From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <39e063ad-208d-f5f0-9807-eedcf0db1692@infradead.org> Date: Fri, 26 Aug 2022 13:35:13 -0700 MIME-Version: 1.0 Subject: Re: [PATCH] arch: um: Mark the stack non-executable to fix a binutils warning Content-Language: en-US References: <20220823010830.2675419-1-davidgow@google.com> From: Randy Dunlap In-Reply-To: <20220823010830.2675419-1-davidgow@google.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: David Gow , Richard Weinberger , Anton Ivanov , Johannes Berg , Nick Desaulniers Cc: Thomas Gleixner , Ingo Molnar , Dave Hansen , Linus Torvalds , Brendan Higgins , Daniel Latypov , linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, kunit-dev@googlegroups.com, x86@kernel.org On 8/22/22 18:08, David Gow wrote: > 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 Acked-by: Randy Dunlap # build-tested Thanks. > --- > arch/um/Makefile | 9 ++++++++- > arch/x86/um/vdso/Makefile | 2 +- > 2 files changed, 9 insertions(+), 2 deletions(-) -- ~Randy _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um