From: Julien Grall Date: Fri, 6 Oct 2017 13:22:08 +0000 (+0200) Subject: xen/page_alloc: Cover memory unreserved after boot in first_valid_mfn X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=709230fac2d3150c938c3697c63bfaf11fda17c4;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 master commit: ec6d9023e1f54cdccbf2e4c63cf947f1be2b1e8e master date: 2017-09-29 13:22:52 -0700 --- diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 7d6d20c00a..92d9c14f06 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -1190,6 +1190,16 @@ 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));