From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Yu Zhao <yuzhao@google.com>,
Minchan Kim <minchan@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Subject: [PATCH 4.14 10/50] arm64: pgtable: Fix pte_accessible()
Date: Tue, 1 Dec 2020 09:53:09 +0100 [thread overview]
Message-ID: <20201201084646.164174753@linuxfoundation.org> (raw)
In-Reply-To: <20201201084644.803812112@linuxfoundation.org>
From: Will Deacon <will@kernel.org>
commit 07509e10dcc77627f8b6a57381e878fe269958d3 upstream.
pte_accessible() is used by ptep_clear_flush() to figure out whether TLB
invalidation is necessary when unmapping pages for reclaim. Although our
implementation is correct according to the architecture, returning true
only for valid, young ptes in the absence of racing page-table
modifications, this is in fact flawed due to lazy invalidation of old
ptes in ptep_clear_flush_young() where we elide the expensive DSB
instruction for completing the TLB invalidation.
Rather than penalise the aging path, adjust pte_accessible() to return
true for any valid pte, even if the access flag is cleared.
Cc: <stable@vger.kernel.org>
Fixes: 76c714be0e5e ("arm64: pgtable: implement pte_accessible()")
Reported-by: Yu Zhao <yuzhao@google.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20201120143557.6715-2-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/include/asm/pgtable.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -92,8 +92,6 @@ extern unsigned long empty_zero_page[PAG
#define pte_valid(pte) (!!(pte_val(pte) & PTE_VALID))
#define pte_valid_not_user(pte) \
((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
-#define pte_valid_young(pte) \
- ((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
#define pte_valid_user(pte) \
((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
@@ -101,9 +99,12 @@ extern unsigned long empty_zero_page[PAG
* Could the pte be present in the TLB? We must check mm_tlb_flush_pending
* so that we don't erroneously return false for pages that have been
* remapped as PROT_NONE but are yet to be flushed from the TLB.
+ * Note that we can't make any assumptions based on the state of the access
+ * flag, since ptep_clear_flush_young() elides a DSB when invalidating the
+ * TLB.
*/
#define pte_accessible(mm, pte) \
- (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
+ (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
/*
* p??_access_permitted() is true for valid user mappings (subject to the
next prev parent reply other threads:[~2020-12-01 8:57 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 8:52 [PATCH 4.14 00/50] 4.14.210-rc1 review Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 01/50] perf event: Check ref_reloc_sym before using it Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 02/50] mm/userfaultfd: do not access vma->vm_mm after calling handle_userfault() Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 03/50] btrfs: fix lockdep splat when reading qgroup config on mount Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 04/50] wireless: Use linux/stddef.h instead of stddef.h Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 05/50] PCI: Add device even if driver attach failed Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 06/50] btrfs: tree-checker: Enhance chunk checker to validate chunk profile Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 07/50] btrfs: adjust return values of btrfs_inode_by_name Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 08/50] btrfs: inode: Verify inode mode to avoid NULL pointer dereference Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 09/50] KVM: x86: Fix split-irqchip vs interrupt injection window request Greg Kroah-Hartman
2020-12-01 8:53 ` Greg Kroah-Hartman [this message]
2020-12-01 8:53 ` [PATCH 4.14 11/50] arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect() Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 12/50] ALSA: hda/hdmi: Use single mutex unlock in error paths Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 13/50] ALSA: hda/hdmi: fix incorrect locking in hdmi_pcm_close Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 14/50] HID: cypress: Support Varmilo Keyboards media hotkeys Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 15/50] Input: i8042 - allow insmod to succeed on devices without an i8042 controller Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 16/50] HID: hid-sensor-hub: Fix issue with devices with no report ID Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 17/50] dmaengine: xilinx_dma: use readl_poll_timeout_atomic variant Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 18/50] x86/xen: dont unbind uninitialized lock_kicker_irq Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 19/50] HID: Add Logitech Dinovo Edge battery quirk Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 20/50] proc: dont allow async path resolution of /proc/self components Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 21/50] nvme: free sq/cq dbbuf pointers when dbbuf set fails Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 22/50] dmaengine: pl330: _prep_dma_memcpy: Fix wrong burst size Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 23/50] scsi: libiscsi: Fix NOP race condition Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 24/50] scsi: target: iscsi: Fix cmd abort fabric stop race Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 25/50] perf/x86: fix sysfs type mismatches Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 26/50] phy: tegra: xusb: Fix dangling pointer on probe failure Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 27/50] batman-adv: set .owner to THIS_MODULE Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 28/50] scsi: ufs: Fix race between shutdown and runtime resume flow Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 29/50] bnxt_en: fix error return code in bnxt_init_one() Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 30/50] bnxt_en: fix error return code in bnxt_init_board() Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 31/50] video: hyperv_fb: Fix the cache type when mapping the VRAM Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 32/50] bnxt_en: Release PCI regions when DMA mask setup fails during probe Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 33/50] IB/mthca: fix return value of error branch in mthca_init_cq() Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 34/50] nfc: s3fwrn5: use signed integer for parsing GPIO numbers Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 35/50] net: ena: set initial DMA width to avoid intel iommu issue Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 36/50] ibmvnic: fix NULL pointer dereference in reset_sub_crq_queues Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 37/50] ibmvnic: fix NULL pointer dereference in ibmvic_reset_crq Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 38/50] efivarfs: revert "fix memory leak in efivarfs_create()" Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 39/50] can: gs_usb: fix endianess problem with candleLight firmware Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 40/50] platform/x86: toshiba_acpi: Fix the wrong variable assignment Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 41/50] can: m_can: fix nominal bitiming tseg2 min for version >= 3.1 Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 42/50] perf probe: Fix to die_entrypc() returns error correctly Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 43/50] USB: core: Change %pK for __user pointers to %px Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 44/50] usb: gadget: f_midi: Fix memleak in f_midi_alloc Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 45/50] usb: gadget: Fix memleak in gadgetfs_fill_super Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 46/50] x86/speculation: Fix prctl() when spectre_v2_user={seccomp,prctl},ibpb Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 47/50] x86/resctrl: Remove superfluous kernfs_get() calls to prevent refcount leak Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 48/50] x86/resctrl: Add necessary kernfs_put() " Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 49/50] USB: core: add endpoint-blacklist quirk Greg Kroah-Hartman
2020-12-01 8:53 ` [PATCH 4.14 50/50] USB: core: Fix regression in Hercules audio card Greg Kroah-Hartman
2020-12-01 21:39 ` [PATCH 4.14 00/50] 4.14.210-rc1 review Guenter Roeck
2020-12-02 6:04 ` Naresh Kamboju
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