[PATCH 3.19.y-ckt 42/54] x86/sysfb_efi: Fix valid BAR address range check

From	Kamal Mostafa <kamal@canonical.com>
Newsgroups	linux.kernel
Subject	[PATCH 3.19.y-ckt 42/54] x86/sysfb_efi: Fix valid BAR address range check
Date	2016-05-10 02:10 +0200
Message-ID	<rx3pp-81T-31@gated-at.bofh.it> (permalink)
References	<rx3pn-81T-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.19.8-ckt21 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Wang YanQing <udknight@gmail.com>

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 <udknight@gmail.com>
[ Rewrote changelog. ]
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Peter Jones <pjones@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
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 <mingo@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 arch/x86/kernel/sysfb_efi.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/sysfb_efi.c b/arch/x86/kernel/sysfb_efi.c
index b285d4e..5da924b 100644
--- 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 struct dmi_system_id *id)
 					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;
 					}
 				}
 			}
-- 
2.7.4

Thread

[3.19.y-ckt stable] Linux 3.19.8-ckt21 stable review Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 42/54] x86/sysfb_efi: Fix valid BAR address range check Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 53/54] cxgbi: fix uninitialized flowi6 Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 14/54] mm: split ET_DYN ASLR from mmap ASLR Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 51/54] batman-adv: Reduce refcnt of removed router when updating route Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 18/54] ASoC: dapm: Make sure we have a card when displaying component widgets Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 11/54] s390: standardize mmap_rnd() usage Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 04/54] arm: factor out mmap ASLR into mmap_rnd Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 52/54] batman-adv: Fix broadcast/ogm queue limit on a removed interface Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 31/54] ARM: SoCFPGA: Fix secondary CPU startup in thumb2 kernel Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 48/54] jme: Do not enable NIC WoL functions on S0 Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 54/54] net/mlx4_en: fix spurious timestamping callbacks Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 12/54] mm: expose arch_mmap_rnd when available Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:10 +0200
  [PATCH 3.19.y-ckt 20/54] i2c: cpm: Fix build break due to incompatible pointer types Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 21/54] i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 37/54] Minimal fix-up of bad hashing behavior of hash_64() Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 36/54] powerpc: Fix bad inline asm constraint in create_zero_mask() Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 32/54] IB/security: Restrict use of the write() interface Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 24/54] USB: serial: cp210x: add Straizona Focusers device ids Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 09/54] s390: avoid z13 cache aliasing Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 34/54] mm: vmscan: reclaim highmem zone if buffer_heads is over limit Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 28/54] cxl: Keep IRQ mappings on context teardown Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 26/54] workqueue: fix ghost PENDING flag while doing MQ IO Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 27/54] drm/dp/mst: Get validated port ref in drm_dp_update_payload_part1() Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 29/54] drm/i915: Fix system resume if PCI device remained enabled Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 08/54] powerpc: standardize mmap_rnd() usage Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 40/54] MAINTAINERS: Remove asterisk from EFI directory names Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 41/54] ACPICA: Dispatcher: Update thread ID for recursive method calls Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 47/54] parisc: fix a bug when syscall number of tracee is __NR_Linux_syscalls Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 25/54] ALSA: hda - Add dock support for ThinkPad X260 Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 23/54] USB: serial: cp210x: add ID for Link ECU Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 13/54] s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 30/54] drm/i915/ddi: Fix eDP VDD handling during booting and suspend/resume Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 35/54] EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 06/54] arm64: standardize mmap_rnd() usage Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 43/54] fs/pnode.c: treat zero mnt_group_id-s as unequal Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 44/54] propogate_mnt: Handle the first propogated copy being a slave Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 33/54] mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 10/54] s390/mm: align 64-bit PIE binaries to 4GB Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 17/54] ASoC: rt5640: Correct the digital interface data select Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 46/54] x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 39/54] drm/radeon: make sure vertical front porch is at least 1 Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 19/54] iio: ak8975: Fix NULL pointer exception on early interrupt Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:20 +0200
  [PATCH 3.19.y-ckt 07/54] mips: extract logic for mmap_rnd() Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:30 +0200
  [PATCH 3.19.y-ckt 01/54] [3.19-stable-only] Revert "powerpc: Update TM user feature bits in scan_features()" Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:30 +0200
    Re: [PATCH 3.19.y-ckt 01/54] [3.19-stable-only] Revert "powerpc:  Update TM user feature bits in scan_features()" Michael Ellerman <mpe@ellerman.id.au> - 2016-05-10 03:50 +0200
  [PATCH 3.19.y-ckt 02/54] [3.19-stable-only] fix backport "KVM: s390: avoid memory overwrites on emergency signal injection" Kamal Mostafa <kamal@canonical.com> - 2016-05-10 02:30 +0200

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