From mboxrd@z Thu Jan 1 00:00:00 1970 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 00F83C4167B for ; Sun, 2 Oct 2022 23:00:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230323AbiJBW7d (ORCPT ); Sun, 2 Oct 2022 18:59:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230498AbiJBW6k (ORCPT ); Sun, 2 Oct 2022 18:58:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E7FC4151F; Sun, 2 Oct 2022 15:55:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B25C060EBA; Sun, 2 Oct 2022 22:53:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73B54C433D6; Sun, 2 Oct 2022 22:52:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664751180; bh=ib1lQCV01pXW8JO0BmnZksOwhGMo3P498BUfkCHG5/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VyWO1TQ2LabdFwZg5TrnA/8xfYVAfpwxz2MDdRX43jt/XKp/INBk6XwtlVGNQ4BTN hc9kcYUJOvotTh2EYFyb3UrshO62Wn/rlAIKn8X3T2UDqaTxu5BnD83BZiP3RCFM+2 4j1Ovjr72x44AGd4HdsMgnV4kKa5/VIetkL6btONV62GBvEREl/qm8jQGJR2BX7EsD uVMaaC9Nvip2ee9MwNBlOSFBQDPEfjf9+lUvdk0T7fx0gWkMAs8R2WIMRKyJlgT+ry kC+CBAAthx4LM4ve4Y63xwk9a3q06FgepEEHCYFI/f2iOqtNFNZVlVD+uIWYbOi0Zh pgC0/MmS+pxaw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Gow , Lukas Straub , Randy Dunlap , Richard Weinberger , Sasha Levin , anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, trishalfonso@google.com, andreyknvl@gmail.com, linux-um@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 9/9] arch: um: Mark the stack non-executable to fix a binutils warning Date: Sun, 2 Oct 2022 18:52:36 -0400 Message-Id: <20221002225236.239675-9-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221002225236.239675-1-sashal@kernel.org> References: <20221002225236.239675-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Gow [ Upstream commit bd71558d585ac61cfd799db7f25e78dca404dd7a ] Since binutils 2.39, ld will print a warning if any stack section is executable, which is the default for stack sections on files without a .note.GNU-stack section. This was fixed for x86 in commit ffcf9c5700e4 ("x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments"), but remained broken for UML, resulting in several warnings: /usr/bin/ld: warning: arch/x86/um/vdso/vdso.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: .tmp_vmlinux.kallsyms1 has a LOAD segment with RWX permissions /usr/bin/ld: warning: .tmp_vmlinux.kallsyms1.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: .tmp_vmlinux.kallsyms2 has a LOAD segment with RWX permissions /usr/bin/ld: warning: .tmp_vmlinux.kallsyms2.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: vmlinux has a LOAD segment with RWX permissions Link both the VDSO and vmlinux with -z noexecstack, fixing the warnings about .note.GNU-stack sections. In addition, pass --no-warn-rwx-segments to dodge the remaining warnings about LOAD segments with RWX permissions in the kallsyms objects. (Note that this flag is apparently not available on lld, so hide it behind a test for BFD, which is what the x86 patch does.) Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ffcf9c5700e49c0aee42dcba9a12ba21338e8136 Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107 Signed-off-by: David Gow Reviewed-by: Lukas Straub Tested-by: Lukas Straub Acked-by: Randy Dunlap # build-tested Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin --- arch/um/Makefile | 8 ++++++++ arch/x86/um/vdso/Makefile | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/um/Makefile b/arch/um/Makefile index 275f5ffdf6f0..773120be0f56 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -132,10 +132,18 @@ export LDS_ELF_FORMAT := $(ELF_FORMAT) # The wrappers will select whether using "malloc" or the kernel allocator. LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc +# Avoid binutils 2.39+ warnings by marking the stack non-executable and +# ignorning warnings for the kallsyms sections. +LDFLAGS_EXECSTACK = -z noexecstack +ifeq ($(CONFIG_LD_IS_BFD),y) +LDFLAGS_EXECSTACK += $(call ld-option,--no-warn-rwx-segments) +endif + LD_FLAGS_CMDLINE = $(foreach opt,$(KBUILD_LDFLAGS),-Wl,$(opt)) # Used by link-vmlinux.sh which has special support for um link export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE) +export LDFLAGS_vmlinux := $(LDFLAGS_EXECSTACK) # When cleaning we don't include .config, so we don't include # TT or skas makefiles and don't clean skas_ptregs.h. diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile index 0caddd6acb22..bec115036f87 100644 --- a/arch/x86/um/vdso/Makefile +++ b/arch/x86/um/vdso/Makefile @@ -62,7 +62,7 @@ quiet_cmd_vdso = VDSO $@ -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \ sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' -VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv +VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack GCOV_PROFILE := n # -- 2.35.1