On Fri, 9 Jun 2017 08:22:26 +0000 Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > Existing code that uses vmalloc_to_page() may assume that any > address for which is_vmalloc_addr() returns true may be passed > into vmalloc_to_page() to retrieve the associated struct page. > > This is not un unreasonable assumption to make, but on architectures > that have CONFIG_HAVE_ARCH_HUGE_VMAP=y, it no longer holds, and we > need to ensure that vmalloc_to_page() does not go off into the weeds > trying to dereference huge PUDs or PMDs as table entries. > > Given that vmalloc() and vmap() themselves never create huge > mappings or deal with compound pages at all, there is no correct > answer in this case, so return NULL instead, and issue a warning. Is this patch known to fix any current user-visible problem? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
