From: Joerg Roedel <joro@8bytes.org>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>
Subject: Re: [PATCH] iommu: Remove functions that support private domain
Date: Fri, 15 May 2020 17:46:16 +0200 [thread overview]
Message-ID: <20200515154616.GY18353@8bytes.org> (raw)
In-Reply-To: <9d65b30a-d22e-d566-d740-601f8d638bfd@linux.intel.com>
On Fri, May 15, 2020 at 08:55:42PM +0800, Lu Baolu wrote:
> It seems that we can do like this:
>
> [1] mutex_lock(&group->lock)
> [2] for_each_group_device(device_lock())
> [3] if (for_each_group_device(!device_is_bound()))
> change_default_domain()
> [4] for_each_group_device_reverse(device_unlock())
> [5] mutex_unlock(&group->lock)
The problem here is that I am pretty sure we also have:
device_lock() /* from device/driver core code */
-> bus_notifier()
-> iommu_bus_notifier()
-> ...
-> mutex_lock(&group->lock)
Which would cause lock-inversion with the above code.
Joerg
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next prev parent reply other threads:[~2020-05-15 15:46 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 22:47 [PATCH] iommu: Remove functions that support private domain Sai Praneeth Prakhya
2020-05-14 13:13 ` Joerg Roedel
2020-05-14 17:51 ` Prakhya, Sai Praneeth
2020-05-14 18:32 ` Joerg Roedel
2020-05-14 18:44 ` Prakhya, Sai Praneeth
2020-05-14 19:56 ` Joerg Roedel
2020-05-14 23:12 ` Prakhya, Sai Praneeth
2020-05-15 9:59 ` Joerg Roedel
2020-05-15 12:55 ` Lu Baolu
2020-05-15 15:46 ` Joerg Roedel [this message]
2020-05-17 8:29 ` Prakhya, Sai Praneeth
2020-05-25 13:56 ` Joerg Roedel
2020-05-28 19:31 ` Prakhya, Sai Praneeth
2020-05-15 18:35 ` Prakhya, Sai Praneeth
2020-05-15 10:01 ` Joerg Roedel
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