commit 229e6ee43d2a160a1592b83aad620d6027084aad upstream.
Null pointer dereference occurs due to a race between smmu
driver probe and client driver probe, when of_dma_configure()
for client is called after the iommu_device_register() for smmu driver
probe has executed but before the driver_bound() for smmu driver
has been called.
Following is how the race occurs:
T1:Smmu device probe T2: Client device probe
really_probe()
arm_smmu_device_probe()
iommu_device_register()
really_probe()
platform_dma_configure()
of_dma_configure()
of_dma_configure_id()
of_iommu_configure()
iommu_probe_device()
iommu_init_device()
arm_smmu_probe_device()
arm_smmu_get_by_fwnode()
driver_find_device_by_fwnode()
driver_find_device()
next_device()
klist_next()
/* null ptr
assigned to smmu */
/* null ptr dereference
while smmu->streamid_mask */
driver_bound()
klist_add_tail()
When this null smmu pointer is dereferenced later in
arm_smmu_probe_device, the device crashes.
Fix this by deferring the probe of the client device
until the smmu device has bound to the arm smmu driver.
Fixes: 021bb8420d44 ("iommu/arm-smmu: Wire up generic configuration support")
Cc: stable@vger.kernel.org
Co-developed-by: Prakash Gupta <quic_guptap@quicinc.com>
Signed-off-by: Prakash Gupta <quic_guptap@quicinc.com>
Signed-off-by: Pratyush Brahma <quic_pbrahma@quicinc.com>
Link: https://lore.kernel.org/r/20241004090428.2035-1-quic_pbrahma@quicinc.com
[will: Add comment]
Signed-off-by: Will Deacon <will@kernel.org>
[rm: backport for context conflict prior to 6.8]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3a8990b8a778219327c5f8ecf10b5d81377b925a ]
On qcom msm8998, writing to the last context bank of lpass_q6_smmu
(base address 0x05100000) produces a system freeze & reboot.
The hardware/hypervisor reports 13 context banks for the LPASS SMMU
on msm8998, but only the first 12 are accessible...
Override the number of context banks
[ 2.546101] arm-smmu 5100000.iommu: probing hardware configuration...
[ 2.552439] arm-smmu 5100000.iommu: SMMUv2 with:
[ 2.558945] arm-smmu 5100000.iommu: stage 1 translation
[ 2.563627] arm-smmu 5100000.iommu: address translation ops
[ 2.568923] arm-smmu 5100000.iommu: non-coherent table walk
[ 2.574566] arm-smmu 5100000.iommu: (IDR0.CTTW overridden by FW configuration)
[ 2.580220] arm-smmu 5100000.iommu: stream matching with 12 register groups
[ 2.587263] arm-smmu 5100000.iommu: 13 context banks (0 stage-2 only)
[ 2.614447] arm-smmu 5100000.iommu: Supported page sizes: 0x63315000
[ 2.621358] arm-smmu 5100000.iommu: Stage-1: 36-bit VA -> 36-bit IPA
[ 2.627772] arm-smmu 5100000.iommu: preserved 0 boot mappings
Specifically, the crashes occur here:
qsmmu->bypass_cbndx = smmu->num_context_banks - 1;
arm_smmu_cb_write(smmu, qsmmu->bypass_cbndx, ARM_SMMU_CB_SCTLR, 0);
and here:
arm_smmu_write_context_bank(smmu, i);
arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_FSR, ARM_SMMU_CB_FSR_FAULT);
It is likely that FW reserves the last context bank for its own use,
thus a simple work-around is: DON'T USE IT in Linux.
If we decrease the number of context banks, last one will be "hidden".
Signed-off-by: Marc Gonzalez <mgonzalez@freebox.fr>
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20240820-smmu-v3-1-2f71483b00ec@freebox.fr
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 80fea979dd9d48d67c5b48d2f690c5da3e543ebd ]
If devm_add_action() returns -ENOMEM, then MSIs are allocated but not
not freed on teardown. Use devm_add_action_or_reset() instead to keep
the static analyser happy.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Aleksandr Aprelkov <aaprelkov@usergate.com>
Link: https://lore.kernel.org/r/20240403053759.643164-1-aaprelkov@usergate.com
[will: Tweak commit message, remove warning message]
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit afc95681c3068956fed1241a1ff1612c066c75ac upstream.
In some cases the firmware expects cbndx 1 to be assigned to the GMU,
so we also want the default domain for the GMU to be an identy domain.
This way it does not get a context bank assigned. Without this, both
of_dma_configure() and drm/msm's iommu_domain_attach() will trigger
allocating and configuring a context bank. So GMU ends up attached to
both cbndx 1 and later cbndx 2. This arrangement seemingly confounds
and surprises the firmware if the GPU later triggers a translation
fault, resulting (on sc8280xp / lenovo x13s, at least) in the SMMU
getting wedged and the GPU stuck without memory access.
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20231210180655.75542-1-robdclark@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
