Solaris 11/x86: wrong STACKBOTTOM

[wangp]

Hi, it appears the determination of STACKBOTTOM does not work on Solaris 11/x86.

I tested with the latest 'master' branch. Note that I disable threads. make check passes when threads are enabled.

# uname -a
SunOS solaris 5.11 11.2 i86pc i386 i86pc

# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/gcc/4.8/lib/gcc/i386-pc-solaris2.11/4.8.2/lto-wrapper
Target: i386-pc-solaris2.11
Configured with: /builds/hudson/workspace/nightly-update/build/i386/components/gcc48/gcc-4.8.2/configure CC=/usr/gcc/4.7/bin/gcc CXX=/usr/gcc/4.7/bin/g++ --prefix=/usr/gcc/4.8 --mandir=/usr/gcc/4.8/share/man --bindir=/usr/gcc/4.8/bin --libdir=/usr/gcc/4.8/lib --sbindir=/usr/gcc/4.8/sbin --infodir=/usr/gcc/4.8/share/info --libexecdir=/usr/gcc/4.8/lib --enable-languages=c,c++,fortran,objc --enable-shared --with-gmp-include=/usr/include/gmp --with-mpfr-include=/usr/include/mpfr --without-gnu-ld --with-ld=/usr/bin/ld --with-gnu-as --with-as=/usr/gnu/bin/as CFLAGS='-g -O2  -mtune=opteron -march=opteron' CXXFLAGS='-g -O2 -mtune=opteron -march=opteron'
Thread model: posix
gcc version 4.8.2 (GCC) 

# autoreconf -vif
# automake --add-missing
# ./configure --disable-threads
# gmake -j4
# gmake check
...
gmake  check-TESTS
gmake[2]: Entering directory `/root/bdwgc'
/bin/sh: line 10: 10801: Memory fault(coredump)
FAIL: cordtest
Switched to incremental mode
Emulating dirty bits with mprotect/signals
/bin/sh: line 10: 10810: Memory fault(coredump)
FAIL: gctest
/bin/sh: line 10: 10819: Memory fault(coredump)
FAIL: leaktest
/bin/sh: line 10: 10828: Memory fault(coredump)
FAIL: middletest
/bin/sh: line 10: 10837: Memory fault(coredump)
FAIL: smashtest
/bin/sh: line 10: 10846: Memory fault(coredump)
FAIL: hugetest
/bin/sh: line 10: 10855: Memory fault(coredump)
FAIL: realloc_test
/bin/sh: line 10: 10864: Memory fault(coredump)
FAIL: staticrootstest
/bin/sh: line 10: 10873: Memory fault(coredump)
FAIL: disclaim_test
/bin/sh: line 10: 10882: Memory fault(coredump)
FAIL: disclaim_bench
==========================================
10 of 10 tests failed
Please report to [email protected]
==========================================

It seems STACKBOTTOM is wrong. make check passes after applying this hack (in the #ifdef I386 block):

diff --git a/include/private/gcconfig.h b/include/private/gcconfig.h
index f4935b4..a287b4b 100644
--- a/include/private/gcconfig.h
+++ b/include/private/gcconfig.h
@@ -1265,7 +1265,8 @@
 /*      old executables.                                                */
 /*      HEURISTIC2 probably works, but this appears to be preferable.   */
 #       include <sys/vm.h>
-#       define STACKBOTTOM ((ptr_t)USRSTACK)
+//#       define STACKBOTTOM ((ptr_t)USRSTACK)
+#      define HEURISTIC2
 /* At least in Solaris 2.5, PROC_VDB gives wrong values for dirty bits. */
 /* It appears to be fixed in 2.8 and 2.9.                               */
 #       ifdef SOLARIS25_PROC_VDB_BUG_FIXED

Perhaps the I386 block requires the same code as for X86_64 and SPARC? i.e. this stuff

/*      # define STACKBOTTOM ((ptr_t)(_start)) worked through 2.7,      */                                             
/*      but reportedly breaks under 2.8.  It appears that the stack     */                                             
/*      base is a property of the executable, so this should not break  */                                             
/*      old executables.                                                */                                             
/*      HEURISTIC2 probably works, but this appears to be preferable.   */                                             
/*      Apparently USRSTACK is defined to be USERLIMIT, but in some     */                                             
/*      installations that's undefined.  We work around this with a     */                                             
/*      gross hack:                                                     */                                             
#       include <sys/vmparam.h>
#       ifdef USERLIMIT
          /* This should work everywhere, but doesn't.  */                                                             
#         define STACKBOTTOM ((ptr_t)USRSTACK)                                                                         
#       else
#         define HEURISTIC2                                                                                            
#       endif

[wangp]

I've tested the HEURISTIC2 change on a bigger test case, the Mercury compiler. With the change, it works as expected.

[ivmai]

The fix merged to master - 81cae56
Please check.

[wangp]

Thanks, Ivan. It looks fine.