From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753307AbdLYUzt (ORCPT ); Mon, 25 Dec 2017 15:55:49 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:46275 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753235AbdLYUzf (ORCPT ); Mon, 25 Dec 2017 15:55:35 -0500 X-Google-Smtp-Source: ACJfBotJqEF4AzBdlQ9WvPmZlo2Y4TFclh0gtk2pMwFp0BFOk8FVD97q5jqfKG37YLKwrHDEH+Helg== From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: Ard Biesheuvel , "H. Peter Anvin" , Ralf Baechle , Arnd Bergmann , Heiko Carstens , Kees Cook , Will Deacon , Michael Ellerman , Thomas Garnier , Thomas Gleixner , "Serge E. Hallyn" , Bjorn Helgaas , Benjamin Herrenschmidt , Russell King , Paul Mackerras , Catalin Marinas , "David S. Miller" , Petr Mladek , Ingo Molnar , James Morris , Andrew Morton , Nicolas Pitre , Josh Poimboeuf , Steven Rostedt , Martin Schwidefsky , Sergey Senozhatsky , Linus Torvalds , Jessica Yu , linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: [PATCH v5 4/8] PCI: Add support for relative addressing in quirk tables Date: Mon, 25 Dec 2017 20:54:36 +0000 Message-Id: <20171225205440.14575-5-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171225205440.14575-1-ard.biesheuvel@linaro.org> References: <20171225205440.14575-1-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Allow the PCI quirk tables to be emitted in a way that avoids absolute references to the hook functions. This reduces the size of the entries, and, more importantly, makes them invariant under runtime relocation (e.g., for KASLR) Acked-by: Bjorn Helgaas Signed-off-by: Ard Biesheuvel --- drivers/pci/quirks.c | 13 ++++++++++--- include/linux/pci.h | 20 ++++++++++++++++++++ 2 files changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 10684b17d0bd..b6d51b4d5ce1 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3556,9 +3556,16 @@ static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f, f->vendor == (u16) PCI_ANY_ID) && (f->device == dev->device || f->device == (u16) PCI_ANY_ID)) { - calltime = fixup_debug_start(dev, f->hook); - f->hook(dev); - fixup_debug_report(dev, calltime, f->hook); + void (*hook)(struct pci_dev *dev); +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + hook = (void *)((unsigned long)&f->hook_offset + + f->hook_offset); +#else + hook = f->hook; +#endif + calltime = fixup_debug_start(dev, hook); + hook(dev); + fixup_debug_report(dev, calltime, hook); } } diff --git a/include/linux/pci.h b/include/linux/pci.h index c170c9250c8b..e8c34afb5d4a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1792,7 +1792,11 @@ struct pci_fixup { u16 device; /* You can use PCI_ANY_ID here of course */ u32 class; /* You can use PCI_ANY_ID here too */ unsigned int class_shift; /* should be 0, 8, 16 */ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + signed int hook_offset; +#else void (*hook)(struct pci_dev *dev); +#endif }; enum pci_fixup_pass { @@ -1806,12 +1810,28 @@ enum pci_fixup_pass { pci_fixup_suspend_late, /* pci_device_suspend_late() */ }; +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS +#define __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ + class_shift, hook) \ + __ADDRESSABLE(hook) \ + asm(".section " #sec ", \"a\" \n" \ + ".balign 16 \n" \ + ".short " #vendor ", " #device " \n" \ + ".long " #class ", " #class_shift " \n" \ + ".long " VMLINUX_SYMBOL_STR(hook) " - . \n" \ + ".previous \n"); +#define DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ + class_shift, hook) \ + __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ + class_shift, hook) +#else /* Anonymous variables would be nice... */ #define DECLARE_PCI_FIXUP_SECTION(section, name, vendor, device, class, \ class_shift, hook) \ static const struct pci_fixup __PASTE(__pci_fixup_##name,__LINE__) __used \ __attribute__((__section__(#section), aligned((sizeof(void *))))) \ = { vendor, device, class, class_shift, hook }; +#endif #define DECLARE_PCI_FIXUP_CLASS_EARLY(vendor, device, class, \ class_shift, hook) \ -- 2.11.0