 0x0000000000400604 in TEST_TaskDelay (
> > >      uiMillSecs=<error reading variable: can't compute CFA for this frame>)
> > >      at test-cancel.c:18
> > > #14 0x0000000000400680 in printids (
> > >      s=<error reading variable: can't compute CFA for this frame>)
> > >      at test-cancel.c:38
> > > #15 0x00000000004006d0 in thr_fn (
> > >      arg=<error reading variable: can't compute CFA for this frame>)
> > >      at test-cancel.c:49
> > > #16 0x0000000000401b28 in start_thread (arg=0x4a3000) at
> > > pthread_create.c:335
> > > #17 0x0000000000401b28 in start_thread (arg=0x4a3000) at
> > > pthread_create.c:335
> > > Backtrace stopped: previous frame identical to this frame (corrupt stack?)
> > > ```
> > >
> > > Such abort is raise by the following code:
> > > ```
> > > static void
> > > uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState
> > > *fs)
> > > {
> > > //...
> > >    /* Compute this frame's CFA.  */
> > >    switch (fs->regs.cfa_how)
> > >      {
> > >      case CFA_REG_OFFSET:
> > >        cfa = _Unwind_GetPtr (&orig_context, fs->regs.cfa_reg);
> > >        cfa += fs->regs.cfa_offset;
> > >        break;
> > >
> > >      case CFA_EXP:
> > >        {
> > >          const unsigned char *exp = fs->regs.cfa_exp;
> > >          _uleb128_t len;
> > >
> > >          exp = read_uleb128 (exp, &len);
> > >          cfa = (void *) (_Unwind_Ptr)
> > >            execute_stack_op (exp, exp + len, &orig_context, 0);
> > >          break;
> > >        }
> > >
> > >      default:
> > >        gcc_unreachable ();
> > >      }
> > >    context->cfa = cfa;
> > > //...
> > > }
> > > ``
> > >
> > > Any suggestion is appreciated.
> > >
> > > CC gcc mailing list. Sorry if it is off topic.
> > >
> > > Regards
> > >
> > > Bamvor
> > >
> > >
> > >
> > >
> > > > pipeio_x tests are very unstable and may fail randomly. I strongly
> > > > suspect race conditions, as they all work like a charm if pinned to
> > > > single CPU with taskset. Probably, race is the reason of clone02 too.
> > > > Though I'm not sure, is the race in kernel, glibc or test itself.
> > > >
> > > > But I know for sure that pause01 fails due to test design:
> > > >          if (setitimer(ITIMER_REAL, &it, NULL)) // For 1000us
> > > >                  tst_brkm(TBROK | TERRNO, NULL, "setitimer() failed");
> > > >
> > > >          TEST(pause());
> > > >
> > > > As setitimer() and pause() calls are not atomic, alarm may come before
> > > > pause()
> > > > is called, and be silently dropped by the handler. Next pause() call hangs
> > > > test forever. I already reported to LTP list.
> > > >
> > > > open12, rename11, rmdir02, mmap16, mtest06 - all call mkfs tool, and it
> > > > returns
> > > > error code. I didn't investigate it much yet.
> > > >
> > > > umount02_x, utime06 - cannot reproduce out of scenario, even run it in
> > > > infinite
> > > > loop - they work fine.
> > > >
> > > > Full test log is attached.
> > > >
> > > > Yury