Commit c9d8b55f authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Linus Torvalds
Browse files

PCI: Add support for relative addressing in quirk tables 

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)

Link: http://lkml.kernel.org/r/20180704083651.24360-6-ard.biesheuvel@linaro.org


Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1b1eeca7

drivers/pci/quirks.c

+9 −3
Original line number Diff line number Diff line
@@ -66,9 +66,15 @@ 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 = offset_to_ptr(&f->hook_offset);

#else

			hook = f->hook;

#endif

			calltime = fixup_debug_start(dev, hook);

			hook(dev);

			fixup_debug_report(dev, calltime, hook);

		}

}

include/linux/pci.h

+20 −0
Original line number Diff line number Diff line
@@ -1809,7 +1809,11 @@ struct pci_fixup { 
	u16 device;			/* Or PCI_ANY_ID */

	u32 class;			/* Or PCI_ANY_ID */

	unsigned int class_shift;	/* should be 0, 8, 16 */

#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS

	int hook_offset;

#else

	void (*hook)(struct pci_dev *dev);

#endif

};



enum pci_fixup_pass {
@@ -1823,12 +1827,28 @@ 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 "	#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)		\

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