Re: Hi, Needs suggestions for finding and fixing stack/memory corruption when calling a function

[Fawad Lateef <fawadlateef@gmail.com>]

Hi,

Just want to say thanks for helping me and want to post solution which
worked for me; so that anyone facing similar issue can try this.

I used -O2 rather than -Os in my compiler options and the problem
vanished from all components. So somehow using option -Os optimizes
the size _but_ seems to be messing with function arguments (I looked
at assembler code generated by armv5l-linux-gcc and found big
differences in argument passing between -Os and -O2).
So my current compiler options are:

armv5l-linux-g++ -Wall -Wno-write-strings -mcpu=arm9 -O2
-DARM9_LINUX_GCC -D_GNU_SOURCE -DUNIX -pipe -fPIC -c -o xxxxxxx.o
xxxxxxx.cc

Regards,

-- Fawad Lateef

P.S. I did top-posting rather than bottom-posting because I am not
replying to some comments.


On Wed, May 25, 2011 at 12:07 PM, Glynn Clements
<glynn@gclements.plus.com> wrote:
>
> Fawad Lateef wrote:
>
> > > Personally, I'd be more inclined to suspect register corruption. Are
> > > you calling a library function which use a different ABI? E.g. if your
> > > code is compiled for an ABI where certain registers are preserved but
> > > calling a function using an ABI which doesn't preserver those
> > > registers, then you'll have problems.
> >
> > humm, Can you give some suggestion about how to verify this ? Using
> > readelf or objdump on different libraries and executables can give
> > some clue ? As we are using some pre-compiled  libraries provided by
> > some stack we are using.
>
> The files themselves may not contain sufficient information. E.g. if
> someone builds a library using e.g. -mregparm=3, that isn't going to
> show up in the objdump (etc) output. First, check the documentation
> for the libraries; if that doesn't help, try disassembling them.
>
> --
> Glynn Clements <glynn@gclements.plus.com>
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