* Xunlei Pang <[email protected]> wrote:
> > Hm, is the alloc_cpumask_var() done in alloc_sched_domains() safe?
>
> Until now, I haven't found any other similar issues, but I will check further.
>
> >
> > At least the usage pattern in init_sched_domains() looks unsafe:
> >
> > doms_cur = alloc_sched_domains(ndoms_cur);
> > if (!doms_cur)
> > doms_cur = &fallback_doms;
> > cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
So is this pattern in init_sched_domains() correct, for OFFSTACK=y?
It looks wrong to me, as alloc_sched_domains() allocates an uninitialized
cpumask
via alloc_cpumask_var() and returns it:
cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
{
int i;
cpumask_var_t *doms;
doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL);
if (!doms)
return NULL;
for (i = 0; i < ndoms; i++) {
if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) {
free_sched_domains(doms, i);
return NULL;
}
}
return doms;
}
and then this code:
> > cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
uses it without first clearing it.
So is this another such bug, or am I missing something?
Thanks,
Ingo
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