From: Zhenyu Ye <yezhenyu2@huawei.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, <aneesh.kumar@linux.ibm.com>,
Marc Zyngier <maz@kernel.org>, <steven.price@arm.com>,
Peter Zijlstra <peterz@infradead.org>
Cc: <linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <linux-arch@vger.kernel.org>,
<linux-mm@kvack.org>, Xiexiangyou <xiexiangyou@huawei.com>,
<liushixin2@huawei.com>, huyaqin <huyaqin1@huawei.com>,
<zhurui3@huawei.com>, <yezhenyu2@huawei.com>
Subject: [PATCH v1] arm64: tlb: fix the TTL value of tlb_get_level
Date: Wed, 23 Jun 2021 15:05:22 +0800 [thread overview]
Message-ID: <b80ead47-1f88-3a00-18e1-cacc22f54cc4@huawei.com> (raw)
The TTL field indicates the level of page table walk holding the *leaf*
entry for the address being invalidated. But currently, the TTL field
may be set to an incorrent value in the following stack:
pte_free_tlb
__pte_free_tlb
tlb_remove_table
tlb_table_invalidate
tlb_flush_mmu_tlbonly
tlb_flush
In this case, we just want to flush a PTE page, but the tlb->cleared_pmds
is set and we get tlb_level = 2 in the tlb_get_level() function. This may
cause some unexpected problems.
This patch set the TTL field to 0 if tlb->freed_tables is set. The
tlb->freed_tables indicates page table pages are freed, not the leaf
entry.
Fixes: c4ab2cbc1d87 ("arm64: tlb: Set the TTL field in flush_tlb_range")
Reported-by: ZhuRui <zhurui3@huawei.com>
Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
---
arch/arm64/include/asm/tlb.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 61c97d3b58c7..c995d1f4594f 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -28,6 +28,10 @@ static void tlb_flush(struct mmu_gather *tlb);
*/
static inline int tlb_get_level(struct mmu_gather *tlb)
{
+ /* The TTL field is only valid for the leaf entry. */
+ if (tlb->freed_tables)
+ return 0;
+
if (tlb->cleared_ptes && !(tlb->cleared_pmds ||
tlb->cleared_puds ||
tlb->cleared_p4ds))
--
2.26.2
next reply other threads:[~2021-06-23 7:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 7:05 Zhenyu Ye [this message]
2021-06-23 11:04 ` [PATCH v1] arm64: tlb: fix the TTL value of tlb_get_level Will Deacon
2021-06-23 11:28 ` Catalin Marinas
2021-06-24 1:55 ` Zhenyu Ye
2021-06-24 8:29 ` Will Deacon
2021-06-23 14:00 ` Will Deacon
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