Re: [Jamvm-general] Error: Malloc failed - aborting VM...

[Robert L. <rob...@gm...>]

Hi,

Yes, I expected you'd get further and fail again.  The problem this
time is that the PowerPC 405GP doesn't support floating point (hence
the illegal instruction).

I expect you're cross-compiling.   Can you send the output of
<cross-compiler> -dumpspecs?

Your tool-chain should be producing code with floating point done in
software using integer instructions (i.e. -msoft-float).  The problem
is that there is some hand-written assembler in JamVM which handles
creation of a C call-frame for calling JNI methods.

This code follows the PowerPC calling-convention, and passes
floating-point values in floating-point registers.  On a 405GP,
therefore, calling any JNI method with floating-point parameters will
fail with an illegal instruction.

I will need to do some experimentation to find out how the
calling-convention is changed when soft-float is enabled.  I expect a
simple hack to treat float as int, and double as long will work but I
can't gaurantee it.  Apply the attached patch:

cd jamvm-1.4.3/src/os/linux/powerpc
patch < patch

Note, as I'm in work at the moment I can't even gaurantee that this
will compile (assemble)!

Rob.

On 10/23/06, Thanh Nguyen <TH...@te...> wrote:
> Hi,
>
> Thanks for your quick answer. I have fixed the problem as you recommanded
> below. But I got another issue. Now after loading the class
> java/util/AbstractCollection, it gave me an error : Illegal instruction.
>
> /jamvm $ bin/jamvm HelloWorld
>
> /****** just a printf after : classblock->interfaces =3D (Class
> **)sysMalloc(intf_count * sizeof(Class *)); ****/
> size : 16 classname : java/lang/Class, data : 268810040, file_len : 15719
> size : 0 classname : java/io/Serializable, data : 268836416, file_len : 1=
13
> size : 0 classname : java/lang/Object, data : 268836536, file_len : 1931
> size : 0 classname : java/lang/reflect/Type, data : 268838872, file_len :
> 107
> size : 0 classname : java/lang/reflect/AnnotatedElement,
> data : 268838992, file_len : 360
> size : 0 classname : java/lang/reflect/GenericDeclaration,
> data : 268839552, file_len : 201
> size : 4 classname : java/lang/Thread, data : 268795400, file_len : 8404
> size : 0 classname : java/lang/Runnable, data : 268814600, file_len : 127
> size : 0 classname : java/lang/VMThread, data : 268821776, file_len : 148=
1
> size : 12 classname : java/lang/String, data : 268846160, file_len : 1564=
5
> size : 0 classname : java/lang/Comparable, data : 268801744, file_len : 1=
55
> size : 0 classname : java/lang/CharSequence, data : 268802088, file_len :
> 257
> size : 0 classname : java/lang/Cloneable, data : 268858880, file_len : 10=
9
> size : 4 classname : java/lang/ThreadGroup, data : 268869128, file_len :
> 6755
> size : 0 classname :
> java/lang/Thread$UncaughtExceptionHandler, data :
> 268875888, file_len : 281
> size : 16 classname : java/util/Vector, data : 268877152, file_len : 7133
> size : 4 classname : java/util/List, data : 268872776, file_len : 915
> size : 4 classname : java/util/Collection, data : 268874080, file_len : 5=
58
> size : 0 classname : java/lang/Iterable, data : 268874920, file_len : 151
> size : 0 classname : java/util/RandomAccess, data : 268874920, file_len :
> 115
> size : 4 classname : java/util/AbstractList, data : 268895008, file_len :
> 3074
> size : 4 classname : java/util/AbstractCollection, data : 268902192,
> file_len : 2870
>
> /****************************/
>
> Illegal instruction
>
> Have you any idea about that ?
> Thanks a lot for your help.
>
> NT
>
> Le lundi 23 octobre 2006 =E0 13:20 +0100, Robert Lougher a =E9crit :
> Hi,

A better "fix" is to change:

 if(mem =3D=3D NULL) {

to
 if(mem =3D=3D NULL &&
> n !=3D 0) {

The code doesn't try to access the returned memory if the size is
> 0,
and free(0) shoud do nothing...

Rob.

On 10/23/06, Robert Lougher
> <rob...@gm...> wrote:
> Hi,
>
> I suspect you're using uclib rather
> glibc. In one or two places in
> JamVM there can be calls to malloc(0), e.g.
> if a class has no
> interfaces. Under glibc this returns a valid pointer,
> while under
> uclib it doesn't.
>
> Easy way to "fix" is to put an extra
> line at the start of sysMalloc:
>
> if(n =3D=3D 0) n =3D 1;
>
> This is a hack.
> The proper fix is to remove the couple of calls to
> malloc(0). I'll try and
> do this for the next release.
>
> Rob.
>
> On 10/23/06, Thanh Nguyen
> <TH...@te...> wrote:
> > Hi all,
> >
> > I'm trying to use jamVM on a
> plate-forme IBM Powerpc 405GP with 32MB of
> > Flash and 64MB of RAM.
> Actually, this plate-forme is running under
> > Montavista Linux. I have
> compiled the GNU Classpath 0.91 and jamvm-1.4.3
> > successfully. I have a
> simple byte-code java class named HelloWold that I
> > could execute
> successfully with jamvm on PC Ubuntu. When I tried to execute
> > it with
> this command :
> > #jamvm HelloWorld
> >
> > I got an error : Malloc failed
> - aborting VM...
> >
> > After searching a little bit, I found that this
> message is generated in the
> > funtion (in alloc.c) :
> > /* ------
> Allocation from system heap ------- */
> >
> > void *sysMalloc(int n) {
> >
> void *mem =3D malloc(n);
> >
> > if(mem =3D=3D NULL) {
> > fprintf(stderr, "Malloc
> failed - aborting VM...\n");
> > exitVM(1);
> > }
> >
> > return mem;
> >
> }
> >
> > It seems that jamvm can not intialize "Main thread" with the
> function
> > initialiseMainThread(java_stack) which is
> defined in the
> > Thread.h. At a given moment, this function calls
> >
> findSystemClass0("java/lang/Thread") that itself calls
> >
> loadSystemClass and defineClass. When defineClass is called, it loads ste=
p
>
> > by step all java base classes like java/lang/classes,
> java/io/Serializable
> > etc.
> >
> > I found out that after loading
> java/lang/classes, jamvm stopped at
> > java/io/serializable and gave the
> error message : Malloc failed - aborting
> > VM... caused by the failure of
> the execution : interfaces =3D
> > classblock->interfaces =3D (Class
> **)sysMalloc(intf_count * sizeof(Class *));
> > in the defineClass
> function.
> >
> > Does anybody know about this error or got it in the
> past?
> >
> > Thank you in advance.
> >
> > NT
> >
> >
> >
> >
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