Re: [PATCH v12 01/11] x86: text_poke() may access uninitialized struct pages

[Thomas Gleixner]

On Mon, 25 Jun 2018, Peter Zijlstra wrote:
> On Thu, Jun 21, 2018 at 05:25:08PM -0400, Pavel Tatashin wrote:
> > -void *text_poke(void *addr, const void *opcode, size_t len)
> > +void __ref *text_poke(void *addr, const void *opcode, size_t len)
> >  {
> >  	unsigned long flags;
> >  	char *vaddr;
> >  	struct page *pages[2];
> >  	int i;
> >  
> > +	/* While boot memory allocator is runnig we cannot use struct
> 
> Broken comment style..
> 
> > +	 * pages as they are not yet initialized. However, we also know
> > +	 * that this is early in boot, and it is safe to fallback to
> > +	 * text_poke_early.
> > +	 */
> > +	if (unlikely(!after_bootmem))
> > +		return text_poke_early(addr, opcode, len);
> 
> I'm not entirely sure this is right.. Because not only do we need the
> whole fixmap stuff working, we also need #DB and the IPI handlers set-up
> and working.

IPI? That's early UP boot why would you need an IPI?

Thanks,

	tglx