weird glibc bug?? (#0 0x153b94c in strlen () at soinit.c:59)

weird glibc bug?? (#0 0x153b94c in strlen () at soinit.c:59)

[Troy Benjegerdes]

I am completely and totally stumped.

I have been seeing various programs (everthing from the installer to scp
to apache) that have seemingly inexplicable segfaults since at least the
first glibc-2.1 was out (6 months ago?)

At first I thought this had been caused by a bug in 'strip', since a new
binutils fixed the problem.

this problem seems to have resurfaced again in recent glibc's.

in it's current incarnation, scp is segfaulting, and when I use gdb, I get
the following backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x153b94c in strlen () at soinit.c:59
soinit.c:59: No such file or directory.
(gdb) bt
#0  0x153b94c in strlen () at soinit.c:59
#1  0x151fda4 in _IO_vfprintf () at vfprintf.c:1554
#2  0x1523304 in buffered_vfprintf (s=0x15fd118, format=0x18047e0 "%s:
%s",
    args=0x7ffff1f0) at vfprintf.c:1747
#3  0x151e2f4 in _IO_vfprintf () at vfprintf.c:1554
#4  0x1803d4c in _SDA2_BASE_ ()
#5  0x18039dc in _SDA2_BASE_ ()
#6  0x18022ac in _SDA2_BASE_ ()
#7  0x1801ac4 in _SDA2_BASE_ ()
#8  0x14fd7d4 in __libc_start_main () at ../sysdeps/powerpc/elf/libc-sta

So, my first thought was that strip was buggy again, so I built scp and
didn't strip it.

It still segfaults when run from the command line. But it gets more
interesting: When run from gdb, the unstripped binary *doesn't* segfault!!

It seems as though depending on where things are aligned in memory either
triggers or masks the problem. I have heard a report that apache works
fine when built with '-g', and segfaults with a screwed up stack when not.
(this normally isn't noticeable with apache, since it occurs when
returning a 'page not found' error)

Someone please tell me I haven't gone of the deep end on this :-/

--------------------------------------------------------------------------
| Troy Benjegerdes    |       troy@microux.com     |    hozer@drgw.net   |
|    Unix is user friendly... You just have to be friendly to it first.  |
| This message composed with 100% free software.    http://www.gnu.org   |
--------------------------------------------------------------------------


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Re: weird glibc bug?? (#0 0x153b94c in strlen () at soinit.c:59)

[Martin Costabel]

Could this be an egcs bug? When i reported a similar bug (lines #0 and
#1 in the gdb output were the same) where gnuplot was segfaulting, Franz
Sirl and the others found out that it was related to the varargs bug in
egcs. Have a look at the linuxppc-dev archives from around April 15.
There should be a fix for this in egcs-1.1.2-1c.

According to the sources at http://gate.crashing.org/, the "official"
varargs fix is included in egcs-1.1.2-1e which I managed to compile from
the spec and patch files found at that site. And of course, gcc-2.95 is
probably fixed, too.

Hope this helps

--
Martin

Troy Benjegerdes wrote:
> 
> I am completely and totally stumped.
> 
> I have been seeing various programs (everthing from the installer to scp
> to apache) that have seemingly inexplicable segfaults since at least the
> first glibc-2.1 was out (6 months ago?)
> 
> At first I thought this had been caused by a bug in 'strip', since a new
> binutils fixed the problem.
> 
> this problem seems to have resurfaced again in recent glibc's.
> 
> in it's current incarnation, scp is segfaulting, and when I use gdb, I get
> the following backtrace:
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x153b94c in strlen () at soinit.c:59
> soinit.c:59: No such file or directory.
> (gdb) bt
> #0  0x153b94c in strlen () at soinit.c:59
> #1  0x151fda4 in _IO_vfprintf () at vfprintf.c:1554
> #2  0x1523304 in buffered_vfprintf (s=0x15fd118, format=0x18047e0 "%s:
> %s",
>     args=0x7ffff1f0) at vfprintf.c:1747
> #3  0x151e2f4 in _IO_vfprintf () at vfprintf.c:1554
> #4  0x1803d4c in _SDA2_BASE_ ()
> #5  0x18039dc in _SDA2_BASE_ ()
> #6  0x18022ac in _SDA2_BASE_ ()
> #7  0x1801ac4 in _SDA2_BASE_ ()
> #8  0x14fd7d4 in __libc_start_main () at ../sysdeps/powerpc/elf/libc-sta
> 
> So, my first thought was that strip was buggy again, so I built scp and
> didn't strip it.
> 
> It still segfaults when run from the command line. But it gets more
> interesting: When run from gdb, the unstripped binary *doesn't* segfault!!
> 
> It seems as though depending on where things are aligned in memory either
> triggers or masks the problem. I have heard a report that apache works
> fine when built with '-g', and segfaults with a screwed up stack when not.
> (this normally isn't noticeable with apache, since it occurs when
> returning a 'page not found' error)
> 
> Someone please tell me I haven't gone of the deep end on this :-/
> 
> --------------------------------------------------------------------------
> | Troy Benjegerdes    |       troy@microux.com     |    hozer@drgw.net   |
> |    Unix is user friendly... You just have to be friendly to it first.  |
> | This message composed with 100% free software.    http://www.gnu.org   |
> --------------------------------------------------------------------------

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Re: weird glibc bug?? (#0 0x153b94c in strlen () at soinit.c:59)

[Troy Benjegerdes]

On Sat, 19 Jun 1999, Martin Costabel wrote:

> Could this be an egcs bug? When i reported a similar bug (lines #0 and
> #1 in the gdb output were the same) where gnuplot was segfaulting, Franz
> Sirl and the others found out that it was related to the varargs bug in
> egcs. Have a look at the linuxppc-dev archives from around April 15.
> There should be a fix for this in egcs-1.1.2-1c.

I doubt it, as I compiled with egcs-1.1.2-12e. It might be possible that a
shared lib the program is linked with was compiled with a bad egcs, but I
doubt it.

> 
> According to the sources at http://gate.crashing.org/, the "official"
> varargs fix is included in egcs-1.1.2-1e which I managed to compile from
> the spec and patch files found at that site. And of course, gcc-2.95 is
> probably fixed, too.
> 
> Hope this helps
> 
> --
> Martin
> 
> Troy Benjegerdes wrote:
> > 
> > I am completely and totally stumped.
> > 
> > I have been seeing various programs (everthing from the installer to scp
> > to apache) that have seemingly inexplicable segfaults since at least the
> > first glibc-2.1 was out (6 months ago?)
> > 
> > At first I thought this had been caused by a bug in 'strip', since a new
> > binutils fixed the problem.
> > 
> > this problem seems to have resurfaced again in recent glibc's.
> > 
> > in it's current incarnation, scp is segfaulting, and when I use gdb, I get
> > the following backtrace:
> > 
> > Program received signal SIGSEGV, Segmentation fault.
> > 0x153b94c in strlen () at soinit.c:59
> > soinit.c:59: No such file or directory.
> > (gdb) bt
> > #0  0x153b94c in strlen () at soinit.c:59
> > #1  0x151fda4 in _IO_vfprintf () at vfprintf.c:1554
> > #2  0x1523304 in buffered_vfprintf (s=0x15fd118, format=0x18047e0 "%s:
> > %s",
> >     args=0x7ffff1f0) at vfprintf.c:1747
> > #3  0x151e2f4 in _IO_vfprintf () at vfprintf.c:1554
> > #4  0x1803d4c in _SDA2_BASE_ ()
> > #5  0x18039dc in _SDA2_BASE_ ()
> > #6  0x18022ac in _SDA2_BASE_ ()
> > #7  0x1801ac4 in _SDA2_BASE_ ()
> > #8  0x14fd7d4 in __libc_start_main () at ../sysdeps/powerpc/elf/libc-sta
> > 
> > So, my first thought was that strip was buggy again, so I built scp and
> > didn't strip it.
> > 
> > It still segfaults when run from the command line. But it gets more
> > interesting: When run from gdb, the unstripped binary *doesn't* segfault!!
> > 
> > It seems as though depending on where things are aligned in memory either
> > triggers or masks the problem. I have heard a report that apache works
> > fine when built with '-g', and segfaults with a screwed up stack when not.
> > (this normally isn't noticeable with apache, since it occurs when
> > returning a 'page not found' error)
> > 
> > Someone please tell me I haven't gone of the deep end on this :-/
> > 
> > --------------------------------------------------------------------------
> > | Troy Benjegerdes    |       troy@microux.com     |    hozer@drgw.net   |
> > |    Unix is user friendly... You just have to be friendly to it first.  |
> > | This message composed with 100% free software.    http://www.gnu.org   |
> > --------------------------------------------------------------------------
> 
> 

--------------------------------------------------------------------------
| Troy Benjegerdes    |       troy@microux.com     |    hozer@drgw.net   |
|    Unix is user friendly... You just have to be friendly to it first.  |
| This message composed with 100% free software.    http://www.gnu.org   |
--------------------------------------------------------------------------


[[ This message was sent via the linuxppc-dev mailing list.  Replies are ]]
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