brk() problem in glibc 2.3.2 on TQM860

brk() problem in glibc 2.3.2 on TQM860

[Karim Yaghmour]

I've been having problems with brk() calls (like ones made by malloc() to the
kernel) when using glibc 2.3.2 on a TQM860 (16MB RAM, 8MB of flash.) Take the
following snippet of code for example:
	for (i = 1, val = 10; i < 10; val = val * 10, i++) {
		printf("Allocating %lu \n", val);
		x = (void*) malloc(val);
		memset(x, '\0', val);
	}

This always succeeds in allocating 100,000 bytes, but it's always freezing when
trying to allocate 10^6. The kernel isn't dead. In fact I can start this in the
background, but the fact of the matter is that it's never coming back from that
10^6 malloc.

This wouldn't be so anoying if it weren't reflecting in the execution of some
key applications ... like insmod.

There are two patches that were applied to this glibc, both from Dan Kegel
(neither of which should really make any difference):
- without-fp
- sscanf

Here's the configuration line for glibc 2.3.2:
$ CC=powerpc-linux-gcc CFLAGS="-O2 -D_SOFT_FLOAT -mcpu=860" \
 > ../glibc-2.3.2/configure --host=$TARGET --build=i686-linux \
 > --prefix="/usr" --enable-add-ons \
 > --with-headers=${TARGET_PREFIX}/include --without-fp

Also using:
- binutils 2.14
- gcc 3.3.2
- Linux 2.4.25 (vanilla; non-vanilla or other versions make no difference.)

The same code works fine an IceCube, granted with a different glibc config line.

If anyone's seen this before and has a fix, please let me know.

Thanks,

Karim
--
Author, Speaker, Developer, Consultant
Pushing Embedded and Real-Time Linux Systems Beyond the Limits
http://www.opersys.com || karim@opersys.com || 1-866-677-4546


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: brk() problem in glibc 2.3.2 on TQM860

[Karim Yaghmour]

... Pilot error ...

Karim Yaghmour wrote:
> I've been having problems with brk() calls (like ones made by malloc()
> to the
> kernel) when using glibc 2.3.2 on a TQM860 (16MB RAM, 8MB of flash.)
> Take the
> following snippet of code for example:
>     for (i = 1, val = 10; i < 10; val = val * 10, i++) {
>         printf("Allocating %lu \n", val);
>         x = (void*) malloc(val);
>         memset(x, '\0', val);
>     }

It actually freezes in the memset() and the problem is the memset.S file in
glibc-2.3.2/sysdeps/powerpc/powerpc32/ which needs to be removed. I knew
this problem existed in older versions of glibc, but I had assumed that it
had been fixed in the newer versions ... I assumed wrong.

When the file is removed everything works fine.

Karim
--
Author, Speaker, Developer, Consultant
Pushing Embedded and Real-Time Linux Systems Beyond the Limits
http://www.opersys.com || karim@opersys.com || 1-866-677-4546


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/