linux-kernel - [PATCH 8/9] iommu/amd: Don't hold a reference to task

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

Message-Id: <1404998750-15536-9-git-send-email-joro@8bytes.org>
Date:	Thu, 10 Jul 2014 15:25:49 +0200
From:	Joerg Roedel <joro@...tes.org>
To:	iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org
Cc:	Oded.Gabbay@....com, Joerg Roedel <jroedel@...e.de>
Subject: [PATCH 8/9] iommu/amd: Don't hold a reference to task_struct

From: Joerg Roedel <jroedel@...e.de>

Since we are only caring about the lifetime of the mm_struct
and not the task we can't safely keep a reference to it. The
reference is also not needed anymore, so remove that code
entirely.

Signed-off-by: Joerg Roedel <jroedel@...e.de>
Tested-by: Oded Gabbay <Oded.Gabbay@....com>
---
 drivers/iommu/amd_iommu_v2.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 2b848c0..f7ca009 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -47,7 +47,6 @@ struct pasid_state {
 	atomic_t count;				/* Reference count */
 	unsigned mmu_notifier_count;		/* Counting nested mmu_notifier
 						   calls */
-	struct task_struct *task;		/* Task bound to this PASID */
 	struct mm_struct *mm;			/* mm_struct for the faults */
 	struct mmu_notifier mn;                 /* mmu_notifier handle */
 	struct pri_queue pri[PRI_QUEUE_SIZE];	/* PRI tag states */
@@ -531,7 +530,7 @@ static void do_fault(struct work_struct *work)
 	write = !!(fault->flags & PPR_FAULT_WRITE);
 
 	down_read(&fault->state->mm->mmap_sem);
-	npages = get_user_pages(fault->state->task, fault->state->mm,
+	npages = get_user_pages(NULL, fault->state->mm,
 				fault->address, 1, write, 0, &page, NULL);
 	up_read(&fault->state->mm->mmap_sem);
 
@@ -672,7 +671,6 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
 	spin_lock_init(&pasid_state->lock);
 
 	mm                        = get_task_mm(task);
-	pasid_state->task         = task;
 	pasid_state->mm           = mm;
 	pasid_state->device_state = dev_state;
 	pasid_state->pasid        = pasid;
-- 
1.7.9.5


--
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/