Created attachment 33400 [details] Example 2: SSE vector load causes SEGV on callback from Xt timer This is essentially a resubmission of bug 47842 "gcc forces 16-byte stack alignment on Solaris i386, when SYSV requires word alignment". As described in the above bug, changes to gcc for Linux x86 cause generated code to assume a 16-byte preferred and incoming stack alignment. However, this behaviour does not conform to the Solaris x86 (32-bit) ABI, which is still based on http://www.sco.com/developers/devspecs/abi386-4.pdf and only specifies that the stack be 32-bit word aligned. PR 47842 was closed due to a lack of test cases. Here, therefore, are two test cases that demonstrate the problem: Example 1: Mixing 32-bit modules compiled with the Solaris Studio 12.3 and gcc: Using: - Solaris Studio compiler from http://www.oracle.com/technetwork/server-storage/solarisstudio/downloads/index-jsp-141149.html - gcc 4.8.0 (stable) or gcc 4.9.0 (unstable) package from http://www.opencsw.org/ or gcc 4.9.1 built from tarball Files: x.c, y.c, build Result: GNU gdb (GDB) 7.6 Copyright (C) 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i386-pc-solaris2.10". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /export/home/justin/tmp/xy...done. (gdb) r Starting program: /export/home/justin/tmp/xy Program received signal SIGSEGV, Segmentation fault. 0x080509db in _mm_set_epi8 (__q00=1 '\001', __q01=1 '\001', __q02=1 '\001', __q03=1 '\001', __q04=1 '\001', __q05=1 '\001', __q06=1 '\001', __q07=1 '\001', __q08=1 '\001', __q09=1 '\001', __q10=1 '\001', __q11=1 '\001', __q12=1 '\001', __q13=1 '\001', __q14=1 '\001', __q15=1 '\001') at /opt/tarantella/lib/gcc/i386-pc-solaris2.10/4.8.0/include/emmintrin.h:602 602 return __extension__ (__m128i)(__v16qi){ (gdb) where #0 0x080509db in _mm_set_epi8 (__q00=1 '\001', __q01=1 '\001', __q02=1 '\001', __q03=1 '\001', __q04=1 '\001', __q05=1 '\001', __q06=1 '\001', __q07=1 '\001', __q08=1 '\001', __q09=1 '\001', __q10=1 '\001', __q11=1 '\001', __q12=1 '\001', __q13=1 '\001', __q14=1 '\001', __q15=1 '\001') at /opt/tarantella/lib/gcc/i386-pc-solaris2.10/4.8.0/include/emmintrin.h:602 #1 _mm_set1_epi8 (__A=1 '\001') at /opt/tarantella/lib/gcc/i386-pc-solaris2.10/4.8.0/include/emmintrin.h:637 #2 test_sse () at x.c:5 #3 0x08050a1b in main (argc=1, argv=0x8047d74) at y.c:5 (gdb) Example 2: libXt timer callback Using: - gcc 4.8.0 (stable) or gcc 4.9.0 (unstable) packages from http://www.opencsw.org/ - or gcc 4.9.1 from tarball File: xt.c Result: The stack becomes only 4-byte aligned on callback from Xt. GNU gdb (GDB) 7.6 Copyright (C) 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i386-pc-solaris2.10". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /export/home/justin/tmp/xt...done. (gdb) r Starting program: /export/home/justin/tmp/xt Program received signal SIGSEGV, Segmentation fault. 0x08050e97 in _mm_set_epi8 (__q00=1 '\001', __q01=1 '\001', __q02=1 '\001', __q03=1 '\001', __q04=1 '\001', __q05=1 '\001', __q06=1 '\001', __q07=1 '\001', __q08=1 '\001', __q09=1 '\001', __q10=1 '\001', __q11=1 '\001', __q12=1 '\001', __q13=1 '\001', __q14=1 '\001', __q15=1 '\001') at /opt/csw/lib/gcc/i386-pc-solaris2.10/4.8.0/include/emmintrin.h:602 602 return __extension__ (__m128i)(__v16qi){ (gdb) info reg ebp ebp 0x8047c74 0x8047c74 (gdb) fr 1 #1 _mm_set1_epi8 (__A=1 '\001') at /opt/csw/lib/gcc/i386-pc-solaris2.10/4.8.0/include/emmintrin.h:637 637 return _mm_set_epi8 (__A, __A, __A, __A, __A, __A, __A, __A, (gdb) info reg ebp ebp 0x8047c74 0x8047c74 (gdb) fr 2 #2 timer_callback (client_data=0x0, id=0x8047d10) at xt.c:10 10 __m128i b = _mm_set1_epi8(1); (gdb) info reg ebp ebp 0x8047c74 0x8047c74 (gdb) fr 3 #3 0xfef46e29 in XtAppProcessEvent () from /usr/lib/libXt.so.4 (gdb) info reg ebp ebp 0x8047d18 0x8047d18 (gdb) fr 4 #4 0x08050efc in main (argc=1, argv=0x8047d74) at xt.c:17 17 XtAppProcessEvent(app, XtIMTimer); (gdb) info reg ebp ebp 0x8047d4c 0x8047d4c (gdb) I believe the problem was fixed for the limited case of Solaris 9 x86 in bug 60107. However, the analysis for this fix seems slightly off. It infers that, because Solaris 10 creates outgoing thread stacks aligned on 16 bytes, the 32-bit ABI has changed to 16-byte stack alignment on this platform, which isn't correct. I suggest -mincoming-stack-boundary=2 should be the default for all 32-bit Solaris binaries. Workarounds: 1. __attribute__((force_align_arg_pointer)) at all entry points to gcc generated code, 2. Compile all gcc code with -mincoming-stack-boundary=2.
Created attachment 33401 [details] Example 2: Preprocessed source
Created attachment 33402 [details] Example 1: gcc compiled module performing sse vector load
Created attachment 33403 [details] Example 1: Solaris studio compiled module: main()
Created attachment 33404 [details] Example 1: preprocessed source
Created attachment 33405 [details] Example 1: build script
I've been seeing the same issue in PR middle-end/61949, but only on Solaris 10, not S11, and the failures have been intermittent (i.e. happened during one bootstrap, but were gone a week later). Regarding > I believe the problem was fixed for the limited case of Solaris 9 x86 in bug > 60107. However, the analysis for this fix seems slightly off. It infers that, > because Solaris 10 creates outgoing thread stacks aligned on 16 bytes, the > 32-bit ABI has changed to 16-byte stack alignment on this platform, which isn't > correct. I believe the i386 psABI is irrelevant here: while it requires word alignment, it doesn't preclude that Solaris guarantees a stricter alignment, which from what I've seen both S10 and S11 do. > I suggest -mincoming-stack-boundary=2 should be the default for all 32-bit > Solaris binaries. Before making any changes in this area, I'd like word from the responsible libc engineer (Roger Faulkner probably) what various Solaris versions do and don't guarantee. Rainer
FWIW, I recommended to Sun in Mar 2006 that the kernel should ensure 16-byte alignment for both signal handlers and process startup (apparently this resulted in Sun bug 6397812, "Problem with stack alignment for signal delivery on AMD64"). (This does not of course mean that the ABI ended up with such an alignment requirement at interface boundaries in general.)
GCC 5.1 has been released.
GCC 5.2 is being released, adjusting target milestone to 5.3.
GCC 5.3 is being released, adjusting target milestone.
*** Bug 61949 has been marked as a duplicate of this bug. ***
Mine, received confirmation that only 4-byte stack alignment is guaranteed on 32-bit Solaris/x86 from the Solaris and Studio groups in Oracle. Rainer
Author: ro Date: Mon Mar 7 09:51:31 2016 New Revision: 234022 URL: https://gcc.gnu.org/viewcvs?rev=234022&root=gcc&view=rev Log: Only assume 4-byte stack alignment on 32-bit Solaris/x86 (PR target/62281) PR target/62281 * config/i386/sol2.h (STACK_REALIGN_DEFAULT): Define. Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/sol2.h
Fixed for 6.1.
Author: ro Date: Mon Mar 14 09:56:47 2016 New Revision: 234179 URL: https://gcc.gnu.org/viewcvs?rev=234179&root=gcc&view=rev Log: Only assume 4-byte stack alignment on Solaris/x86 (PR target/62281) Backport from mainline 2016-03-07 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> PR target/62281 * config/i386/sol2.h (STACK_REALIGN_DEFAULT): Define. Modified: branches/gcc-5-branch/gcc/ChangeLog branches/gcc-5-branch/gcc/config/i386/sol2.h
Author: ro Date: Mon Mar 14 10:03:12 2016 New Revision: 234180 URL: https://gcc.gnu.org/viewcvs?rev=234180&root=gcc&view=rev Log: Only assume 4-byte stack alignment on Solaris/x86 (PR target/62281) Backport from mainline: 2016-03-07 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> PR target/62281 * config/i386/sol2.h (STACK_REALIGN_DEFAULT): Define. Revert: 2014-02-11 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> PR libgomp/60107 * config/i386/sol2-9.h: New file. * config.gcc (i[34567]86-*-solaris2* | x86_64-*-solaris2.1[0-9]*, *-*-solaris2.9*): Use it. Removed: branches/gcc-4_9-branch/gcc/config/i386/sol2-9.h Modified: branches/gcc-4_9-branch/gcc/ChangeLog branches/gcc-4_9-branch/gcc/config.gcc branches/gcc-4_9-branch/gcc/config/i386/sol2.h
Fixed for GCC 4.9.4, 5.4, 6.1.
Author: meissner Date: Mon Mar 14 18:18:45 2016 New Revision: 234188 URL: https://gcc.gnu.org/viewcvs?rev=234188&root=gcc&view=rev Log: [gcc] 2016-03-14 Michael Meissner <meissner@linux.vnet.ibm.com> Backport from mainline 2016-03-11 Michael Meissner <meissner@linux.vnet.ibm.com> PR target/70131 * config/rs6000/rs6000.md (round32<mode>2_fprs): Do not do the optimization if we have direct move. (roundu32<mode>2_fprs): Likewise. 2016-03-14 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> Backport from mainline 2016-03-07 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> PR target/62281 * config/i386/sol2.h (STACK_REALIGN_DEFAULT): Define. 2016-03-10 Ulrich Weigand <Ulrich.Weigand@de.ibm.com> PR target/70168 * config/rs6000/rs6000.c (rs6000_expand_atomic_compare_and_swap): Handle overlapping retval and newval. [gcc/testsuite] 2016-03-14 Michael Meissner <meissner@linux.vnet.ibm.com> Backport from mainline 2016-03-11 Michael Meissner <meissner@linux.vnet.ibm.com> PR target/70131 * gcc.target/powerpc/ppc-round2.c: New test. 2016-03-14 Dominique d'Humieres <dominiq@lps.ens.fr> PR fortran/45076 gfortran.dg/prof/prof.exp: New script. gfortran.dg/prof/dynamic_dispatch_6.f03: New test. Added: branches/ibm/gcc-5-branch/gcc/testsuite/gcc.target/powerpc/ppc-round2.c - copied unchanged from r234186, branches/gcc-5-branch/gcc/testsuite/gcc.target/powerpc/ppc-round2.c branches/ibm/gcc-5-branch/gcc/testsuite/gfortran.dg/prof/ - copied from r234186, branches/gcc-5-branch/gcc/testsuite/gfortran.dg/prof/ Modified: branches/ibm/gcc-5-branch/gcc/ChangeLog branches/ibm/gcc-5-branch/gcc/DATESTAMP branches/ibm/gcc-5-branch/gcc/config/i386/sol2.h branches/ibm/gcc-5-branch/gcc/config/rs6000/rs6000.c branches/ibm/gcc-5-branch/gcc/config/rs6000/rs6000.md branches/ibm/gcc-5-branch/gcc/testsuite/ChangeLog