Hi Jeff,
> On 04/06/2016 05:12 AM, Rainer Orth wrote:
>> I've finally gotten around to analyzing this testsuite failure on 32-bit
>> Solaris/x86:
>>
>> FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -O1 -fcilkplus execution test
>> FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -O3 -fcilkplus execution test
>> FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -g -O2 -fcilkplus execution test
>> FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -g -fcilkplus execution test
>>
>> The testcase aborts like this:
>>
>> Thread 2 received signal SIGABRT, Aborted.
>> [Switching to Thread 1 (LWP 1)]
>> 0xfe3ba3c5 in __lwp_sigqueue () from /lib/libc.so.1
>> (gdb) where
>> #0 0xfe3ba3c5 in __lwp_sigqueue () from /lib/libc.so.1
>> #1 0xfe3b2d4f in thr_kill () from /lib/libc.so.1
>> #2 0xfe2f64da in raise () from /lib/libc.so.1
>> #3 0xfe2c93ee in abort () from /lib/libc.so.1
>> #4 0xfe525b37 in _Unwind_Resume (exc=0x80a75a0)
>> at /vol/gcc/src/hg/trunk/local/libgcc/unwind.inc:234
>> #5 0xfe783b85 in __cilkrts_gcc_rethrow (sf=0xfeffdb00)
>> at /vol/gcc/src/hg/trunk/local/libcilkrts/runtime/except-gcc.cpp:589
>> #6 0xfe77f0ea in __cilkrts_rethrow (sf=0xfeffdb00)
>> at /vol/gcc/src/hg/trunk/local/libcilkrts/runtime/cilk-abi.c:548
>> #7 0x080513a3 in my_test ()
>> at
>> /vol/gcc/src/hg/trunk/local/gcc/testsuite/g++.dg/cilk-plus/CK/catch_exc.cc:38
>> #8 0x080515bd in main ()
>> at
>> /vol/gcc/src/hg/trunk/local/gcc/testsuite/g++.dg/cilk-plus/CK/catch_exc.cc:62
>>
>> The gcc_assert in _Unwind_Resume triggers since
>> _Unwind_RaiseException_Phase2 returned _URC_FATAL_PHASE2_ERROR. I found
>> that x86_fallback_frame_state had been invoked for this pc:
>>
>> 0xfe77218e <__cilkrts_rethrow+30>: add $0x10,%esp
>>
>> and returned _URC_END_OF_STACK, which is totally unexpected since
>> _Unwind_Find_FDE should have found it. __cilkrts_rethrow is defined in
>> libcilkrts/cilk-abi.o, but in the 32-bit case EH info is missing:
>>
>> 32-bit:
>>
>> ro@fuego 339 > elfdump -u .libs/libcilkrts.so|grep rethrow
>> 0x18def 0x3558c __cilkrts_gcc_rethrow
>> [0x11fc] initloc: 0x18def [ sdata4 pcrel ] __cilkrts_gcc_rethrow
>>
>> 64-bit:
>>
>> ro@fuego 341 > elfdump -u amd64/libcilkrts/.libs/libcilkrts.so|grep rethrow
>> 0x1c639 0x2010 __cilkrts_rethrow
>> 0x2388b 0x5510 __cilkrts_gcc_rethrow
>> [0x488] initloc: 0x1c639 [ sdata4 pcrel ] __cilkrts_rethrow
>> [0x3988] initloc: 0x2388b [ sdata4 pcrel ] __cilkrts_gcc_rethrow
>>
>> I traced this to -funwind-tables bein set on 32-bit Linux/x86, while it
>> is unset on 32-bit Solaris/x86 due to
>>
>> i386/i386.c (ix86_option_override_internal):
>>
>> if (opts->x_flag_asynchronous_unwind_tables == 2)
>> opts->x_flag_asynchronous_unwind_tables = !USE_IX86_FRAME_POINTER;
>>
>> where i386/sol2.h has
>>
>> #define USE_IX86_FRAME_POINTER 1
>>
>> while the default is 0.
>>
>> As expected, compiling libcilkrts with -funwind-tables (which is a no-op
>> on Linux/x86, Linux/x86_64, and Solaris/amd64) makes the failure go
>> away.
>>
>> I'm uncertain if this is ok for mainline at this stage or has to wait
>> for gcc-7. Once it goes into mainline, it's probably worth a backport
>> to all active release branches.
>>
>> Thoughts?
>>
>> Rainer
>>
>>
>> 2016-04-04 Rainer Orth <r...@cebitec.uni-bielefeld.de>
>>
>> PR target/60290
>> * Makefile.am (GENERAL_FLAGS): Add -funwind-tables.
>> * Makefile.in: Regenerate.
> OK. Thanks for tracking this down, including verification that the
> difference between Solaris and Linux is the latter having -funwind-tables
> on by default.
thanks, installed. About eventual backports to the 5 and 6 (after 6.1
is released) and maybe even 4.9 branches?
Rainer
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Rainer Orth, Center for Biotechnology, Bielefeld University
