From: Julien Grall Date: Fri, 29 Sep 2017 20:16:21 +0000 (-0700) Subject: xen/page_alloc: Cover memory unreserved after boot in first_valid_mfn X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~1288 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ec6d9023e1f54cdccbf2e4c63cf947f1be2b1e8e;p=xen.git xen/page_alloc: Cover memory unreserved after boot in first_valid_mfn On Arm, some regions (e.g Initramfs, Dom0 Kernel...) are marked as reserved until the hardware domain is built and they are copied into its memory. Therefore, they will not be added in the boot allocator via init_boot_pages. Instead, init_xenheap_pages will be called once the region are not used anymore. Update first_valid_mfn in both init_heap_pages and init_boot_pages (already exist) to cover all the cases. This is XSA-245. Signed-off-by: Julien Grall [Adjust comment, added locking around first_valid_mfn update] Signed-off-by: Boris Ostrovsky Acked-by: Stefano Stabellini Reported-and-Tested-by: Konrad Rzeszutek Wilk --- diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 0b9f6cc6df..fbe5a8af39 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -1700,6 +1700,16 @@ static void init_heap_pages( { unsigned long i; + /* + * Some pages may not go through the boot allocator (e.g reserved + * memory at boot but released just after --- kernel, initramfs, + * etc.). + * Update first_valid_mfn to ensure those regions are covered. + */ + spin_lock(&heap_lock); + first_valid_mfn = min_t(unsigned long, page_to_mfn(pg), first_valid_mfn); + spin_unlock(&heap_lock); + for ( i = 0; i < nr_pages; i++ ) { unsigned int nid = phys_to_nid(page_to_maddr(pg+i));