A recent DRM series purporting to simplify support for "transparent
bridges" and handling of probe deferrals ironically exposed a
use-after-free issue on pmic_glink_altmode probe deferral.
This has manifested itself as the display subsystem occasionally failing
to initialise and NULL-pointer dereferences during boot of machines like
the Lenovo ThinkPad X13s.
Specifically, the dp-hpd bridge is currently registered before all
resources have been acquired which means that it can also be
deregistered on probe deferrals.
In the meantime there is a race window where the new aux bridge driver
(or PHY driver previously) may have looked up the dp-hpd bridge and
stored a (non-reference-counted) pointer to the bridge which is about to
be deallocated.
When the display controller is later initialised, this triggers a
use-after-free when attaching the bridges:
dp -> aux -> dp-hpd (freed)
which may, for example, result in the freed bridge failing to attach:
[drm:drm_bridge_attach [drm]] *ERROR* failed to attach bridge /soc@0/phy@88eb000 to encoder TMDS-31: -16
or a NULL-pointer dereference:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
...
Call trace:
drm_bridge_attach+0x70/0x1a8 [drm]
drm_aux_bridge_attach+0x24/0x38 [aux_bridge]
drm_bridge_attach+0x80/0x1a8 [drm]
dp_bridge_init+0xa8/0x15c [msm]
msm_dp_modeset_init+0x28/0xc4 [msm]
The DRM bridge implementation is clearly fragile and implicitly built on
the assumption that bridges may never go away. In this case, the fix is
to move the bridge registration in the pmic_glink_altmode driver to
after all resources have been looked up.
Incidentally, with the new dp-hpd bridge implementation, which registers
child devices, this is also a requirement due to a long-standing issue
in driver core that can otherwise lead to a probe deferral loop (see
commit fbc35b45f9 ("Add documentation on meaning of -EPROBE_DEFER")).
[DB: slightly fixed commit message by adding the word 'commit']
Fixes: 080b4e2485 ("soc: qcom: pmic_glink: Introduce altmode support")
Fixes: 2bcca96abf ("soc: qcom: pmic-glink: switch to DRM_AUX_HPD_BRIDGE")
Cc: <stable@vger.kernel.org> # 6.3
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240217150228.5788-4-johan+linaro@kernel.org
Combining allocation and registration is an anti-pattern that should be
avoided. Add two new functions for allocating and registering an dp-hpd
bridge with a proper 'devm' prefix so that it is clear that these are
device managed interfaces.
devm_drm_dp_hpd_bridge_alloc()
devm_drm_dp_hpd_bridge_add()
The new interface will be used to fix a use-after-free bug in the
Qualcomm PMIC GLINK driver and may prevent similar issues from being
introduced elsewhere.
The existing drm_dp_hpd_bridge_register() is reimplemented using the
above and left in place for now.
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240217150228.5788-3-johan+linaro@kernel.org
On Tegra186, secure world applications may need to access host1x
during suspend/resume, and rely on the kernel to keep Host1x out
of reset during the suspend cycle. As such, as a quirk,
skip asserting Host1x's reset on Tegra186.
We don't need to keep the clocks enabled, as BPMP ensures the clock
stays on while Host1x is being used. On newer SoC's, the reset line
is inaccessible, so there is no need for the quirk.
Fixes: b7c00cdf6d ("gpu: host1x: Enable system suspend callbacks")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222010517.1573931-1-cyndis@kapsi.fi
During syncobj_eventfd_entry_func, dma_fence_chain_find_seqno may set
the fence to NULL if the given seqno is signaled and a later seqno has
already been submitted. In that case, the eventfd should be signaled
immediately which currently does not happen.
This is a similar issue to the one addressed by commit b19926d4f3
("drm/syncobj: Deal with signalled fences in drm_syncobj_find_fence.").
As a fix, if the return value of dma_fence_chain_find_seqno indicates
success but it sets the fence to NULL, we will assign a stub fence to
ensure the following code still signals the eventfd.
v1 -> v2: assign a stub fence instead of signaling the eventfd
Signed-off-by: Erik Kurzinger <ekurzinger@nvidia.com>
Fixes: c7a4722971 ("drm/syncobj: add IOCTL to register an eventfd")
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20240221184527.37667-1-ekurzinger@nvidia.com
When waiting for a syncobj timeline point whose fence has not yet been
submitted with the WAIT_FOR_SUBMIT flag, a callback is registered using
drm_syncobj_fence_add_wait and the thread is put to sleep until the
timeout expires. If the fence is submitted before then,
drm_syncobj_add_point will wake up the sleeping thread immediately which
will proceed to wait for the fence to be signaled.
However, if the WAIT_AVAILABLE flag is used instead,
drm_syncobj_fence_add_wait won't get called, meaning the waiting thread
will always sleep for the full timeout duration, even if the fence gets
submitted earlier. If it turns out that the fence *has* been submitted
by the time it eventually wakes up, it will still indicate to userspace
that the wait completed successfully (it won't return -ETIME), but it
will have taken much longer than it should have.
To fix this, we must call drm_syncobj_fence_add_wait if *either* the
WAIT_FOR_SUBMIT flag or the WAIT_AVAILABLE flag is set. The only
difference being that with WAIT_FOR_SUBMIT we will also wait for the
fence to be signaled after it has been submitted while with
WAIT_AVAILABLE we will return immediately.
IGT test patch: https://lists.freedesktop.org/archives/igt-dev/2024-January/067537.html
v1 -> v2: adjust lockdep_assert_none_held_once condition
(cherry picked from commit 8c44ea8163)
Fixes: 01d6c35783 ("drm/syncobj: add support for timeline point wait v8")
Signed-off-by: Erik Kurzinger <ekurzinger@nvidia.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20240119163208.3723457-1-ekurzinger@nvidia.com
clang-16 warns about casting between incompatible function types:
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadow.c:161:10: error: cast from 'void (*)(const struct firmware *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]
161 | .fini = (void(*)(void *))release_firmware,
This one was done to use the generic shadow_fw_release() function as a
callback for struct nvbios_source. Change it to use the same prototype
as the other five instances, with a trivial helper function that actually
calls release_firmware.
Fixes: 70c0f263cc ("drm/nouveau/bios: pull in basic vbios subdev, more to come later")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240213095753.455062-1-arnd@kernel.org
The conversion to kvcalloc() mixed up the object size and count
arguments, causing a warning:
drivers/gpu/drm/nouveau/nouveau_svm.c: In function 'nouveau_svm_fault_buffer_ctor':
drivers/gpu/drm/nouveau/nouveau_svm.c:1010:40: error: 'kvcalloc' sizes specified with 'sizeof' in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
1010 | buffer->fault = kvcalloc(sizeof(*buffer->fault), buffer->entries, GFP_KERNEL);
| ^
drivers/gpu/drm/nouveau/nouveau_svm.c:1010:40: note: earlier argument should specify number of elements, later size of each element
The behavior is still correct aside from the warning, but fixing it avoids
the warnings and can help the compiler track the individual objects better.
Fixes: 71e4bbca07 ("nouveau/svm: Use kvcalloc() instead of kvzalloc()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240212112230.1117284-1-arnd@kernel.org
nouveau_abi16_ioctl_channel_alloc() and nouveau_cli_init() simply call
their corresponding *_fini() counterpart. This can lead to
nouveau_sched_fini() being called without struct nouveau_sched ever
being initialized in the first place.
Instead of embedding struct nouveau_sched into struct nouveau_cli and
struct nouveau_chan_abi16, allocate struct nouveau_sched separately,
such that we can check for the corresponding pointer to be NULL in the
particular *_fini() functions.
It makes sense to allocate struct nouveau_sched separately anyway, since
in a subsequent commit we can also avoid to allocate a struct
nouveau_sched in nouveau_abi16_ioctl_channel_alloc() at all, if the
VM_BIND uAPI has been disabled due to the legacy uAPI being used.
Fixes: 5f03a507b2 ("drm/nouveau: implement 1:1 scheduler - entity relationship")
Reported-by: Timur Tabi <ttabi@nvidia.com>
Tested-by: Timur Tabi <ttabi@nvidia.com>
Closes: https://lore.kernel.org/nouveau/20240131213917.1545604-1-ttabi@nvidia.com/
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240202000606.3526-1-dakr@redhat.com
Issue IP reset before shutdown in order to
complete all upstream requests to the SOC.
Without this DevTLB is complaining about
incomplete transactions and NPU cannot resume from
suspend.
This problem is only happening on recent IFWI
releases.
IP reset in rare corner cases can mess up PCI
configuration, so save it before the reset.
After this happens it is also impossible to
issue PLL requests and D0->D3->D0 cycle is needed
to recover the NPU. Add WP 0 request on power up,
so the PUNIT is always notified about NPU reset.
Use D0/D3 cycle for recovery as it can recover
from failed IP reset and FLR cannot.
Fixes: 3f7c063492 ("accel/ivpu/37xx: Fix hangs related to MMIO reset")
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240207102446.3126981-1-jacek.lawrynowicz@linux.intel.com
Nouveau manages GSP-RM DMA buffers with nvkm_gsp_mem objects. Several of
these buffers are never dealloced. Some of them can be deallocated
right after GSP-RM is initialized, but the rest need to stay until the
driver unloads.
Also futher bullet-proof these objects by poisoning the buffer and
clearing the nvkm_gsp_mem object when it is deallocated. Poisoning
the buffer should trigger an error (or crash) from GSP-RM if it tries
to access the buffer after we've deallocated it, because we were wrong
about when it is safe to deallocate.
Finally, change the mem->size field to a size_t because that's the same
type that dma_alloc_coherent expects.
Cc: <stable@vger.kernel.org> # v6.7
Fixes: 176fdcbddf ("drm/nouveau/gsp/r535: add support for booting GSP-RM")
Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240202230608.1981026-1-ttabi@nvidia.com
This was not supported properly. A buffer was imported to another VPU
context as a separate buffer object with duplicated sgt.
Both exported and imported buffers could be DMA mapped causing a double
mapping on the same device.
Buffers imported from another VPU context will now just increase
reference count, leaving only a single sgt, fixing the problem above.
Buffers still can't be shared among VPU contexts because each has its
own MMU mapping and ivpu_bo only supports single MMU mappings.
The solution would be to use a mapping list as in panfrost or etnaviv
drivers and it will be implemented in future if required.
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Andrzej Kacprowski <andrzej.kacprowski@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240115134434.493839-8-jacek.lawrynowicz@linux.intel.com
