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From: Kevin Mitchell <kevmitch@arista.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Kevin Mitchell <kevmitch@arista.com>
Subject: [PATCH 1/3] iommu/amd: make iommu_disable safer
Date: Wed, 12 Jun 2019 14:52:03 -0700	[thread overview]
Message-ID: <20190612215203.12711-2-kevmitch@arista.com> (raw)
In-Reply-To: <20190612215203.12711-1-kevmitch@arista.com>

Make it safe to call iommu_disable during early init error conditions
before mmio_base is set, but after the struct amd_iommu has been added
to the amd_iommu_list. For example, this happens if firmware fails to
fill in mmio_phys in the ACPI table leading to a NULL pointer
dereference in iommu_feature_disable.

Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
---
 drivers/iommu/amd_iommu_init.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index f773792d77fd..3798d7303c99 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -424,6 +424,9 @@ static void iommu_enable(struct amd_iommu *iommu)
 
 static void iommu_disable(struct amd_iommu *iommu)
 {
+	if (!iommu->mmio_base)
+		return;
+
 	/* Disable command buffer */
 	iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
 
-- 
2.20.1


  reply	other threads:[~2019-06-13 17:15 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-12 21:52 [PATCH 0/3] handle init errors more gracefully in amd_iommu Kevin Mitchell
2019-06-12 21:52 ` Kevin Mitchell [this message]
2019-06-12 21:52 ` [PATCH 2/3] iommu/amd: move gart fallback to amd_iommu_init Kevin Mitchell
2019-06-12 21:52 ` [PATCH 3/3] iommu/amd: only free resources once on init error Kevin Mitchell
2019-07-01 11:54 ` [PATCH 0/3] handle init errors more gracefully in amd_iommu Joerg Roedel
  -- strict thread matches above, loose matches on Subject: below --
2019-05-28 18:29 Kevin Mitchell
2019-05-28 18:29 ` [PATCH 1/3] iommu/amd: make iommu_disable safer Kevin Mitchell
2019-05-17  0:52 [PATCH 0/3] handle init errors more gracefully in amd_iommu Kevin Mitchell
2019-05-17  0:52 ` [PATCH 1/3] iommu/amd: make iommu_disable safer Kevin Mitchell
2019-05-27 13:50   ` Joerg Roedel

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