* FAILED: patch "[PATCH] iommu: Avoid more races around device probe" failed to apply to 6.1-stable tree
@ 2023-12-03 13:37 gregkh
2023-12-05 15:01 ` [PATCH 6.1.y] iommu: Avoid more races around device probe Robin Murphy
0 siblings, 1 reply; 2+ messages in thread
From: gregkh @ 2023-12-03 13:37 UTC (permalink / raw)
To: robin.murphy, andre.draszik, gregkh, jroedel, quic_zhenhuah; +Cc: stable
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x a2e7e59a94269484a83386972ca07c22fd188854
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023120303-purposely-museum-96a7@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
a2e7e59a9426 ("iommu: Avoid more races around device probe")
fa0828036488 ("iommu: Split iommu_group_add_device()")
14891af3799e ("iommu: Move the iommu driver sysfs setup into iommu_init/deinit_device()")
aa0958570f24 ("iommu: Add iommu_init/deinit_device() paired functions")
df15d76dcaca ("iommu: Simplify the __iommu_group_remove_device() flow")
7bdb99622f7e ("iommu: Inline iommu_group_get_for_dev() into __iommu_probe_device()")
5665d15d3cb7 ("iommu: Use iommu_group_ref_get/put() for dev->iommu_group")
6eb4da8cf545 ("iommu: Have __iommu_probe_device() check for already probed devices")
0046a4337eae ("iommu: Remove iommu_group_do_dma_first_attach() from iommu_group_add_device()")
d257344c6619 ("iommu: Replace __iommu_group_dma_first_attach() with set_domain")
dcf40ed3a20d ("iommu: Make __iommu_group_set_domain() handle error unwind")
3006b15b364a ("iommu: Add for_each_group_device()")
dba9ca9d41f5 ("iommu: Same critical region for device release and removal")
293f2564f3dd ("iommu: Split iommu_group_remove_device() into helpers")
143c7bc6496c ("Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a2e7e59a94269484a83386972ca07c22fd188854 Mon Sep 17 00:00:00 2001
From: Robin Murphy <robin.murphy@arm.com>
Date: Wed, 15 Nov 2023 18:25:44 +0000
Subject: [PATCH] iommu: Avoid more races around device probe
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
It turns out there are more subtle races beyond just the main part of
__iommu_probe_device() itself running in parallel - the dev_iommu_free()
on the way out of an unsuccessful probe can still manage to trip up
concurrent accesses to a device's fwspec. Thus, extend the scope of
iommu_probe_device_lock() to also serialise fwspec creation and initial
retrieval.
Reported-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Link: https://lore.kernel.org/linux-iommu/e2e20e1c-6450-4ac5-9804-b0000acdf7de@quicinc.com/
Fixes: 01657bc14a39 ("iommu: Avoid races around device probe")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: André Draszik <andre.draszik@linaro.org>
Tested-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/16f433658661d7cadfea51e7c65da95826112a2b.1700071477.git.robin.murphy@arm.com
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index fa5dd71a80fa..02bb2cce423f 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1568,17 +1568,22 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
int err;
const struct iommu_ops *ops;
+ /* Serialise to make dev->iommu stable under our potential fwspec */
+ mutex_lock(&iommu_probe_device_lock);
/*
* If we already translated the fwspec there is nothing left to do,
* return the iommu_ops.
*/
ops = acpi_iommu_fwspec_ops(dev);
- if (ops)
+ if (ops) {
+ mutex_unlock(&iommu_probe_device_lock);
return ops;
+ }
err = iort_iommu_configure_id(dev, id_in);
if (err && err != -EPROBE_DEFER)
err = viot_iommu_configure(dev);
+ mutex_unlock(&iommu_probe_device_lock);
/*
* If we have reason to believe the IOMMU driver missed the initial
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c9a05bb49bfa..33e2a9b5d339 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -485,11 +485,12 @@ static void iommu_deinit_device(struct device *dev)
dev_iommu_free(dev);
}
+DEFINE_MUTEX(iommu_probe_device_lock);
+
static int __iommu_probe_device(struct device *dev, struct list_head *group_list)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
struct iommu_group *group;
- static DEFINE_MUTEX(iommu_probe_device_lock);
struct group_device *gdev;
int ret;
@@ -502,17 +503,15 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
* probably be able to use device_lock() here to minimise the scope,
* but for now enforcing a simple global ordering is fine.
*/
- mutex_lock(&iommu_probe_device_lock);
+ lockdep_assert_held(&iommu_probe_device_lock);
/* Device is probed already if in a group */
- if (dev->iommu_group) {
- ret = 0;
- goto out_unlock;
- }
+ if (dev->iommu_group)
+ return 0;
ret = iommu_init_device(dev, ops);
if (ret)
- goto out_unlock;
+ return ret;
group = dev->iommu_group;
gdev = iommu_group_alloc_device(group, dev);
@@ -548,7 +547,6 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
list_add_tail(&group->entry, group_list);
}
mutex_unlock(&group->mutex);
- mutex_unlock(&iommu_probe_device_lock);
if (dev_is_pci(dev))
iommu_dma_set_pci_32bit_workaround(dev);
@@ -562,8 +560,6 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
iommu_deinit_device(dev);
mutex_unlock(&group->mutex);
iommu_group_put(group);
-out_unlock:
- mutex_unlock(&iommu_probe_device_lock);
return ret;
}
@@ -573,7 +569,9 @@ int iommu_probe_device(struct device *dev)
const struct iommu_ops *ops;
int ret;
+ mutex_lock(&iommu_probe_device_lock);
ret = __iommu_probe_device(dev, NULL);
+ mutex_unlock(&iommu_probe_device_lock);
if (ret)
return ret;
@@ -1822,7 +1820,9 @@ static int probe_iommu_group(struct device *dev, void *data)
struct list_head *group_list = data;
int ret;
+ mutex_lock(&iommu_probe_device_lock);
ret = __iommu_probe_device(dev, group_list);
+ mutex_unlock(&iommu_probe_device_lock);
if (ret == -ENODEV)
ret = 0;
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 157b286e36bf..c25b4ae6aeee 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -112,16 +112,20 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
const u32 *id)
{
const struct iommu_ops *ops = NULL;
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct iommu_fwspec *fwspec;
int err = NO_IOMMU;
if (!master_np)
return NULL;
+ /* Serialise to make dev->iommu stable under our potential fwspec */
+ mutex_lock(&iommu_probe_device_lock);
+ fwspec = dev_iommu_fwspec_get(dev);
if (fwspec) {
- if (fwspec->ops)
+ if (fwspec->ops) {
+ mutex_unlock(&iommu_probe_device_lock);
return fwspec->ops;
-
+ }
/* In the deferred case, start again from scratch */
iommu_fwspec_free(dev);
}
@@ -155,6 +159,8 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
fwspec = dev_iommu_fwspec_get(dev);
ops = fwspec->ops;
}
+ mutex_unlock(&iommu_probe_device_lock);
+
/*
* If we have reason to believe the IOMMU driver missed the initial
* probe for dev, replay it to get things in order.
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ec289c1016f5..6291aa7b079b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -845,6 +845,7 @@ static inline void dev_iommu_priv_set(struct device *dev, void *priv)
dev->iommu->priv = priv;
}
+extern struct mutex iommu_probe_device_lock;
int iommu_probe_device(struct device *dev);
int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 6.1.y] iommu: Avoid more races around device probe
2023-12-03 13:37 FAILED: patch "[PATCH] iommu: Avoid more races around device probe" failed to apply to 6.1-stable tree gregkh
@ 2023-12-05 15:01 ` Robin Murphy
0 siblings, 0 replies; 2+ messages in thread
From: Robin Murphy @ 2023-12-05 15:01 UTC (permalink / raw)
To: stable; +Cc: Zhenhua Huang, Greg Kroah-Hartman, André Draszik,
Joerg Roedel
It turns out there are more subtle races beyond just the main part of
__iommu_probe_device() itself running in parallel - the dev_iommu_free()
on the way out of an unsuccessful probe can still manage to trip up
concurrent accesses to a device's fwspec. Thus, extend the scope of
iommu_probe_device_lock() to also serialise fwspec creation and initial
retrieval.
Reported-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Link: https://lore.kernel.org/linux-iommu/e2e20e1c-6450-4ac5-9804-b0000acdf7de@quicinc.com/
Fixes: 01657bc14a39 ("iommu: Avoid races around device probe")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: André Draszik <andre.draszik@linaro.org>
Tested-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/16f433658661d7cadfea51e7c65da95826112a2b.1700071477.git.robin.murphy@arm.com
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
(cherry picked from commit a2e7e59a94269484a83386972ca07c22fd188854)
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/acpi/scan.c | 7 ++++++-
drivers/iommu/iommu.c | 19 +++++++++----------
drivers/iommu/of_iommu.c | 12 +++++++++---
include/linux/iommu.h | 1 +
4 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index a0e347f6f97e..94154a849a3e 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1563,17 +1563,22 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
int err;
const struct iommu_ops *ops;
+ /* Serialise to make dev->iommu stable under our potential fwspec */
+ mutex_lock(&iommu_probe_device_lock);
/*
* If we already translated the fwspec there is nothing left to do,
* return the iommu_ops.
*/
ops = acpi_iommu_fwspec_ops(dev);
- if (ops)
+ if (ops) {
+ mutex_unlock(&iommu_probe_device_lock);
return ops;
+ }
err = iort_iommu_configure_id(dev, id_in);
if (err && err != -EPROBE_DEFER)
err = viot_iommu_configure(dev);
+ mutex_unlock(&iommu_probe_device_lock);
/*
* If we have reason to believe the IOMMU driver missed the initial
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 2bcd1f23d07d..8b3897239477 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -278,12 +278,13 @@ static void dev_iommu_free(struct device *dev)
kfree(param);
}
+DEFINE_MUTEX(iommu_probe_device_lock);
+
static int __iommu_probe_device(struct device *dev, struct list_head *group_list)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
struct iommu_device *iommu_dev;
struct iommu_group *group;
- static DEFINE_MUTEX(iommu_probe_device_lock);
int ret;
if (!ops)
@@ -295,11 +296,9 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
* probably be able to use device_lock() here to minimise the scope,
* but for now enforcing a simple global ordering is fine.
*/
- mutex_lock(&iommu_probe_device_lock);
- if (!dev_iommu_get(dev)) {
- ret = -ENOMEM;
- goto err_unlock;
- }
+ lockdep_assert_held(&iommu_probe_device_lock);
+ if (!dev_iommu_get(dev))
+ return -ENOMEM;
if (!try_module_get(ops->owner)) {
ret = -EINVAL;
@@ -326,7 +325,6 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
mutex_unlock(&group->mutex);
iommu_group_put(group);
- mutex_unlock(&iommu_probe_device_lock);
iommu_device_link(iommu_dev, dev);
return 0;
@@ -341,9 +339,6 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
err_free:
dev_iommu_free(dev);
-err_unlock:
- mutex_unlock(&iommu_probe_device_lock);
-
return ret;
}
@@ -353,7 +348,9 @@ int iommu_probe_device(struct device *dev)
struct iommu_group *group;
int ret;
+ mutex_lock(&iommu_probe_device_lock);
ret = __iommu_probe_device(dev, NULL);
+ mutex_unlock(&iommu_probe_device_lock);
if (ret)
goto err_out;
@@ -1684,7 +1681,9 @@ static int probe_iommu_group(struct device *dev, void *data)
return 0;
}
+ mutex_lock(&iommu_probe_device_lock);
ret = __iommu_probe_device(dev, group_list);
+ mutex_unlock(&iommu_probe_device_lock);
if (ret == -ENODEV)
ret = 0;
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 5696314ae69e..1fa1db3be852 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -112,16 +112,20 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
const u32 *id)
{
const struct iommu_ops *ops = NULL;
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct iommu_fwspec *fwspec;
int err = NO_IOMMU;
if (!master_np)
return NULL;
+ /* Serialise to make dev->iommu stable under our potential fwspec */
+ mutex_lock(&iommu_probe_device_lock);
+ fwspec = dev_iommu_fwspec_get(dev);
if (fwspec) {
- if (fwspec->ops)
+ if (fwspec->ops) {
+ mutex_unlock(&iommu_probe_device_lock);
return fwspec->ops;
-
+ }
/* In the deferred case, start again from scratch */
iommu_fwspec_free(dev);
}
@@ -155,6 +159,8 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
fwspec = dev_iommu_fwspec_get(dev);
ops = fwspec->ops;
}
+ mutex_unlock(&iommu_probe_device_lock);
+
/*
* If we have reason to believe the IOMMU driver missed the initial
* probe for dev, replay it to get things in order.
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 3c9da1f8979e..9d87090953bc 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -657,6 +657,7 @@ static inline void dev_iommu_priv_set(struct device *dev, void *priv)
dev->iommu->priv = priv;
}
+extern struct mutex iommu_probe_device_lock;
int iommu_probe_device(struct device *dev);
void iommu_release_device(struct device *dev);
--
2.39.2.101.g768bb238c484.dirty
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2023-12-03 13:37 FAILED: patch "[PATCH] iommu: Avoid more races around device probe" failed to apply to 6.1-stable tree gregkh
2023-12-05 15:01 ` [PATCH 6.1.y] iommu: Avoid more races around device probe Robin Murphy
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