ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faultsgrafted

When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set,
a user fault may trigger show_pte() without any lock.
If another thread in the same process concurrently calls munmap(),
the page table pages may be freed while show_pte() is still traversing
them, causing a use-after-free in show_pte().

If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table
of PMD are freed when show_pte() is running.

Acquire mmap_write_lock() around show_pte() for user faults to fix the
contention.

For user faults, additionally restrict that show_pte() is called only
when the addr is a user-space address (addr < TASK_SIZE). This is because
the lock of tsk->mm only protects the virtual memory of user address space,
furthermore, dumping the page tables of a kernel-space address for user
faults is unnecessary and may have security implications.

Keep everything unchanged for kernel faults, because the kernel is
already in the "oops" state, acquiring a lock may risk a deadlock.

Co-developed-by: Qi Xi <xiqi2@huawei.com>

Fixes: 6d021b724481 ("ARM: dump pgd, pmd and pte states on unhandled data abort faults")
Link: https://lore.kernel.org/20260716014022.2823-1-xieyuanbin1@huawei.com
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

20 files changed, 353 insertions, 0 deletions

diff --git a/Documentation/gpu/xe/index.rst b/Documentation/gpu/xe/index.rst
new file mode 100644
index 000000000..665c0e936
--- /dev/null
+++ b/Documentation/gpu/xe/index.rst
@@ -0,0 +1,37 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+.. _drm/xe:
+
+=======================
+drm/xe Intel GFX Driver
+=======================
+
+The drm/xe driver supports some future GFX cards with rendering, display,
+compute and media. Support for currently available platforms like TGL, ADL,
+DG2, etc is provided to prototype the driver.
+
+The display, or :ref:`drm-kms`, support for drm/xe is provided by
+:ref:`drm/intel-display`, and shared with :ref:`drm/i915 <drm/i915>`.
+
+.. toctree::
+   :titlesonly:
+
+   xe_mm
+   xe_map
+   xe_migrate
+   xe_exec_queue
+   xe_cs
+   xe_pm
+   xe_gt_freq
+   xe_pcode
+   xe_gt_mcr
+   xe_wa
+   xe_rtp
+   xe_firmware
+   xe_tile
+   xe_debugging
+   xe_devcoredump
+   xe_device
+   xe-drm-usage-stats.rst
+   xe_configfs
+   xe_gt_stats
diff --git a/Documentation/gpu/xe/xe-drm-usage-stats.rst b/Documentation/gpu/xe/xe-drm-usage-stats.rst
new file mode 100644
index 000000000..482d503ae
--- /dev/null
+++ b/Documentation/gpu/xe/xe-drm-usage-stats.rst
@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+.. _xe-usage-stats:
+
+========================================
+Xe DRM client usage stats implementation
+========================================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_drm_client.c
+   :doc: DRM Client usage stats
diff --git a/Documentation/gpu/xe/xe_configfs.rst b/Documentation/gpu/xe/xe_configfs.rst
new file mode 100644
index 000000000..7f8ec39dc
--- /dev/null
+++ b/Documentation/gpu/xe/xe_configfs.rst
@@ -0,0 +1,16 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+.. _xe_configfs:
+
+===========
+Xe Configfs
+===========
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_configfs.c
+   :doc: Xe Configfs
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_configfs.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_cs.rst b/Documentation/gpu/xe/xe_cs.rst
new file mode 100644
index 000000000..e379aed4f
--- /dev/null
+++ b/Documentation/gpu/xe/xe_cs.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==================
+Command submission
+==================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_exec.c
+   :doc: Execbuf (User GPU command submission)
diff --git a/Documentation/gpu/xe/xe_debugging.rst b/Documentation/gpu/xe/xe_debugging.rst
new file mode 100644
index 000000000..d65e56ff3
--- /dev/null
+++ b/Documentation/gpu/xe/xe_debugging.rst
@@ -0,0 +1,7 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=========
+Debugging
+=========
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_assert.h
diff --git a/Documentation/gpu/xe/xe_devcoredump.rst b/Documentation/gpu/xe/xe_devcoredump.rst
new file mode 100644
index 000000000..ae4ec0e34
--- /dev/null
+++ b/Documentation/gpu/xe/xe_devcoredump.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==================
+Xe Device Coredump
+==================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_devcoredump.c
+   :doc: Xe device coredump
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_devcoredump.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_device.rst b/Documentation/gpu/xe/xe_device.rst
new file mode 100644
index 000000000..39a937b97
--- /dev/null
+++ b/Documentation/gpu/xe/xe_device.rst
@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+.. _xe-device-wedging:
+
+==================
+Xe Device Wedging
+==================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_device.c
+   :doc: Xe Device Wedging
diff --git a/Documentation/gpu/xe/xe_exec_queue.rst b/Documentation/gpu/xe/xe_exec_queue.rst
new file mode 100644
index 000000000..870780621
--- /dev/null
+++ b/Documentation/gpu/xe/xe_exec_queue.rst
@@ -0,0 +1,34 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+===============
+Execution Queue
+===============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_exec_queue.c
+   :doc: Execution Queue
+
+Multi Queue Group
+=================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_exec_queue.c
+   :doc: Multi Queue Group
+
+.. _multi-queue-group-guc-interface:
+
+Multi Queue Group GuC interface
+===============================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_guc_submit.c
+   :doc: Multi Queue Group GuC interface
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_exec_queue_types.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_exec_queue.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_exec_queue.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_firmware.rst b/Documentation/gpu/xe/xe_firmware.rst
new file mode 100644
index 000000000..d3030d1c9
--- /dev/null
+++ b/Documentation/gpu/xe/xe_firmware.rst
@@ -0,0 +1,46 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+========
+Firmware
+========
+
+Firmware Layout
+===============
+
+.. kernel-doc:: drivers/gpu/drm/xe/abi/uc_fw_abi.h
+   :doc: CSS-based Firmware Layout
+
+.. kernel-doc:: drivers/gpu/drm/xe/abi/uc_fw_abi.h
+   :doc: GSC-based Firmware Layout
+
+Write Once Protected Content Memory (WOPCM) Layout
+==================================================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_wopcm.c
+   :doc: Write Once Protected Content Memory (WOPCM) Layout
+
+GuC CTB Blob
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_guc_ct.c
+   :doc: GuC CTB Blob
+
+GuC Power Conservation (PC)
+===========================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_guc_pc.c
+   :doc: GuC Power Conservation (PC)
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_guc_rc.c
+   :doc: GuC Render C-states (GuC RC)
+
+PCIe Gen5 Limitations
+=====================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_device_sysfs.c
+   :doc: PCIe Gen5 Limitations
+
+Internal API
+============
+
+TODO
diff --git a/Documentation/gpu/xe/xe_gt_freq.rst b/Documentation/gpu/xe/xe_gt_freq.rst
new file mode 100644
index 000000000..182d6aabe
--- /dev/null
+++ b/Documentation/gpu/xe/xe_gt_freq.rst
@@ -0,0 +1,17 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==========================
+Xe GT Frequency Management
+==========================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_gt_freq.c
+   :doc: Xe GT Frequency Management
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_gt_throttle.c
+   :doc: Xe GT Throttle
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_gt_freq.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_gt_mcr.rst b/Documentation/gpu/xe/xe_gt_mcr.rst
new file mode 100644
index 000000000..848c07bc3
--- /dev/null
+++ b/Documentation/gpu/xe/xe_gt_mcr.rst
@@ -0,0 +1,13 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==============================================
+GT Multicast/Replicated (MCR) Register Support
+==============================================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_gt_mcr.c
+   :doc: GT Multicast/Replicated (MCR) Register Support
+
+Internal API
+============
+
+TODO
diff --git a/Documentation/gpu/xe/xe_gt_stats.rst b/Documentation/gpu/xe/xe_gt_stats.rst
new file mode 100644
index 000000000..5ff806aba
--- /dev/null
+++ b/Documentation/gpu/xe/xe_gt_stats.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+================
+Xe GT Statistics
+================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_gt_stats.c
+   :doc: Xe GT Statistics
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_gt_stats_types.h
+   :internal:
diff --git a/Documentation/gpu/xe/xe_map.rst b/Documentation/gpu/xe/xe_map.rst
new file mode 100644
index 000000000..a098cfd2d
--- /dev/null
+++ b/Documentation/gpu/xe/xe_map.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=========
+Map Layer
+=========
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_map.h
+   :doc: Map layer
diff --git a/Documentation/gpu/xe/xe_migrate.rst b/Documentation/gpu/xe/xe_migrate.rst
new file mode 100644
index 000000000..f92faec0a
--- /dev/null
+++ b/Documentation/gpu/xe/xe_migrate.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=============
+Migrate Layer
+=============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_migrate_doc.h
+   :doc: Migrate Layer
diff --git a/Documentation/gpu/xe/xe_mm.rst b/Documentation/gpu/xe/xe_mm.rst
new file mode 100644
index 000000000..95864a450
--- /dev/null
+++ b/Documentation/gpu/xe/xe_mm.rst
@@ -0,0 +1,29 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=================
+Memory Management
+=================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_bo_doc.h
+   :doc: Buffer Objects (BO)
+
+GGTT
+====
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_ggtt.c
+   :doc: Global Graphics Translation Table (GGTT)
+
+GGTT Internal API
+-----------------
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_ggtt_types.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_ggtt.c
+   :internal:
+
+Pagetable building
+==================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_pt.c
+   :doc: Pagetable building
diff --git a/Documentation/gpu/xe/xe_pcode.rst b/Documentation/gpu/xe/xe_pcode.rst
new file mode 100644
index 000000000..2a4360112
--- /dev/null
+++ b/Documentation/gpu/xe/xe_pcode.rst
@@ -0,0 +1,23 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=====
+Pcode
+=====
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_pcode.c
+   :doc: PCODE
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_pcode.c
+   :internal:
+
+.. _xe-survivability-mode:
+
+==================
+Survivability Mode
+==================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_survivability_mode.c
+   :doc: Survivability Mode
diff --git a/Documentation/gpu/xe/xe_pm.rst b/Documentation/gpu/xe/xe_pm.rst
new file mode 100644
index 000000000..6781cdfb2
--- /dev/null
+++ b/Documentation/gpu/xe/xe_pm.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+========================
+Runtime Power Management
+========================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_pm.c
+   :doc: Xe Power Management
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_pm.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_rtp.rst b/Documentation/gpu/xe/xe_rtp.rst
new file mode 100644
index 000000000..7fdf4b6c1
--- /dev/null
+++ b/Documentation/gpu/xe/xe_rtp.rst
@@ -0,0 +1,20 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=========================
+Register Table Processing
+=========================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_rtp.c
+   :doc: Register Table Processing
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_rtp_types.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_rtp.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_rtp.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_tile.rst b/Documentation/gpu/xe/xe_tile.rst
new file mode 100644
index 000000000..c33f68dd9
--- /dev/null
+++ b/Documentation/gpu/xe/xe_tile.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==================
+Multi-tile Devices
+==================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_tile.c
+   :doc: Multi-tile Design
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_tile.c
+   :internal:
diff --git a/Documentation/gpu/xe/xe_wa.rst b/Documentation/gpu/xe/xe_wa.rst
new file mode 100644
index 000000000..f8811cc6a
--- /dev/null
+++ b/Documentation/gpu/xe/xe_wa.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+====================
+Hardware workarounds
+====================
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_wa.c
+   :doc: Hardware workarounds
+
+Internal API
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_wa.c
+   :internal: