From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1944) id 8E93B3858009; Fri, 5 Aug 2022 19:33:28 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8E93B3858009 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Szabolcs Nagy To: glibc-cvs@sourceware.org Subject: [glibc/arm/morello/main] cheri: don't use dl_random for pointer mangling X-Act-Checkin: glibc X-Git-Author: Szabolcs Nagy X-Git-Refname: refs/heads/arm/morello/main X-Git-Oldrev: 347f7e2ac1f34f92bc382afe9e5fe32ebe7cf16c X-Git-Newrev: ff2cd89ebb434232d96b192d1a383fff543aff01 Message-Id: <20220805193328.8E93B3858009@sourceware.org> Date: Fri, 5 Aug 2022 19:33:28 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Aug 2022 19:33:28 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ff2cd89ebb434232d96b192d1a383fff543aff01 commit ff2cd89ebb434232d96b192d1a383fff543aff01 Author: Szabolcs Nagy Date: Tue Mar 1 17:36:12 2022 +0000 cheri: don't use dl_random for pointer mangling Pointer mangling cannot be supported on capability architectures. And there is not enough bytes in dl_random for 128 bit pointers. Stack guard is still loaded from dl_random: stack protection is unlikely to be useful on a capability architecture, but it works. Diff: --- sysdeps/unix/sysv/linux/dl-osinfo.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sysdeps/unix/sysv/linux/dl-osinfo.h b/sysdeps/unix/sysv/linux/dl-osinfo.h index 7888915f12..b4104e0539 100644 --- a/sysdeps/unix/sysv/linux/dl-osinfo.h +++ b/sysdeps/unix/sysv/linux/dl-osinfo.h @@ -48,7 +48,12 @@ _dl_setup_stack_chk_guard (void *dl_random) static inline uintptr_t __attribute__ ((always_inline)) _dl_setup_pointer_guard (void *dl_random, uintptr_t stack_chk_guard) { +#ifdef __CHERI_PURE_CAPABILITY__ + /* Pointer mangling is not supported on capability architectures. */ + return 0; +#else uintptr_t ret; memcpy (&ret, (char *) dl_random + sizeof (ret), sizeof (ret)); return ret; +#endif }