From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42993 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750890AbcEHNBL (ORCPT ); Sun, 8 May 2016 09:01:11 -0400 Subject: Patch "x86/sysfb_efi: Fix valid BAR address range check" has been added to the 4.4-stable tree To: udknight@gmail.com, ard.biesheuvel@linaro.org, dh.herrmann@gmail.com, gregkh@linuxfoundation.org, matt@codeblueprint.co.uk, mingo@kernel.org, peterz@infradead.org, pjones@redhat.com, tglx@linutronix.de, tomi.valkeinen@ti.com, torvalds@linux-foundation.org Cc: , From: Date: Sun, 08 May 2016 15:00:56 +0200 Message-ID: <14627124568185@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/sysfb_efi: Fix valid BAR address range check to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-sysfb_efi-fix-valid-bar-address-range-check.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From c10fcb14c7afd6688c7b197a814358fecf244222 Mon Sep 17 00:00:00 2001 From: Wang YanQing Date: Thu, 5 May 2016 14:14:21 +0100 Subject: x86/sysfb_efi: Fix valid BAR address range check From: Wang YanQing commit c10fcb14c7afd6688c7b197a814358fecf244222 upstream. The code for checking whether a BAR address range is valid will break out of the loop when a start address of 0x0 is encountered. This behaviour is wrong since by breaking out of the loop we may miss the BAR that describes the EFI frame buffer in a later iteration. Because of this bug I can't use video=efifb: boot parameter to get efifb on my new ThinkPad E550 for my old linux system hard disk with 3.10 kernel. In 3.10, efifb is the only choice due to DRM/I915 not supporting the GPU. This patch also add a trivial optimization to break out after we find the frame buffer address range without testing later BARs. Signed-off-by: Wang YanQing [ Rewrote changelog. ] Signed-off-by: Matt Fleming Reviewed-by: Peter Jones Cc: Ard Biesheuvel Cc: David Herrmann Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tomi Valkeinen Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462454061-21561-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/sysfb_efi.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/sysfb_efi.c +++ b/arch/x86/kernel/sysfb_efi.c @@ -106,14 +106,24 @@ static int __init efifb_set_system(const continue; for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { resource_size_t start, end; + unsigned long flags; + + flags = pci_resource_flags(dev, i); + if (!(flags & IORESOURCE_MEM)) + continue; + + if (flags & IORESOURCE_UNSET) + continue; + + if (pci_resource_len(dev, i) == 0) + continue; start = pci_resource_start(dev, i); - if (start == 0) - break; end = pci_resource_end(dev, i); if (screen_info.lfb_base >= start && screen_info.lfb_base < end) { found_bar = 1; + break; } } } Patches currently in stable-queue which might be from udknight@gmail.com are queue-4.4/x86-sysfb_efi-fix-valid-bar-address-range-check.patch