On 1/15/20 6:42 AM, Andrey Konovalov wrote: >> - max_addr = user_addr_max(); >> - src_addr = (unsigned long)untagged_addr(src); > > If you end up changing this code, you need to keep the untagged_addr() > logic, otherwise this breaks arm64 tagged address ABI [1]. It is moot point now, but fwiw untagged_addr() would not have been needed anymore as it was only needed to compute the pointer difference which my patch got rid of. > > [1] https://www.kernel.org/doc/html/latest/arm64/tagged-address-abi.html > >> - if (likely(src_addr < max_addr)) { >> - unsigned long max = max_addr - src_addr; >> + kasan_check_write(dst, count); >> + check_object_size(dst, count, false); >> + if (user_access_begin(src, count)) {
