[Bug c/28621] New: SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[Bug c/28621] New: SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[magsilva at gmail dot com]

After build a new version of procps using the "-Os" flag for gcc, all its
(procps) software (ps, top, etc) were failing due to a segmentation fault. I
couldn't find a report about that at Bugzilla, but I did find one at
"http://www.netdomination.org/~stkn/index.php?/archives/24-Anatomy-of-a-segfault....html".
Although the author of that report was using ulibc (and I glibc), it applied
perfectly to my case. After I removed the "-ffast-math" from the procps compile
command, everything worked fine again.


-- 
           Summary: SEGSEGV at set_fast_math () at
                    ../../gcc/config/i386/crtfastmath.c:97 when using the -
                    Os flag
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: magsilva at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |target
            Summary|SEGSEGV at set_fast_math () |[4.1/4.2 Regression] SEGSEGV
                   |at                          |at set_fast_math () at
                   |../../gcc/config/i386/crtfas|../../gcc/config/i386/crtfas
                   |tmath.c:97 when using the - |tmath.c:97 when using the -
                   |Os flag                     |Os flag
   Target Milestone|---                         |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2006-08-06 17:19 -------
http://gcc.gnu.org/ml/gcc-patches/2006-03/msg01179.html


Caused by the patch at:
http://gcc.gnu.org/ml/gcc/2005-08/msg00281.html


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl at gcc dot gnu dot org
           Severity|normal                      |blocker
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-08-06 17:19:06
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[hjl at lucon dot org]

------- Comment #2 from hjl at lucon dot org  2006-08-06 18:29 -------
The main problem is bug 27537. That is -Os aligns stack at 4 bytes and the
other
part of i386 backend assumes stack aliged at 16byte. We can word around this by

1. Don't include crtfastmath.o for -m32.
2. Make crtfastmath.o dummy for -m32.
3. Use a static variable to align at 16byte.
4. Compile crtfastmath.o with -mstackrealign. Need to backport -mstackrealign
to
4.1?
5. Fix i386 backend only to assume 4byte stack alignment.

The easiest one is #2 or #3. The idel one is #5.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[hubicka at gcc dot gnu dot org]

------- Comment #3 from hubicka at gcc dot gnu dot org  2006-08-07 10:18 -------
Hi,
because of quite serve register pressure issues, I don't like much idea of GCC
realocating stack transparently (it is also dificult to teach reload to decide
when alignment is needed).  Safe bugfix for 4.2 seems to be this:
        PR target/28621
        * crtfastmath.c (force_align_arg_pointer): Force stack alignment.
Index: config/i386/crtfastmath.c
===================================================================
-u -L config/i386/crtfastmath.c (revision 115987) -L config/i386/crtfastmath.c 
(working copy) config/i386/.svn/text-base/crtfastmath.c.svn-base
config/i386/crtfastmath.c
--- config/i386/crtfastmath.c   (revision 115987)
+++ config/i386/crtfastmath.c   (working copy)
@@ -38,6 +38,9 @@
 #define SSE    (1 << 25)

 static void __attribute__((constructor))
+#ifndef __x86_64__
+__attribute__ ((force_align_arg_pointer))
+#endif
 set_fast_math (void)
 {
 #ifndef __x86_64__

Does it help?
Honza


-- 

hubicka at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SEGSEGV at set_fast_math () at ../../gcc/config/i386/crtfastmath.c:97 when using the -Os flag

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
   Last reconfirmed|2006-08-06 17:19:06         |2006-08-08 00:29:48
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SIGSEGV in set_fast_math () at -Os

[magsilva at gmail dot com]

------- Comment #4 from magsilva at gmail dot com  2006-08-11 13:27 -------
(In reply to comment #3)
> --- config/i386/crtfastmath.c   (revision 115987)
> +++ config/i386/crtfastmath.c   (working copy)
> @@ -38,6 +38,9 @@
>  #define SSE    (1 << 25)
> 
>  static void __attribute__((constructor))
> +#ifndef __x86_64__
> +__attribute__ ((force_align_arg_pointer))
> +#endif
>  set_fast_math (void)
>  {
>  #ifndef __x86_64__
> 
> Does it help?

I applied this patch against the gcc 4.1.1, but the bug is still there (at
least procps keeps segfaulting).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SIGSEGV in set_fast_math () at -Os

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2006-08-18 04:34 -------
(In reply to comment #4)
> I applied this patch against the gcc 4.1.1, but the bug is still there (at
> least procps keeps segfaulting).

4.1.1 did not have the force_align_arg_pointer attribute so what do you expect.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SIGSEGV in set_fast_math () at -Os

[magsilva at gmail dot com]

------- Comment #6 from magsilva at gmail dot com  2006-08-18 07:16 -------
Sorry, but I didn't know that. I reported the bug against GCC 4.1.1 and the
target milestone set for it is GCC 4.1.2. So, I expected that patch to work
with gcc 4.1.x. The 'force_align_arg_pointer' attribute is available at GCC
4.1.2 or just GCC 4.2.x?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SIGSEGV in set_fast_math () at -Os

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2006-08-18 11:42 -------
(In reply to comment #6)
> Sorry, but I didn't know that. I reported the bug against GCC 4.1.1 and the
> target milestone set for it is GCC 4.1.2. So, I expected that patch to work
> with gcc 4.1.x. The 'force_align_arg_pointer' attribute is available at GCC
> 4.1.2 or just GCC 4.2.x?

Just 4.2.0 which right now the trunk (aka mainline) of the svn.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SIGSEGV in set_fast_math () at -Os

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1/4.2 Regression] SIGSEGV in set_fast_math () at -Os

[pbrook at gcc dot gnu dot org]

------- Comment #8 from pbrook at gcc dot gnu dot org  2006-08-25 20:40 -------
Subject: Bug 28621

Author: pbrook
Date: Fri Aug 25 20:39:48 2006
New Revision: 116431

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=116431
Log:
2006-08-25  Jan Hubicka  <jh@suse.cz>

        PR target/28621
        * config/i386/crtfastmath.c (set_fast_math): Force stack alignment.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/crtfastmath.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1 Regression] SIGSEGV in set_fast_math () at -Os

[hjl at lucon dot org]

------- Comment #9 from hjl at lucon dot org  2006-09-08 00:51 -------
Fix for PR 13685 should also fix this bug. In fact, we can back out the
change in comment #3.


-- 

hjl at lucon dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|27537                       |13685


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1 Regression] SIGSEGV in set_fast_math () at -Os

[hjl at lucon dot org]

------- Comment #10 from hjl at lucon dot org  2006-09-08 00:52 -------
We can even back out the patch and close it as a dup for PR 13685.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1 Regression] SIGSEGV in set_fast_math () at -Os

[pinskia at gcc dot gnu dot org]

------- Comment #11 from pinskia at gcc dot gnu dot org  2006-09-08 01:18 -------
(In reply to comment #10)
> We can even back out the patch and close it as a dup for PR 13685.
Not really and here is why:
-Os on the file containing main will still crash.  -Os -msse on the file with
main will not crash.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1 Regression] SIGSEGV in set_fast_math () at -Os

[hjl at gcc dot gnu dot org]

------- Comment #12 from hjl at gcc dot gnu dot org  2006-09-11 21:34 -------
Subject: Bug 28621

Author: hjl
Date: Mon Sep 11 21:34:06 2006
New Revision: 116860

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=116860
Log:
gcc/

2006-09-11  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/13685
        PR target/27537
        PR target/28621
        * config/i386/i386.c (override_options): Always default to 16
        byte stack boundary.

gcc/testsuite/

2006-09-11  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/13685
        * gcc.target/i386/pr13685.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr13685.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1 Regression] SIGSEGV in set_fast_math () at -Os

[hjl at gcc dot gnu dot org]

------- Comment #13 from hjl at gcc dot gnu dot org  2006-09-12 02:54 -------
Subject: Bug 28621

Author: hjl
Date: Tue Sep 12 02:54:42 2006
New Revision: 116870

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=116870
Log:
gcc/

2006-09-11  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/13685
        PR target/27537
        PR target/28621
        * config/i386/i386.c (override_options): Always default to 16
        byte stack boundary.

gcc/testsuite/

2006-09-11  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/13685
        * gcc.target/i386/pr13685.c: New test.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.target/i386/pr13685.c
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/config/i386/i386.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621

[Bug target/28621] [4.1 Regression] SIGSEGV in set_fast_math () at -Os

[hjl at lucon dot org]

------- Comment #14 from hjl at lucon dot org  2006-09-12 05:34 -------
Fixed.


-- 

hjl at lucon dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to fail|4.1.2                       |
      Known to work|4.2.0 4.0.0                 |4.2.0 4.1.2 4.0.0
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28621