[Bug middle-end/54313] New: [4.8 Regression] GCC fails to bootstrap with MALLOC_PERTURB – Segfault in bitmap_obstack_free

[Bug middle-end/54313] New: [4.8 Regression] GCC fails to bootstrap with MALLOC_PERTURB – Segfault in bitmap_obstack_free

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54313

             Bug #: 54313
           Summary: [4.8 Regression] GCC fails to bootstrap with
                    MALLOC_PERTURB – Segfault in bitmap_obstack_free
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: build, ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
                CC: steven@gcc.gnu.org


If malloc doesn't return nullified memory, bootstrapping fails as soon as the
stage1 compiler is used to build libgcc.


To reproduce: With GLIBC, simply set
  export MALLOC_PERTURB_=163
and on FreeBSD, use jemalloc with junk filling.


Then either bootstrap, which will fail at the first use of the stage1 compiler,
i.e. when building the first libgcc file.


Or if you already have a bootstrapped compiler:

$ cat test.c
int main () {
  return 0;
}
$ gcc -c -O test.c 
test.c: In function 'main':
test.c:3:1: internal compiler error: Segmentation fault
 }
 ^
Please submit a full bug report,


That fails in:
$ gdb --args ~/projects/gcc-git/gcc-build/gcc/cc1 -O test.c
...

Program received signal SIGSEGV, Segmentation fault.
0x0000000000600f52 in bitmap_obstack_free (map=0x157e5d0) at
/projects/tob/gcc-git/gcc/gcc/bitmap.c:388
388           map->first = (bitmap_element *) map->obstack->heads;

(gdb) p map->obstack
$1 = (bitmap_obstack *) 0xa3a3a3a3a3a3a3a3

(gdb) bt
#0  0x0000000000600f52 in bitmap_obstack_free (map=0x157e5d0) at
/projects/tob/gcc-git/gcc/gcc/bitmap.c:388
#1  0x0000000000ce5f46 in dse_step7 () at
/projects/tob/gcc-git/gcc/gcc/dse.c:3826
#2  rest_of_handle_dse () at /projects/tob/gcc-git/gcc/gcc/dse.c:3891
#3  0x0000000000868fef in execute_one_pass (pass=pass@entry=0x14483a0
<pass_rtl_dse1>) at /projects/tob/gcc-git/gcc/gcc/passes.c:2157
#4  0x00000000008693a5 in execute_pass_list (pass=0x14483a0 <pass_rtl_dse1>) at
/projects/tob/gcc-git/gcc/gcc/passes.c:2212
#5  0x00000000008693b7 in execute_pass_list (pass=0x1443220
<pass_rest_of_compilation>) at /projects/tob/gcc-git/gcc/gcc/passes.c:2213
#6  0x0000000000669b38 in expand_function (node=0x2aaaac192750) at
/projects/tob/gcc-git/gcc/gcc/cgraphunit.c:1609
#7  0x000000000066b9da in expand_all_functions () at
/projects/tob/gcc-git/gcc/gcc/cgraphunit.c:1714
#8  compile () at /projects/tob/gcc-git/gcc/gcc/cgraphunit.c:2012
#9  0x000000000066bfd5 in finalize_compilation_unit () at
/projects/tob/gcc-git/gcc/gcc/cgraphunit.c:2089
#10 0x0000000000560390 in c_write_global_declarations () at
/projects/tob/gcc-git/gcc/gcc/c/c-decl.c:10116
#11 0x000000000090a165 in compile_file () at
/projects/tob/gcc-git/gcc/gcc/toplev.c:560
#12 0x000000000090bcda in do_compile () at
/projects/tob/gcc-git/gcc/gcc/toplev.c:1863

[Bug middle-end/54313] [4.8 Regression] GCC fails to bootstrap with MALLOC_PERTURB – Segfault in bitmap_obstack_free

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54313

Steven Bosscher <steven at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch
             Status|UNCONFIRMED                 |NEW
                URL|                            |http://gcc.gnu.org/ml/gcc-p
                   |                            |atches/2012-08/msg01240.htm
                   |                            |l
   Last reconfirmed|                            |2012-08-18
     Ever Confirmed|0                           |1

--- Comment #1 from Steven Bosscher <steven at gcc dot gnu.org> 2012-08-18 10:31:44 UTC ---
One of the bitmap is BITMAP_FREE'd when its obstack is already released.

[Bug middle-end/54313] [4.8 Regression] GCC fails to bootstrap with MALLOC_PERTURB – Segfault in bitmap_obstack_free

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54313

--- Comment #2 from Steven Bosscher <steven at gcc dot gnu.org> 2012-08-18 10:35:41 UTC ---
Author: steven
Date: Sat Aug 18 10:35:36 2012
New Revision: 190502

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190502
Log:
    PR middle-end/54313
    * dse.c (dse_step7): Don't free kill_on_calls bitmap, it is
    freed when its obstack is release.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dse.c

[Bug middle-end/54313] [4.8 Regression] GCC fails to bootstrap with MALLOC_PERTURB – Segfault in bitmap_obstack_free

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54313

Steven Bosscher <steven at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

--- Comment #3 from Steven Bosscher <steven at gcc dot gnu.org> 2012-08-18 10:36:20 UTC ---
.

[Bug middle-end/54313] [4.8 Regression] GCC fails to bootstrap with MALLOC_PERTURB – Segfault in bitmap_obstack_free

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54313

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.0