Re: [Cbe-oss-dev] memalign weirdness in newlib

[Jeff Johnston <jjohnstn at redhat dot com>]

Patrick Mansfield wrote:
> [adding newlib list ...]
>
> On Sat, Jan 05, 2008 at 10:59:12AM +1100, Michael Ellerman wrote:
>
> > Yeah you're right, that was a stupid test case I whipped up, here's a
> > fixed version:
> >
> > int main(uint64_t spe_id, uint64_t data, uint64_t env)
> > {
> >         void *p, *q;
> >         int i;
> >
> >         for (i = 0x10; i < 0x90; i *= 2) {
> >                 p = memalign(i, 0x1000);
> >                 q = memalign(i, 0x1000);
> >                 printf("align = 0x%x p = %p q = %p\n", i, p, q);
> >         }
> >
> >         return 0;
> > }
> >
> > And the output:
> >
> > [michael@schoenaich bug]$ ./memalign 
> > align = 0x10 p = 0x1c20 q = 0x2e20
> > align = 0x20 p = 0x3e20 q = 0x4e60
> > align = 0x40 p = 0x5ec0 q = 0x5ec0
> > align = 0x80 p = 0x5f00 q = 0x5f00
> >
> >
> > Which is still broken AFAICT, for alignments > 0x20.
>
> Looks like a newlib bug.
>
> I tried your test case with mainline newlib, and get similar results, I
> only tried for SPU (CELL).

The test works fine for two 1.16.0 newlib local builds on my system 
(i686-linux-pc-gnu and mn10300-elf).

Could you debug further and isolate what is being passed to malloc, what 
is being passed to the low-level syscall, and finally what is being 
returned?

-- Jeff J.