On Thu, Jul 16, 2020 at 11:02:53AM +0200, Peter Zijlstra wrote:
> On Wed, Jul 15, 2020 at 01:32:27AM +0300, Jarkko Sakkinen wrote:
> > +void *text_alloc(unsigned long size)
> > +{
> > + void *p;
> > +
> > + if (PAGE_ALIGN(size) > MODULES_LEN)
> > + return NULL;
> > +
> > + p = __vmalloc_node_range(size, MODULE_ALIGN,
> > + MODULES_VADDR + get_module_load_offset(),
> > + MODULES_END, GFP_KERNEL,
> > + PAGE_KERNEL, 0, NUMA_NO_NODE,
> > + __builtin_return_address(0));
> > + if (p && (kasan_module_alloc(p, size) < 0)) {
> > + vfree(p);
> > + return NULL;
> > + }
> > +
> > + return p;
> > +}
> > +
> > +void text_free(void *region)
> > +{
> > + /*
> > + * This memory may be RO, and freeing RO memory in an interrupt is not
> > + * supported by vmalloc.
> > + */
> > + WARN_ON(in_interrupt());
>
> I think that wants to be:
>
> lockdep_assert_irqs_enabled();
>
> in_interrupt() isn't sufficient, interrupts must also not be disabled
> when issuesing TLB invalidations.
Shouldn't it be then also fixed in the module_memfree() fallback
implementation (kernel/module.c)?
/Jarkko
