From nobody Wed Sep 17 22:22:06 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D97EFC7618D for ; Tue, 14 Mar 2023 10:16:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230510AbjCNKQ6 (ORCPT ); Tue, 14 Mar 2023 06:16:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230422AbjCNKQa (ORCPT ); Tue, 14 Mar 2023 06:16:30 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C36A62B50; Tue, 14 Mar 2023 03:16:03 -0700 (PDT) Received: from localhost.localdomain (unknown [83.149.199.65]) by mail.ispras.ru (Postfix) with ESMTPSA id 030A94076B4A; Tue, 14 Mar 2023 10:16:02 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 030A94076B4A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1678788962; bh=2TBk4UGNyfMdd8W/1cZbwwWp3e8vekyx8UYv/A/vm5c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n7Aqkk4PHxxjuE63bO4ZIRC9Y0AVo/LT7B+S7ULrj9n9YXFKMslgpX/pqQKSCFWBA P/v4Um3LkciXoZZoy02NoCHPn62b/8Zj/4Pv/QsB5vENyGQ0e5TuBIYu2Uy0JeR+ov 2giwLsVCTjAUow1JZXXnhYFJ1SZyjHVmz4HIsd0I= From: Evgeniy Baskov To: Ard Biesheuvel Cc: Evgeniy Baskov , Borislav Petkov , Andy Lutomirski , Dave Hansen , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexey Khoroshilov , Peter Jones , Gerd Hoffmann , "Limonciello, Mario" , joeyli , lvc-project@linuxtesting.org, x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v5 07/27] x86/build: Check W^X of vmlinux during build Date: Tue, 14 Mar 2023 13:13:34 +0300 Message-Id: <79fbb728535596eea7b429fc3ed39adc3c775c8a.1678785672.git.baskov@ispras.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Check if there are simultaneously writable and executable program segments in vmlinux ELF image and fail build if there are any. This would prevent accidental introduction of RWX segments. Tested-by: Mario Limonciello Signed-off-by: Evgeniy Baskov --- arch/x86/boot/compressed/Makefile | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/M= akefile index 6b6cfe607bdb..0c6e25279ec1 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -112,12 +112,17 @@ vmlinux-objs-$(CONFIG_EFI) +=3D $(obj)/efi.o vmlinux-objs-$(CONFIG_EFI_MIXED) +=3D $(obj)/efi_mixed.o vmlinux-objs-$(CONFIG_EFI_STUB) +=3D $(objtree)/drivers/firmware/efi/libst= ub/lib.a =20 +quiet_cmd_objcopy_and_wx_check =3D $(quiet_cmd_objcopy) +cmd_objcopy_and_wx_check =3D if $(OBJDUMP) -p $< | grep "flags .wx" > /dev= /null; then \ + (echo >&2 "$<: Simultaneously writable and executable sections are = prohibited"; \ + /bin/false); else $(cmd_objcopy); fi + $(obj)/vmlinux: $(vmlinux-objs-y) FORCE $(call if_changed,ld) =20 OBJCOPYFLAGS_vmlinux.bin :=3D -R .comment -S $(obj)/vmlinux.bin: vmlinux FORCE - $(call if_changed,objcopy) + $(call if_changed,objcopy_and_wx_check) =20 targets +=3D $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmli= nux.relocs =20 --=20 2.39.2