From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 19 Oct 2022 14:45:02 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ol8RU-000gu9-7R for lore@lore.pengutronix.de; Wed, 19 Oct 2022 14:45:02 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ol8RR-00017l-8j for lore@pengutronix.de; Wed, 19 Oct 2022 14:45:01 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=q09IZMslUiEwllCJpI7JpA5EPzqUiW0tVWhNHRMZxeI=; b=JpgWIO4eEK2m+HyeRXGHEXr3If 4+6LqWY+qW2+wFF12KydElGQe+Uwwn/Z098XLhqZjdbrb4y51NU9O5zWdbWVggLr/nswjAdcJIaCl +4W7wY4wiSmr+zPszeSKE2T37WZsY1ZxTRhUN6Vdo3wqmqUEE5L+7ojhRLbsh1o4ru8hXabldm976 gYjxiguP2k+PswrwucQreh0cz52BITUmx00Sv7ncDJcTr/jkrBE8MZSznSD/D6mzuWx533ZZ85xF9 NH4a1c0/9iMGoM7fu2iVukHns/VSHt5R/QuUb1SqeNG39sMu40w5q3yYnb4kKjBeDQpgfma/uLEjO LDbywddQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ol8QA-001cL3-71; Wed, 19 Oct 2022 12:43:42 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ol8Q4-001c4s-Uo for barebox@lists.infradead.org; Wed, 19 Oct 2022 12:43:38 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ol8Q3-0000u7-FY; Wed, 19 Oct 2022 14:43:35 +0200 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1ol8Q2-0007jQ-P3; Wed, 19 Oct 2022 14:43:34 +0200 Received: from afa by dude04.red.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1ol8Q2-007MEI-6U; Wed, 19 Oct 2022 14:43:34 +0200 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Wed, 19 Oct 2022 14:43:33 +0200 Message-Id: <20221019124333.1753693-1-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221019_054337_013690_A291004B X-CRM114-Status: GOOD ( 10.50 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.7 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH master] Kbuild: disable ARM64 pointer authentication X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) The aarch64 cross-compiler built with Yocto's kirkstone release configures -mbranch-protection=standard as default. The resulting PACIASP/AUTIASP instructions are interpreted as NOPs by existing CPUs, but they increase image size and misalign the barebox header in ENTRY_FUNCTION(). Also on ARMv8.3+, where they serve a purpose, we wouldn't benefit from them as we don't setup any pointer authentication keys. Thus disable it. This fixes a breakage to the extended firmware mechanism when building my i.MX8M barebox with the Kirkstone toolchain. Signed-off-by: Ahmad Fatoum --- This is a workaround. ENTRY_FUNCTION() should be rewritten for ARM64, so we don't expect function prologue to be exactly two bytes long. --- Makefile | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Makefile b/Makefile index 98da09f18523..3737265316e9 100644 --- a/Makefile +++ b/Makefile @@ -659,6 +659,11 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-check) # Platforms that have their setjmp appropriately implemented may override this KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none) +# We don't have the necessary infrastructure to benefit from ARMv8.3+ pointer +# authentication. On older CPUs, they are interpreted as NOPs and blot the +# code and break less portable code that expects a very specific code layout +KBUILD_CFLAGS += $(call cc-option,-mbranch-protection=none) + KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) # Align the bit size of userspace programs with the kernel -- 2.30.2