From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932231AbeCKMjF (ORCPT ); Sun, 11 Mar 2018 08:39:05 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:52808 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932126AbeCKMi7 (ORCPT ); Sun, 11 Mar 2018 08:38:59 -0400 X-Google-Smtp-Source: AG47ELtdJTBY6jYKaKWUbCbN3SFN3URZykIGnEV5tNU0ZUjzhYFFIQKL4hbM0BsBbNsZGsxc1KC8rA== From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Arnd Bergmann , Kees Cook , Will Deacon , Michael Ellerman , Thomas Garnier , Thomas Gleixner , "Serge E. Hallyn" , Bjorn Helgaas , Benjamin Herrenschmidt , Russell King , Paul Mackerras , Catalin Marinas , Petr Mladek , Ingo Molnar , James Morris , Andrew Morton , Nicolas Pitre , Josh Poimboeuf , Steven Rostedt , Sergey Senozhatsky , Linus Torvalds , Jessica Yu , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org Subject: [PATCH v8 1/6] arch: enable relative relocations for arm64, power and x86 Date: Sun, 11 Mar 2018 12:38:10 +0000 Message-Id: <20180311123815.17916-2-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180311123815.17916-1-ard.biesheuvel@linaro.org> References: <20180311123815.17916-1-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before updating certain subsystems to use place relative 32-bit relocations in special sections, to save space and reduce the number of absolute relocations that need to be processed at runtime by relocatable kernels, introduce the Kconfig symbol and define it for some architectures that should be able to support and benefit from it. Cc: Catalin Marinas Cc: Will Deacon Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Thomas Gleixner Cc: Ingo Molnar Cc: x86@kernel.org Signed-off-by: Ard Biesheuvel --- arch/Kconfig | 10 ++++++++++ arch/arm64/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/x86/Kconfig | 1 + 4 files changed, 13 insertions(+) diff --git a/arch/Kconfig b/arch/Kconfig index 76c0b54443b1..4e624f75823a 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -975,4 +975,14 @@ config REFCOUNT_FULL against various use-after-free conditions that can be used in security flaw exploits. +config HAVE_ARCH_PREL32_RELOCATIONS + bool + help + May be selected by an architecture if it supports place-relative + 32-bit relocations, both in the toolchain and in the module loader, + in which case relative references can be used in special sections + for PCI fixup, initcalls etc which are only half the size on 64 bit + architectures, and don't require runtime relocation on relocatable + kernels. + source "kernel/gcov/Kconfig" diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7381eeb7ef8e..7c543667703e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -91,6 +91,7 @@ config ARM64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT + select HAVE_ARCH_PREL32_RELOCATIONS select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 73ce5dd07642..21d5ad1608d8 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -181,6 +181,7 @@ config PPC select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT + select HAVE_ARCH_PREL32_RELOCATIONS select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_CBPF_JIT if !PPC64 diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c1236b187824..1c6e2ddd2fdc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -117,6 +117,7 @@ config X86 select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT + select HAVE_ARCH_PREL32_RELOCATIONS select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK -- 2.15.1