linux-kernel - [PATCH] iommu/amd: Don't initialize IOMMUv2 resources when not required

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Thu, 15 Mar 2012 12:49:21 +0100
From:	Joerg Roedel <joerg.roedel@....com>
To:	<iommu@...ts.linux-foundation.org>, <linux-kernel@...r.kernel.org>
CC:	Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH] iommu/amd: Don't initialize IOMMUv2 resources when not required

Add a check to the init-path of the AMD IOMMUv2 driver if
the hardware is available in the system. Only allocate all
the resources if it is really available.

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 drivers/iommu/amd_iommu_v2.c |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 8add9f1..036fe9b 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -921,7 +921,16 @@ static int __init amd_iommu_v2_init(void)
 	size_t state_table_size;
 	int ret;
 
-	pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@....com>");
+	pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@....com>\n");
+
+	if (!amd_iommu_v2_supported()) {
+		pr_info("AMD IOMMUv2 functionality not available on this sytem\n");
+		/*
+		 * Load anyway to provide the symbols to other modules
+		 * which may use AMD IOMMUv2 optionally.
+		 */
+		return 0;
+	}
 
 	spin_lock_init(&state_lock);
 
@@ -961,6 +970,9 @@ static void __exit amd_iommu_v2_exit(void)
 	size_t state_table_size;
 	int i;
 
+	if (!amd_iommu_v2_supported())
+		return;
+
 	profile_event_unregister(PROFILE_TASK_EXIT, &profile_nb);
 	amd_iommu_unregister_ppr_notifier(&ppr_nb);
 
-- 
1.7.5.4


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/