Re: [PATCH v4] page_alloc: assert IRQs are enabled in heap alloc/free

[Julien Grall <julien@xxxxxxx>]

On 26/04/2022 15:14, Julien Grall wrote:
> On 26/04/2022 15:01, Jan Beulich wrote:
> > On 25.04.2022 15:28, David Vrabel wrote:
> > > --- a/xen/common/page_alloc.c
> > > +++ b/xen/common/page_alloc.c
> > > @@ -162,6 +162,13 @@
> > >   static char __initdata opt_badpage[100] = "";
> > >   string_param("badpage", opt_badpage);
> > > +/*
> > > + * Heap allocations may need TLB flushes which require IRQs to be
> > > + * enabled (except when only 1 PCPU is online).
> > > + */
> > > +#define ASSERT_ALLOC_CONTEXT() \
> > > +    ASSERT(!in_irq() && (local_irq_is_enabled() || num_online_cpus() 
> > > <= 1))
> > At least one of these tightened assertions triggers on Arm, as per the
> > most recent smoke flight. I'm going to revert this for the time being.
>  From the serial console [1]:
>
> (XEN) Xen call trace:
> (XEN)    [<0022a510>] alloc_xenheap_pages+0x120/0x150 (PC)
> (XEN)    [<00000000>] 00000000 (LR)
> (XEN)    [<002736ac>] arch/arm/mm.c#xen_pt_update+0x144/0x6e4
> (XEN)    [<002740d4>] map_pages_to_xen+0x10/0x20
> (XEN)    [<00236864>] __vmap+0x400/0x4a4
> (XEN)    [<0026aee8>] 
> arch/arm/alternative.c#__apply_alternatives_multi_stop+0x144/0x1ec
> (XEN)    [<0022fe40>] stop_machine_run+0x23c/0x300
> (XEN)    [<002c40c4>] apply_alternatives_all+0x34/0x5c
> (XEN)    [<002ce3e8>] start_xen+0xcb8/0x1024
> (XEN)    [<00200068>] arch/arm/arm32/head.o#primary_switched+0xc/0x1c
I have sent a formal patch:

https://lore.kernel.org/xen-devel/20220426200629.58921-1-julien@xxxxxxx/
Cheers,

--
Julien Grall