>>> On 19.08.16 at 12:09, <andrew.coop...@citrix.com> wrote: > On 19/08/16 09:31, Jan Beulich wrote: >>>>> On 19.08.16 at 10:06, <wei.l...@citrix.com> wrote: >>> --- a/tools/firmware/hvmloader/hvmloader.c >>> +++ b/tools/firmware/hvmloader/hvmloader.c >>> @@ -272,8 +272,8 @@ const struct hvm_modlist_entry *get_module_entry( >>> >>> if ( !modlist || >>> info->modlist_paddr > UINTPTR_MAX || >>> - (info->modlist_paddr + info->nr_modules * sizeof(*modlist) - 1) >>> - > UINTPTR_MAX ) >>> + (info->modlist_paddr + >>> + (uint64_t)info->nr_modules * sizeof(*modlist) - 1) > UINTPTR_MAX >>> ) >>> return NULL; >> This can be had without resorting to 64-bit multiplication, by bounds >> checking >> >> (UINTPTR_MAX - (uintptr_t)info->modlist_paddr) / sizeof(*modlist) >> >> instead. While we would certainly hope that compilers don't resort >> to a libgcc helper for 64-bit multiplication, I think we'd better avoid >> that risk altogether. > > In this case, using libgcc would cause a link error because of > -fno-builtin, so I don't think it is too bad.
And it's this link error which I want to avoid. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel