From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v2 07/29] x86: Restore "text" Program Header with dummy section Date: Thu, 10 Oct 2019 17:05:47 -0700 Message-ID: <20191011000609.29728-8-keescook@chromium.org> References: <20191011000609.29728-1-keescook@chromium.org> Return-path: In-Reply-To: <20191011000609.29728-1-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Borislav Petkov Cc: Kees Cook , Rick Edgecombe , Dave Hansen , Andy Lutomirski , Arnd Bergmann , Michael Ellerman , Heiko Carstens , Will Deacon , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-c6x-dev@linux-c6x.org, Yoshinori Sato , Michal Simek , linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org, x86@kernel.org, linux-kernel@vger.kernel.org List-Id: linux-arch.vger.kernel.org In a linker script, if once places a section in one or more segments using ":PHDR", then the linker will place all subsequent allocatable sections, which do not specify ":PHDR", into the same segments. In order to have the NOTES section in both PT_LOAD (":text") and PT_NOTE (":note"), both segments are marked, and the only way to to undo this to keep subsequent sections out of PT_NOTE is to mark the following section with just the single desired PT_LOAD (":text"). In preparation for having a common NOTES macro, perform the segment assignment use a dummy section (as done by other architectures). Signed-off-by: Kees Cook --- arch/x86/kernel/vmlinux.lds.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index e2feacf921a0..788e78978030 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -147,8 +147,9 @@ SECTIONS } :text = 0x9090 NOTES :text :note + .dummy : { *(.dummy) } :text - EXCEPTION_TABLE(16) :text = 0x9090 + EXCEPTION_TABLE(16) /* .text should occupy whole number of pages */ . = ALIGN(PAGE_SIZE); -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f193.google.com ([209.85.210.193]:44625 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727545AbfJKAG1 (ORCPT ); Thu, 10 Oct 2019 20:06:27 -0400 Received: by mail-pf1-f193.google.com with SMTP id q21so4923131pfn.11 for ; Thu, 10 Oct 2019 17:06:27 -0700 (PDT) From: Kees Cook Subject: [PATCH v2 07/29] x86: Restore "text" Program Header with dummy section Date: Thu, 10 Oct 2019 17:05:47 -0700 Message-ID: <20191011000609.29728-8-keescook@chromium.org> In-Reply-To: <20191011000609.29728-1-keescook@chromium.org> References: <20191011000609.29728-1-keescook@chromium.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Borislav Petkov Cc: Kees Cook , Rick Edgecombe , Dave Hansen , Andy Lutomirski , Arnd Bergmann , Michael Ellerman , Heiko Carstens , Will Deacon , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-c6x-dev@linux-c6x.org, Yoshinori Sato , Michal Simek , linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org, x86@kernel.org, linux-kernel@vger.kernel.org Message-ID: <20191011000547.f2t5tU60RL2sMXrE3IdWDzLUrDn7kSPaJNcnQJDYJzg@z> In a linker script, if once places a section in one or more segments using ":PHDR", then the linker will place all subsequent allocatable sections, which do not specify ":PHDR", into the same segments. In order to have the NOTES section in both PT_LOAD (":text") and PT_NOTE (":note"), both segments are marked, and the only way to to undo this to keep subsequent sections out of PT_NOTE is to mark the following section with just the single desired PT_LOAD (":text"). In preparation for having a common NOTES macro, perform the segment assignment use a dummy section (as done by other architectures). Signed-off-by: Kees Cook --- arch/x86/kernel/vmlinux.lds.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index e2feacf921a0..788e78978030 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -147,8 +147,9 @@ SECTIONS } :text = 0x9090 NOTES :text :note + .dummy : { *(.dummy) } :text - EXCEPTION_TABLE(16) :text = 0x9090 + EXCEPTION_TABLE(16) /* .text should occupy whole number of pages */ . = ALIGN(PAGE_SIZE); -- 2.17.1