Messages in this thread | | | Date | Mon, 20 Jun 2011 20:16:01 +0100 | From | Stefano Stabellini <> | Subject | Re: [Xen-devel] [PATCH 1/3] x86: calculate precisely the memory needed by init_memory_mapping |
| |
On Fri, 17 Jun 2011, Ian Jackson wrote: > stefano.stabellini@eu.citrix.com writes ("[Xen-devel] [PATCH 1/3] x86: calculate precisely the memory needed by init_memory_mapping"): > > + if (pgt_buf_end != pgt_buf_top) > > + printk(KERN_DEBUG "initial kernel pagetable allocation wasted %lx" > > + " pages\n", pgt_buf_top - pgt_buf_end); > > If (due to a bug) pgt_buf_end > pgt_buf_top, this will printk a > message about wasting a negative number of pages, rather than > crashing. Is there something else that will catch this case ?
Thanks for reviewing this patch!
Yes, there is something else that catches this case: both the 32 bit and the 64 bit versions of alloc_low_page contain this code:
unsigned long pfn = pgt_buf_end++;
if (pfn >= pgt_buf_top) panic("alloc_low_page: ran out of memory");
so we are safe from that point of view.
| |