* Re: [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown
2026-09-10 6:54 [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown Wentao Guan
@ 2026-09-11 11:20 ` Sasha Levin
2026-09-11 12:49 ` Shameer Kolothum Thodi
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Sasha Levin @ 2026-09-11 11:20 UTC (permalink / raw)
To: jgg
Cc: Sasha Levin, will, linux-arm-kernel, iommu, stable, linux-kernel,
nicolinc, skolothumtho, Wentao Guan
> The Tegra241 CMDQV teardown fix moved VINTF hardware deinitialization
> into the implementation device_disable() callback. However, its
> stable backport preceded the conversion to devm teardown and could
> only invoke the callback from the shutdown path.
This is a stable-only change for 7.2.y with no upstream commit to point at.
Since it has no Reviewed-by or Acked-by from an arm-smmu-v3 or tegra241-cmdqv
maintainer, we need that before queuing a stable-only fix.
Could you get a maintainer ack for this?
--
Thanks,
Sasha
^ permalink raw reply [flat|nested] 5+ messages in thread* RE: [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown
2026-09-10 6:54 [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown Wentao Guan
2026-09-11 11:20 ` Sasha Levin
@ 2026-09-11 12:49 ` Shameer Kolothum Thodi
2026-09-11 22:24 ` Nicolin Chen
2026-09-12 15:26 ` Sasha Levin
3 siblings, 0 replies; 5+ messages in thread
From: Shameer Kolothum Thodi @ 2026-09-11 12:49 UTC (permalink / raw)
To: Wentao Guan, sashal@kernel.org, Jason Gunthorpe
Cc: will@kernel.org, linux-arm-kernel@lists.infradead.org,
iommu@lists.linux.dev, stable@vger.kernel.org,
linux-kernel@vger.kernel.org, Nicolin Chen
> -----Original Message-----
> From: Wentao Guan <guanwentao@uniontech.com>
> Sent: 10 September 2026 07:54
> To: sashal@kernel.org; Jason Gunthorpe <jgg@nvidia.com>
> Cc: will@kernel.org; linux-arm-kernel@lists.infradead.org;
> iommu@lists.linux.dev; stable@vger.kernel.org; linux-kernel@vger.kernel.org;
> Nicolin Chen <nicolinc@nvidia.com>; Shameer Kolothum Thodi
> <skolothumtho@nvidia.com>; Wentao Guan <guanwentao@uniontech.com>
> Subject: [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during
> devm teardown
>
> External email: Use caution opening links or attachments
>
>
> The Tegra241 CMDQV teardown fix moved VINTF hardware deinitialization
> into the implementation device_disable() callback. However, its stable
> backport preceded the conversion to devm teardown and could only invoke
> the callback from the shutdown path.
>
> Now that arm_smmu_disable_action() manages normal teardown, invoke the
> implementation callback there while the command queue is still alive.
> This prevents the subsequent implementation remove action from releasing
> resources while the CMDQV hardware remains active.
>
> After ("iommu/arm-smmu-v3: Manage teardown with devm") merged in
> stable,
> now keep the shutdown path consistent with mainline, where disabling
> the base SMMU is sufficient.
>
> It is a fix for stable tree commit to aligned with mainline, so no
> upstream commit id here.
>
> Fixes: 5994617e09ee ("iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free
> on teardown")
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index c993e101fab3a..ea908afb0da9d 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -4789,6 +4789,8 @@ static void arm_smmu_disable_action(void *data)
> {
> struct arm_smmu_device *smmu = data;
>
> + if (smmu->impl_ops && smmu->impl_ops->device_disable)
> + smmu->impl_ops->device_disable(smmu);
> arm_smmu_device_disable(smmu);
> }
>
> @@ -5621,8 +5623,6 @@ static void arm_smmu_device_shutdown(struct
> platform_device *pdev)
> {
> struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
>
> - if (smmu->impl_ops && smmu->impl_ops->device_disable)
> - smmu->impl_ops->device_disable(smmu);
> arm_smmu_device_disable(smmu);
> }
LGTM;
Reviewed-by: Shameer Kolothum <skolothumtho@nvidia.com>
Thanks,
Shameer
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown
2026-09-10 6:54 [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown Wentao Guan
2026-09-11 11:20 ` Sasha Levin
2026-09-11 12:49 ` Shameer Kolothum Thodi
@ 2026-09-11 22:24 ` Nicolin Chen
2026-09-12 15:26 ` Sasha Levin
3 siblings, 0 replies; 5+ messages in thread
From: Nicolin Chen @ 2026-09-11 22:24 UTC (permalink / raw)
To: Wentao Guan
Cc: sashal, jgg, will, linux-arm-kernel, iommu, stable, linux-kernel,
skolothumtho
On Thu, Sep 10, 2026 at 02:54:29PM +0800, Wentao Guan wrote:
> The Tegra241 CMDQV teardown fix moved VINTF hardware deinitialization
> into the implementation device_disable() callback. However, its stable
> backport preceded the conversion to devm teardown and could only invoke
> the callback from the shutdown path.
Hmm, it did...
[correct in mainline]
git log --oneline v7.3-rc1 drivers/iommu/arm/arm-smmu-v3/
...
9ff145a25c5c8 iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown
2bd22a0d40503 iommu/arm-smmu-v3: Manage teardown with devm
...
[inverted in two trees]
git log --oneline v7.2.5 drivers/iommu/arm/arm-smmu-v3/
...
78fd5a2d65f35 iommu/arm-smmu-v3: Manage teardown with devm
f9b7375db3b36 iommu/arm-smmu-v3: Add HAFT support for SVA
5994617e09ee6 iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown
...
git log --oneline v6.18.51 drivers/iommu/arm/arm-smmu-v3/
...
2235eafda9b3d iommu/arm-smmu-v3: Manage teardown with devm
d903d99ffd22b iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field
d2ab08437e913 iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown
...
[missing cmdqv fix]
git log --oneline v6.12.109 -33 drivers/iommu/arm/arm-smmu-v3/
...
981686f413776 iommu/arm-smmu-v3: Manage teardown with devm
...
Patch itself looks good to me for v7.2 stable and v6.8 longterm.
But v6.12 longterm might need some extra fix, Sasha?
> Now that arm_smmu_disable_action() manages normal teardown, invoke the
> implementation callback there while the command queue is still alive.
> This prevents the subsequent implementation remove action from releasing
> resources while the CMDQV hardware remains active.
>
> After ("iommu/arm-smmu-v3: Manage teardown with devm") merged in stable,
> now keep the shutdown path consistent with mainline, where disabling
> the base SMMU is sufficient.
>
> It is a fix for stable tree commit to aligned with mainline, so no
> upstream commit id here.
>
> Fixes: 5994617e09ee ("iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown")
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Acked-by: Nicolin Chen <nicolinc@nvidia.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown
2026-09-10 6:54 [PATCH 7.2.y] iommu/arm-smmu-v3: Disable implementations during devm teardown Wentao Guan
` (2 preceding siblings ...)
2026-09-11 22:24 ` Nicolin Chen
@ 2026-09-12 15:26 ` Sasha Levin
3 siblings, 0 replies; 5+ messages in thread
From: Sasha Levin @ 2026-09-12 15:26 UTC (permalink / raw)
To: jgg
Cc: Sasha Levin, will, linux-arm-kernel, iommu, stable, linux-kernel,
nicolinc, skolothumtho, Wentao Guan
> Now that arm_smmu_disable_action() manages normal teardown, invoke the
> implementation callback there while the command queue is still alive.
> This prevents the subsequent implementation remove action from releasing
> resources while the CMDQV hardware remains active.
>
> Fixes: 5994617e09ee ("iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown")
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Queued for 7.2, thanks.
--
Thanks,
Sasha
^ permalink raw reply [flat|nested] 5+ messages in thread