cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

[Alexandre Oliva]

Hi there!

I've been unable to bootstrap the latest snapshots of gcc and egcs on
sparc-sun-sunos4.1.3, configured --with-gnu-as --enable-shared, using
GNU as and GNU ld from binutils 2.8.1 as assembler and linker, with
BOOT_CFLAGS="-O4 -g", using egcs-1.0 as the stage1 compiler.  I don't
know whether this is a bug in egcs-1.0 or in the current snapshots of
both packages.  The error I get is exactly the same for both builds:

stage1/xgcc -Bstage1/  -DIN_GCC    -O4 -g  -DHAVE_CONFIG_H  -o genattr \
 genattr.o rtl.o ` case "obstack.o" in ?*) echo obstack.o ;; esac ` ` case "stage1/xgcc -Bstage1/"@"" in "cc"@?*) echo  ;; esac ` ` case "" in ?*) echo  ;; esac `
./genattr /n/temp1/gcctest/bin/../src/ss/gcc/config/sparc/sparc.md > tmp-attr.h
/bin/sh: 9857 Memory fault - core dumped
make[2]: *** [stamp-attr] Error 139
make[2]: Leaving directory `/tmp_mnt/n/temp1/tmp/gcctest/src/atibaia/ss/gcc'
make[1]: *** [bootstrap] Error 2
make[1]: Leaving directory `/tmp_mnt/n/temp1/tmp/gcctest/src/atibaia/ss/gcc'
make: *** [bootstrap] Error 2

genattr crashes in the initialization code, with a stack trace like
this (I removed the buggy program before I decided to post this
message, so I quote from memory):

??? (invalid address)
memcpy
__main
main

-- 
Alexandre Oliva
mailto:oliva@dcc.unicamp.br mailto:aoliva@acm.org
http://www.dcc.unicamp.br/~oliva
Universidade Estadual de Campinas, SP, Brasil

Re: cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

[Manfred.Hollstein]

On , 10 December 1997, 16:17:27, oliva@dcc.unicamp.br wrote:

 > Hi there!
 > 
 > I've been unable to bootstrap the latest snapshots of gcc and egcs on
 > sparc-sun-sunos4.1.3, configured --with-gnu-as --enable-shared, using
 > GNU as and GNU ld from binutils 2.8.1 as assembler and linker, with
 > BOOT_CFLAGS="-O4 -g", using egcs-1.0 as the stage1 compiler.  I don't
 > know whether this is a bug in egcs-1.0 or in the current snapshots of
 > both packages.  The error I get is exactly the same for both builds:
 > 
 > stage1/xgcc -Bstage1/  -DIN_GCC    -O4 -g  -DHAVE_CONFIG_H  -o genattr \
 >  genattr.o rtl.o ` case "obstack.o" in ?*) echo obstack.o ;; esac ` ` case "stage1/xgcc -Bstage1/"@"" in "cc"@?*) echo  ;; esac ` ` case "" in ?*) echo  ;; esac `
 > ./genattr /n/temp1/gcctest/bin/../src/ss/gcc/config/sparc/sparc.md > tmp-attr.h
 > /bin/sh: 9857 Memory fault - core dumped
 > make[2]: *** [stamp-attr] Error 139
 > make[2]: Leaving directory `/tmp_mnt/n/temp1/tmp/gcctest/src/atibaia/ss/gcc'
 > make[1]: *** [bootstrap] Error 2
 > make[1]: Leaving directory `/tmp_mnt/n/temp1/tmp/gcctest/src/atibaia/ss/gcc'
 > make: *** [bootstrap] Error 2
 > 
 > genattr crashes in the initialization code, with a stack trace like
 > this (I removed the buggy program before I decided to post this
 > message, so I quote from memory):
 > 
 > ??? (invalid address)
 > memcpy
 > __main
 > main
 > 

Same here:

$ gdb genattr core 
Core was generated by `genattr'.
Program terminated with signal 11, Segmentation fault.
#0  0xef7f1d08 in ?? ()
Breakpoint 1 at 0x8130
(gdb) bt
#0  0xef7f1d08 in ?? ()
#1  0xef7f1c28 in ?? ()
#2  0xef7f0084 in ?? ()
#3  0x8180 in memset ()
#4  0x6368 in __do_global_ctors ()
#5  0x6390 in __main ()
#6  0x309c in main ()

Also interesting, cpp built by the stage1 compiler:

$ ./cpp -v -dM
ld.so: unidentifiable procedure reference at 0x1e2a4

Looks like gcc/egcs on SunOS are seriously broken!

Manfred

Re: cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

[Manfred.Hollstein]

On Thu, 11 December 1997, 01:30:37, eggert@twinsun.com wrote:

 >    Date: Thu, 11 Dec 97 08:07:31 +0100
 >    From: Manfred.Hollstein@ks.sel.alcatel.de
 > 
 >    Looks like gcc/egcs on SunOS are seriously broken!
 > 
 > I don't think it's a problem with SunOS in general.  I'm not observing
 > the bug on my sparc-sun-sunos4.1.4 build with gcc 2.8 1997-12-10.  I'm
 > using SunOS 4.1.4 with all patches recommended by Sun, and compiling
 > with -O; I tried -O4 and could still build stamp-attr without problem.
 > 
 > The problem could be specific to SunOS 4.1.3; or it could be a Sun bug
 > fixed by one of the Sun patches I've installed; or it could be
 > something else.
 > 
 > Here's how to find out which patches Sun recommends for SunOS 4.1.x.
 > 
 > for SunOS:	see:
 > 4.1.3		ftp://sunsolve.sun.com/pub/patches/Solaris1.1.PatchReport
 > 4.1.3_U1	ftp://sunsolve.sun.com/pub/patches/Solaris1.1.1.PatchReport
 > 4.1.4		ftp://sunsolve.sun.com/pub/patches/Solaris1.1.2.PatchReport

Thanks for the info; I'll have to talk to our local IT about that.

But, the problem did occur only with the latest egcs-971207 snapshot;
up to egcs-971201 and egcs-1.0 everything was OK, even with -O9!

Re: cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

[Paul Eggert]

   Date: Thu, 11 Dec 97 08:07:31 +0100
   From: Manfred.Hollstein@ks.sel.alcatel.de

   Looks like gcc/egcs on SunOS are seriously broken!

I don't think it's a problem with SunOS in general.  I'm not observing
the bug on my sparc-sun-sunos4.1.4 build with gcc 2.8 1997-12-10.  I'm
using SunOS 4.1.4 with all patches recommended by Sun, and compiling
with -O; I tried -O4 and could still build stamp-attr without problem.

The problem could be specific to SunOS 4.1.3; or it could be a Sun bug
fixed by one of the Sun patches I've installed; or it could be
something else.

Here's how to find out which patches Sun recommends for SunOS 4.1.x.

for SunOS:	see:
4.1.3		ftp://sunsolve.sun.com/pub/patches/Solaris1.1.PatchReport
4.1.3_U1	ftp://sunsolve.sun.com/pub/patches/Solaris1.1.1.PatchReport
4.1.4		ftp://sunsolve.sun.com/pub/patches/Solaris1.1.2.PatchReport

Re: cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

[Jeffrey A Law]

  In message < 9712110707.AA07283@lts.sel.alcatel.de >you write:
  > Same here:
  > 
  > $ gdb genattr core 
  > Core was generated by `genattr'.
  > Program terminated with signal 11, Segmentation fault.
  > #0  0xef7f1d08 in ?? ()
  > Breakpoint 1 at 0x8130
  > (gdb) bt
  > #0  0xef7f1d08 in ?? ()
  > #1  0xef7f1c28 in ?? ()
  > #2  0xef7f0084 in ?? ()
  > #3  0x8180 in memset ()
  > #4  0x6368 in __do_global_ctors ()
  > #5  0x6390 in __main ()
  > #6  0x309c in main ()
  > 
  > Also interesting, cpp built by the stage1 compiler:
  > 
  > $ ./cpp -v -dM
  > ld.so: unidentifiable procedure reference at 0x1e2a4
  > 
  > Looks like gcc/egcs on SunOS are seriously broken!
Are we still having this problem?

jeff

Re: cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3

[Alexandre Oliva]

Jeffrey A Law writes:

> Are we still having this problem?

No, I was able to bootstrap the latest snapshots of both gcc-2.8.0 and
egcs on SunOS 4.1.3, with exactly the same configuration that had
previously failed.

-- 
Alexandre Oliva
mailto:oliva@dcc.unicamp.br mailto:aoliva@acm.org
http://www.dcc.unicamp.br/~oliva
Universidade Estadual de Campinas, SP, Brasil

New problems with gcc-2.8.0 based code [was: Re: cannot bootstrap neither gcc-2.8.0-971206 nor egcs-971207 on sparc-sun-sunos4.1.3 ]

[Manfred Hollstein]

On Mon, 22 December 1997, 13:09:14, law@cygnus.com wrote:

 > 
 >   In message < 9712110707.AA07283@lts.sel.alcatel.de >you write:
 >   > Same here:
 >   > 
 >   > $ gdb genattr core 
 >   > Core was generated by `genattr'.
 >   > Program terminated with signal 11, Segmentation fault.
 >   > #0  0xef7f1d08 in ?? ()
 >   > Breakpoint 1 at 0x8130
 >   > (gdb) bt
 >   > #0  0xef7f1d08 in ?? ()
 >   > #1  0xef7f1c28 in ?? ()
 >   > #2  0xef7f0084 in ?? ()
 >   > #3  0x8180 in memset ()
 >   > #4  0x6368 in __do_global_ctors ()
 >   > #5  0x6390 in __main ()
 >   > #6  0x309c in main ()
 >   > 
 >   > Also interesting, cpp built by the stage1 compiler:
 >   > 
 >   > $ ./cpp -v -dM
 >   > ld.so: unidentifiable procedure reference at 0x1e2a4
 >   > 
 >   > Looks like gcc/egcs on SunOS are seriously broken!
 > Are we still having this problem?
 > 
 > jeff

Sorry, I  can't say, as I currently  don't have access to the machines
at work.  But, as Alexandre already pointed out, this problem seems to
have been gone.

There are other problems since the merge with gcc-2.8.0, though.

Up to egcs-1.0  (incl. egcs-971201) I've  been able to  built my Linux
kernel  with  `-O6 -march=pentium  -mcpu=pentium  -fomit-frame-pointer
-malign-loops=0      -malign-jumps=0      -malign-functions=0'   _and_
`-funroll-all-loops'!

Newer   snapshots and  gcc-2.8.0-971213 don't  allow  me   to do that;
`-funroll-all-loops' causes   `isapnp'  and  `clock'  to   fail   with
`segmentation  violations'.  Omitting   `-funroll-all-loops' helps for
the most current 2.1.7x kernels, but 2.0.33 still fails if compiled by
gcc-2.8.0 and egcs-971215!

Did anybody else see similar symptoms?

Looks - at least  for me - like  the loop unrolling stuff (and perhaps
other as well) hasn't really been improved by the merge with gcc-2.8.0
:-(

Manfred

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Manfred Hollstein]

On Fri, 26 December 1997, 15:11:14, manfred@s-direktnet.de wrote:

 > There are other problems since the merge with gcc-2.8.0, though.
 > 
 > Up to egcs-1.0  (incl. egcs-971201) I've  been able to  built my Linux
 > kernel  with  `-O6 -march=pentium  -mcpu=pentium  -fomit-frame-pointer
 > -malign-loops=0      -malign-jumps=0      -malign-functions=0'   _and_
 > `-funroll-all-loops'!
 > 
 > Newer   snapshots and  gcc-2.8.0-971213 don't  allow  me   to do that;
 > `-funroll-all-loops' causes   `isapnp'  and  `clock'  to   fail   with
 > `segmentation  violations'.  Omitting   `-funroll-all-loops' helps for
 > the most current 2.1.7x kernels, but 2.0.33 still fails if compiled by
 > gcc-2.8.0 and egcs-971215!
 > 
 > Did anybody else see similar symptoms?
 > 
 > Looks - at least  for me - like  the loop unrolling stuff (and perhaps
 > other as well) hasn't really been improved by the merge with gcc-2.8.0
 > :-(

Just compiled my 2.1.76 kernel once  again this time using egcs-971225
to see if the `-funroll-all-loops' still persists.

IT'S FIXED!

I writing this e-mail  on the freshly compiled  kernel and didn't  had
any problems so far.  I'll only have  to reboot later  on to sent this
mail out into  the world, as  ISDN is still broken  in the most recent
kernels :-(

Keep up the good work, cheers 1998

Manfred

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Richard Stallman]

    Just compiled my 2.1.76 kernel once  again this time using egcs-971225
    to see if the `-funroll-all-loops' still persists.

    IT'S FIXED!

Is it fixed in the latest GCC snapshot?  If not, the job isn't done
yet.  Can someone identify what change deals with this, and get it
installed in GCC?

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Jeffrey A Law]

  In message < 199712290718.AAA13426@wijiji.santafe.edu >you write:
  >     Just compiled my 2.1.76 kernel once  again this time using egcs-971225
  >     to see if the `-funroll-all-loops' still persists.
  > 
  >     IT'S FIXED!
  > 
  > Is it fixed in the latest GCC snapshot?  If not, the job isn't done
  > yet.  Can someone identify what change deals with this, and get it
  > installed in GCC?
Manfred -- What was the failure mode?  Mis-compiled code, compiler
abort, etc?

The only unrolling bug we've fixed recently was a problem with
find_splittable_givs trying to split givs with a dest_reg that was
created by loop.
(which could cause either a segfault in unroll, or incorrect code).

We fixed this in egcs back in late Nov.  I can forward that fix to
gcc2 if the maintainers want to look at it.

jeff

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Jeffrey A Law]

  In message < 199712291737.SAA07160@saturn.s-direktnet.de >you write:
  > Well, it wasn't a failure of the compiler! The kernel and all the modules
  > could be built successfully, but when booting this kernel some system
  > calls issued by the two programs `isapnp' and `clock' reproducably fail,
  > i.e. cause `segmentation violations' of the two programs.
OK.  That points to either a code generation bug or a bug in the linux
source.

  > I then recompiled isapnp and clock with gcc-2.8.0 and now the situation
  > became even worse: no more SIGSEGV's but kernel oops's!
:(


  > Perhaps I should look at the source of the particular programs and find
  > out using strace what's really going on.
Might be helpful.  Though I suspect it's a kernel module that's being
mis-compiled or is incorrectly written, so the strace might tell us
what syscall is failing.

jeff

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Manfred Hollstein]

On Mon, 29 December 1997, 00:18:31, rms@santafe.edu wrote:

 >     Just compiled my 2.1.76 kernel once  again this time using egcs-971225
 >     to see if the `-funroll-all-loops' still persists.
 > 
 >     IT'S FIXED!
 > 
 > Is it fixed in the latest GCC snapshot?  If not, the job isn't done
 > yet.  Can someone identify what change deals with this, and get it
 > installed in GCC?
 > 

I just tried the latest gcc2 snapshot (971225), and it's not fixed. Only
egcs-971225 works correctly. I have no idea though, whether it's actually
a gcc or a Linux bug (the fact that linux-2.1.76 works ok with
`-funroll-all-loops' while 2.0.33 doesn't indicates perhaps that Linux is
to blame).

Manfred

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Manfred Hollstein]

On Mon, 29 December 1997, 08:46:13, law@hurl.cygnus.com wrote:

 > 
 >   In message < 199712290718.AAA13426@wijiji.santafe.edu >you write:
 >   >     Just compiled my 2.1.76 kernel once  again this time using egcs-971225
 >   >     to see if the `-funroll-all-loops' still persists.
 >   > 
 >   >     IT'S FIXED!
 >   > 
 >   > Is it fixed in the latest GCC snapshot?  If not, the job isn't done
 >   > yet.  Can someone identify what change deals with this, and get it
 >   > installed in GCC?
 > Manfred -- What was the failure mode?  Mis-compiled code, compiler
 > abort, etc?
 > 
 > The only unrolling bug we've fixed recently was a problem with
 > find_splittable_givs trying to split givs with a dest_reg that was
 > created by loop.
 > (which could cause either a segfault in unroll, or incorrect code).
 > 
 > We fixed this in egcs back in late Nov.  I can forward that fix to
 > gcc2 if the maintainers want to look at it.
 > 

Well, it wasn't a failure of the compiler! The kernel and all the modules
could be built successfully, but when booting this kernel some system
calls issued by the two programs `isapnp' and `clock' reproducably fail,
i.e. cause `segmentation violations' of the two programs.

I then recompiled isapnp and clock with gcc-2.8.0 and now the situation
became even worse: no more SIGSEGV's but kernel oops's!

Perhaps I should look at the source of the particular programs and find
out using strace what's really going on.

Manfred

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Manfred Hollstein]

On Mon, 29 December 1997, 11:16:37, law@hurl.cygnus.com wrote:

 >   In message < 199712291737.SAA07160@saturn.s-direktnet.de >you write:
 >   > Well, it wasn't a failure of the compiler! The kernel and all the modules
 >   > could be built successfully, but when booting this kernel some system
 >   > calls issued by the two programs `isapnp' and `clock' reproducably fail,
 >   > i.e. cause `segmentation violations' of the two programs.
 > OK.  That points to either a code generation bug or a bug in the linux
 > source.
 > 
 >   > I then recompiled isapnp and clock with gcc-2.8.0 and now the situation
 >   > became even worse: no more SIGSEGV's but kernel oops's!
 > :(
 > 
 > 
 >   > Perhaps I should look at the source of the particular programs and find
 >   > out using strace what's really going on.
 > Might be helpful.  Though I suspect it's a kernel module that's being
 > mis-compiled or is incorrectly written, so the strace might tell us
 > what syscall is failing.
 > 
 > jeff
 > 

I'm very sorry  for bothering you  with my kernel logs  :-( But as the
replies from RMS and likewise important GNU people indicate, it really
looks  as if we   reached a  situation  where  something needs to   be
clarified between the Linux and the GNU/gcc folks.

I just compiled Linux-2.1.76 twice:

  1. Using egcs-971225
  2. Using gcc-2.8.0-971225

Both compilations used the following flags and finished successfully:

  -march=pentium -mcpu=pentium -malign-loops=0 -malign-jumps=0 \
  -malign-functions=0 -DCPU=586 -fomit-frame-pointer -funroll-all-loops

Booting kernel 1. results in the following (from /var/log/kern.log):

  Dec 30 14:10:51 saturn kernel: klogd 1.3-3, log source = /proc/kmsg started.
  Dec 30 14:10:51 saturn kernel: Loaded 4218 symbols from /System.map.
  Dec 30 14:10:51 saturn kernel: Symbols match kernel version 2.1.76.
  Dec 30 14:10:51 saturn kernel: Error seeking in /dev/kmem 
  Dec 30 14:10:51 saturn kernel: Error adding kernel module table entry. 
  Dec 30 14:10:51 saturn kernel: Linux version 2.1.76 (manfred@saturn) (gcc version egcs-2.91.03 971225 (gcc-2.8.0)) #1 Sun Dec 28 12:20:54 MET 1997 
  Dec 30 14:10:51 saturn kernel: Console: 15 point font, 600 scans 
  Dec 30 14:10:51 saturn kernel: Console: colour VGA+ 100x40, 1 virtual console (max 63) 
  Dec 30 14:10:51 saturn kernel: PCI: BIOS32 Service Directory structure at 0xc00f99e0 
  Dec 30 14:10:51 saturn kernel: PCI: BIOS32 Service Directory entry at 0xf0400 
  Dec 30 14:10:51 saturn kernel: PCI: PCI BIOS revision 2.10 entry at 0xf0430 
  Dec 30 14:10:51 saturn kernel: Probing PCI hardware. 
  Dec 30 14:10:51 saturn kernel: Calibrating delay loop... 79.87 BogoMIPS 
  Dec 30 14:10:51 saturn kernel: Memory: 63132k/65536k available (952k kernel code, 392k reserved, 1028k data, 32k init) 
  Dec 30 14:10:51 saturn kernel: Swansea University Computer Society NET3.039 for Linux 2.1 
  Dec 30 14:10:51 saturn kernel: NET3: Unix domain sockets 0.16 for Linux NET3.038. 
  Dec 30 14:10:51 saturn kernel: Swansea University Computer Society TCP/IP for NET3.037 
  Dec 30 14:10:51 saturn kernel: IP Protocols: ICMP, UDP, TCP 
  Dec 30 14:10:51 saturn kernel: CPU: Intel Pentium 75+ stepping 0c 
  Dec 30 14:10:51 saturn kernel: Checking 386/387 coupling... Ok, fpu using exception 16 error reporting. 
  Dec 30 14:10:51 saturn kernel: Checking 'hlt' instruction... Ok. 
  Dec 30 14:10:51 saturn kernel: Intel Pentium with F0 0F bug - workaround enabled. 
  Dec 30 14:10:51 saturn kernel: POSIX conformance testing by UNIFIX 
  Dec 30 14:10:51 saturn kernel: Starting kswapd v 1.23  
  Dec 30 14:10:51 saturn kernel: Serial driver version 4.24 with no serial options enabled 
  Dec 30 14:10:51 saturn kernel: ttyS00 at 0x03f8 (irq = 4) is a 16550A 
  Dec 30 14:10:51 saturn kernel: ttyS01 at 0x02f8 (irq = 3) is a 16550A 
  Dec 30 14:10:51 saturn kernel: Uniform CD-ROM driver revision 2.0 
  Dec 30 14:10:51 saturn kernel: aic7xxx: <Adaptec AHA-294X SCSI host adapter> at PCI 12 
  Dec 30 14:10:51 saturn kernel: aic7xxx: BIOS enabled, IO Port 0xd800, IO Mem 0xe3800000, IRQ 11, Revision B 
  Dec 30 14:10:51 saturn kernel: aic7xxx: Single Channel, SCSI ID 7, 16/255 SCBs, QFull 16, QMask 0x1f 
  Dec 30 14:10:51 saturn kernel: scsi0 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 4.1/3.2 
  Dec 30 14:10:51 saturn kernel: scsi : 1 host. 
  Dec 30 14:10:51 saturn kernel: scsi0: Scanning channel A for devices. 
  Dec 30 14:10:51 saturn kernel:   Vendor: IBM       Model: DORS-32160        Rev: S82C 
  Dec 30 14:10:51 saturn kernel:   Type:   Direct-Access                      ANSI SCSI revision: 02 
  Dec 30 14:10:51 saturn kernel: Detected scsi disk sda at scsi0, channel 0, id 0, lun 0 
  Dec 30 14:10:51 saturn kernel:   Vendor: IBM       Model: DORS-32160        Rev: WA0A 
  Dec 30 14:10:51 saturn kernel:   Type:   Direct-Access                      ANSI SCSI revision: 02 
  Dec 30 14:10:51 saturn kernel: Detected scsi disk sda at scsi0, channel 0, id 1, lun 0 
  Dec 30 14:10:51 saturn kernel:   Vendor: PIONEER   Model: CD-ROM DR-124X    Rev: 1.00 
  Dec 30 14:10:51 saturn kernel:   Type:   CD-ROM                             ANSI SCSI revision: 02 
  Dec 30 14:10:51 saturn kernel: scsi : detected 2 SCSI disks total. 
  Dec 30 14:10:51 saturn kernel: SCSI device sda: hdwr sector= 512 bytes. Sectors= 4226725 [2063 MB] [2.1 GB] 
  Dec 30 14:10:51 saturn kernel: SCSI device sda: hdwr sector= 512 bytes. Sectors= 4226725 [2063 MB] [2.1 GB] 
  Dec 30 14:10:51 saturn kernel: Partition check: 
  Dec 30 14:10:51 saturn kernel:  sda: sda1 sda2 sda3 < sda5 > 
  Dec 30 14:10:51 saturn kernel:  sdb: sdb1 < sdb5 sdb6 sdb7 sdb8 > 
  Dec 30 14:10:51 saturn kernel: VFS: Mounted root (ext2 filesystem) readonly. 
  Dec 30 14:10:51 saturn kernel: Freeing unused kernel memory: 32k freed 
  Dec 30 14:10:51 saturn kernel: Adding Swap: 130748k swap-space (priority -1) 
  Dec 30 14:10:51 saturn kernel: Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996 

and so on .. nothing really interesting happens.
BUT booting kernel 2. will work comparable only until the swap file is
added:

[Same messages deleted]
  Dec 30 13:58:50 saturn kernel: Freeing unused kernel memory: 32k freed 
  Dec 30 13:58:50 saturn kernel: Adding Swap: 130748k swap-space (priority -1) 
  Dec 30 13:58:50 saturn kernel: kmem_free: Either bad obj addr or double free (objp=c3e7b800, name=size-2048) 
  Dec 30 13:58:50 saturn kernel: kmem_free: Either bad obj addr or double free (objp=c3e7b000, name=size-2048) 
  Dec 30 13:58:50 saturn kernel: kmem_free: Either bad obj addr or double free (objp=c3e7a800, name=size-2048) 
  Dec 30 13:58:50 saturn kernel: kmem_free: Either bad obj addr or double free (objp=c3e7a000, name=size-2048) 
  Dec 30 13:58:50 saturn kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000018 
  Dec 30 13:58:50 saturn kernel: current->tss.cr3 = 00101000, ^_r3 = 00101000 
  Dec 30 13:58:50 saturn kernel: *pde = 00000000 
  Dec 30 13:58:50 saturn kernel: Oops: 0000 
  Dec 30 13:58:50 saturn kernel: CPU:    0 
  Dec 30 13:58:50 saturn kernel: EIP:    0010:[<c01275d9>] 
  Dec 30 13:58:50 saturn kernel: EFLAGS: 00010002 
  Dec 30 13:58:50 saturn kernel: eax: 00000100   ebx: c02f52c0   ecx: 00000000   edx: c0221000 
  Dec 30 13:58:50 saturn kernel: esi: c3e79800   edi: 00000202   ebp: c3e79800   esp: c3e25f88 
  Dec 30 13:58:50 saturn kernel: ds: 0018   es: 0018   ss: 0018 
  Dec 30 13:58:50 saturn kernel: Process modutils (pid: 25, process nr: 8, stackpage=c3e25000) 
  Dec 30 13:58:50 saturn kernel: Stack: c3e24000 c3e887c0 00000400 00000021 c011b96d c009cda0 c011b99d c3e79800  
  Dec 30 13:58:50 saturn kernel:        c3e24000 ffffffff fffffffc 00000000 c011c14c 00000000 c0109f1a 00000000  
  Dec 30 13:58:50 saturn kernel:        00000000 400d2c44 ffffffff fffffffc 00000000 00000001 0000002b 0000002b  
  Dec 30 13:58:50 saturn kernel: Call Trace: [<c011b96d>] [<c011b99d>] [<c011c14c>] [<c0109f1a>]  
  Dec 30 13:58:50 saturn kernel: Code: 2b 69 18 89 e8 31 d2 f7 73 08 8b 51 04 8d 14 82 89 54 24 10  
  Dec 30 13:58:50 saturn kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000018 
  Dec 30 13:58:50 saturn kernel: current->tss.cr3 = 00101000, ^_r3 = 00101000 
  Dec 30 13:58:50 saturn kernel: *pde = 00000000 
  Dec 30 13:58:50 saturn kernel: Oops: 0000 
  Dec 30 13:58:50 saturn kernel: CPU:    0 
  Dec 30 13:58:50 saturn kernel: EIP:    0010:[<c01275d9>] 
  Dec 30 13:58:50 saturn kernel: EFLAGS: 00010002 
  Dec 30 13:58:50 saturn kernel: eax: 00000100   ebx: c02f52c0   ecx: 00000000   edx: c0221000 
  Dec 30 13:58:50 saturn kernel: esi: c3e79000   edi: 00000202   ebp: c3e79000   esp: c3e1ff88 
  Dec 30 13:58:50 saturn kernel: ds: 0018   es: 0018   ss: 0018 
  Dec 30 13:58:50 saturn kernel: Process modutils (pid: 26, process nr: 9, stackpage=c3e1f000) 
  Dec 30 13:58:50 saturn kernel: Stack: c3e1e000 c3e898e0 00000400 00000021 c011b96d c009cfa0 c011b99d c3e79000  
  Dec 30 13:58:50 saturn kernel:        c3e1e000 ffffffff fffffffc 00000000 c011c14c 00000000 c0109f1a 00000000  
  Dec 30 13:58:50 saturn kernel:        00000000 400d2c44 ffffffff fffffffc 00000000 00000001 0000002b 0000002b  
  Dec 30 13:58:50 saturn kernel: Call Trace: [<c011b96d>] [<c011b99d>] [<c011c14c>] [<c0109f1a>]  
  Dec 30 13:58:50 saturn kernel: Code: 2b 69 18 89 e8 31 d2 f7 73 08 8b 51 04 8d 14 82 89 54 24 10  
  Dec 30 13:58:50 saturn kernel: kmem_free: Either bad obj addr or double free (objp=c3c57000, name=size-2048) 
  Dec 30 13:58:50 saturn kernel: kmem_free: Either bad obj addr or double free (objp=c3c56800, name=size-2048) 

And so on - a lot of kernel Oops's follow.  I really don't know, who's
to blame?!?!  Looking at Linux's `mm/slab.c' where the `kmem_free:..."
messages result from, doesn't really help, as there is _NO_ loop! BUT,
omitting `-funrool-all-loops' during compilation of the kernel results
in a working kernel without such messages?!?!

To summarize:

   - Kernel 2.1.76 built by egcs-971225 _and_ `-funroll-all-loops'
     works OK!
   - Kernel 2.1.76 built by egcs-971207 and -971215 and
     `-funroll-all-loops' DOESN'T work (for egcs-971207 we did
     the gcc-2.8.0 MERGE)!
   - Kernel 2.1.76 built by egcs-1.0 (and all previous snapshots!)
     and `-funroll-all-loops' works OK!
   - Kernel 2.1.76 built by gcc-2.8.0-971211, -971213 and -971225
     and `-funroll-all-loops' DOESN'T work!

Interestingly,    kernel    2.0.33    built   by  egcs-971225    _and_
`-funroll-all-loops' also doesn't work!

So, perhaps it's actually Linux or its  applications who's to blame?!?
Does  anybody know  an   e-mail address whom    we can  forward  these
questions?

Nevertheless, cheers 1998

Manfred

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Andi Kleen]

Manfred Hollstein <manfred@s-direktnet.de> writes:
> 
> To summarize:
> 
>    - Kernel 2.1.76 built by egcs-971225 _and_ `-funroll-all-loops'
>      works OK!
>    - Kernel 2.1.76 built by egcs-971207 and -971215 and
>      `-funroll-all-loops' DOESN'T work (for egcs-971207 we did
>      the gcc-2.8.0 MERGE)!
>    - Kernel 2.1.76 built by egcs-1.0 (and all previous snapshots!)
>      and `-funroll-all-loops' works OK!
>    - Kernel 2.1.76 built by gcc-2.8.0-971211, -971213 and -971225
>      and `-funroll-all-loops' DOESN'T work!

I remember a bugfix between egcs 1.0 and 1.0.1 so that it treats 
__asm__ statements without output operands always as volatile. The Linux
kernel depends on this behaviour. If gcc 2.8.0 doesn't have this bugfix
it could be the cause for your problems.

-Andi

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Philip Blundell]

>  Dec 30 13:58:50 saturn kernel: Call Trace: [<c011b96d>] [<c011b99d>] [<c011c
>14c>] [<c0109f1a>]  

Can you run this through the ksymoops decoder to get a meaningful backtrace 
(with function names)?

>And so on - a lot of kernel Oops's follow.  I really don't know, who's
>to blame?!?!  Looking at Linux's `mm/slab.c' where the `kmem_free:..."
>messages result from, doesn't really help, as there is _NO_ loop! BUT,

More likely it's the function that calls the SLAB code that is to blame.  If 
you find out what that is and compile it with -S -funroll-all-loops, that 
might be the way forward.

>Does  anybody know  an   e-mail address whom    we can  forward  these
>questions?

linux-kernel@vger.rutgers.edu is probably your best bet.

p.

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Paul Koning]

GCC 2.7.2.1 had a bug that showed up in some backends, and EGCS
exposed it with more backends, where asm statements that should have
been treated as unmovable were actually moved.  (Spefically, those
with no output arguments; the documentation quite rightly says that
those are always treated as if they were marked "volatile" even when
not so marked.)

That bug was fixed in egcs just a few weeks ago.  If gcc 2.8.x doesn't
have the corresponding fix, that could account for the problem.  As I
recall from the earlier discussion, one symptom of the bug was that
Linux would crash or otherwise misbehave, but only if you turned on
"enough" optimization.

The fix was only a few lines, you might try the experiment of applying
it to gcc 2.8 if the relevant module is reasonably similar.

	paul

Re: New problems with gcc-2.8.0 based code - NOW FIXED!

[Manfred Hollstein]

On , 30 December 1997, 18:50:24, ak@muc.de wrote:

 > I remember a bugfix between egcs 1.0 and 1.0.1 so that it treats 
 > __asm__ statements without output operands always as volatile. The Linux
 > kernel depends on this behaviour. If gcc 2.8.0 doesn't have this bugfix
 > it could be the cause for your problems.
 > 

After the  discussion  about __volatile__  __asm__ statements  I  just
added Jeffrey Law's patch to gcc-2.8.0-971225:

Mon Dec 15 08:48:24 1997  Jeffrey A Law  (law@cygnus.com)

	* stmt.c (expand_asm_operands): If an ASM has no outputs, then treat
	it as volatile.

diff --context --recursive --show-c-function -x *.o -x *.info* -x *.html* -x *.elc -x *.dvi -x *.orig -x *~ -x version.el gcc-2.8.0.orig/gcc/stmt.c gcc-2.8.0/gcc/stmt.c
*** gcc-2.8.0.orig/gcc/stmt.c	Tue Dec  9 01:07:38 1997
--- gcc-2.8.0/gcc/stmt.c	Wed Dec 31 23:42:54 1997
*************** expand_asm_operands (string, outputs, in
*** 1421,1426 ****
--- 1421,1430 ----
    /* The insn we have emitted.  */
    rtx insn;
  
+   /* An ASM with no outputs needs to be treated as volatile.  */
+   if (noutputs == 0)
+     vol = 1;
+ 
    if (output_bytecode)
      {
        error ("`asm' is invalid when generating bytecode");

rebuilt and installed the compiler. I then used this compiler to built
linux-2.1.76 once  again and I'm  still getting the same boot failures
(16 times the _same_ Oops's from boot to reboot):

 Unable to handle kernel NULL pointer dereference at virtual address 00000018 
 current->tss.cr3 = 00101000, ^_r3 = 00101000 
 *pde = 00000000 
 Oops: 0000 
 CPU:    0 
 EIP:    0010:[<kfree+12b/1cd>] 
 EFLAGS: 00010002 
 eax: 00000100   ebx: c02f52c0   ecx: 00000000   edx: c0221000 
 esi: c3e79800   edi: 00000202   ebp: c3e79800   esp: c3e25f88 
 ds: 0018   es: 0018   ss: 0018 
 Process modutils (pid: 25, process nr: 8, stackpage=c3e25000) 
 Stack: c3e24000 c3e887c0 00000400 00000021 c011b96d c009cda0 c011b99d c3e79800  
        c3e24000 ffffffff fffffffc 00000000 c011c14c 00000000 c0109f1a 00000000  
        00000000 400d2c44 ffffffff fffffffc 00000000 00000001 0000002b 0000002b  
 Call Trace: [<do_exit+1f7/29b>] [<do_exit+227/29b>] [<sys_waitpid>] [<system_call+3a/40>]
 Code: c01275d9 <kfree+12b/1cd>  2b 69 18       	subl   0x18(%ecx),%ebp
 Code: c01275dc <kfree+12e/1cd>  89 e8          	movl   %ebp,%eax
 Code: c01275de <kfree+130/1cd>  31 d2          	xorl   %edx,%edx
 Code: c01275e0 <kfree+132/1cd>  f7 73 08       	divl   0x8(%ebx),%eax
 Code: c01275e9 <kfree+13b/1cd>  8b 51 04       	movl   0x4(%ecx),%edx
 Code: c01275ec <kfree+13e/1cd>  8d 14 82       	leal   (%edx,%eax,4),%edx
 Code: c01275ef <kfree+141/1cd>  89 54 24 10    	movl   %edx,0x10(%esp,1)


Another   problem has been   shown   by  several  test programs   from
libg++-2.8.0b6.5.   As an   example,  try to    compile the  following
snippet:

/* File: t002.cc
 * Compiled by gcc-2.8.0-971225 using
 *		optimization
 *	  _and_ -funroll-all-loops
 *	  _and_	-g
 * results in an `Internal compiler error'.  */

#include <String.h>
#include <Regex.h>
#include <iostream.h>

int main (void)
{
	String z = "This string\thas\nfive words";
	String w[10];
	int nw = split (z, w, 10, RXwhite);

	for (int i = 0; i < nw; ++i)
	{
		cout << "z[" << i << "] = \"" << w[i] << "\"" << endl;
	}

	return 0;
}

$ gcc -v
Reading specs from /tools/gnu/lib/gcc-lib/i586-linux-gnulibc1/2.8.0/specs
gcc version 2.8.0
$ uname -a
Linux saturn 2.0.33 #7 Mon Dec 29 13:09:29 MET 1997 i586 unknown
$ gcc -O -funroll-all-loops -g -S t002.cc
t002.cc: In function `int main()':
t002.cc:17: Internal compiler error.
t002.cc:17: Please submit a full bug report to `bug-g++@prep.ai.mit.edu'.

Omitting either `-funroll-all-loops' or `-g' works, though.

If you need the expanded .ii file send me an e-mail.

And you guys from the gcc2 mailing  list, please add my e-mail address
to the To: or Cc: fields explicitly, as I  still couldn't get onto the
mailing list :-(

Manfred