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, 274 insertions, 0 deletions

diff --git a/Documentation/gpu/intel-display/async-flip.rst b/Documentation/gpu/intel-display/async-flip.rst
new file mode 100644
index 000000000..40f93e885
--- /dev/null
+++ b/Documentation/gpu/intel-display/async-flip.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Asynchronous Page Flip
+======================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_display.c
+   :doc: asynchronous flip implementation
diff --git a/Documentation/gpu/intel-display/atomic.rst b/Documentation/gpu/intel-display/atomic.rst
new file mode 100644
index 000000000..43a473181
--- /dev/null
+++ b/Documentation/gpu/intel-display/atomic.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Atomic Modeset Support
+======================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_atomic.c
+   :doc: atomic modeset support
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_atomic.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/audio.rst b/Documentation/gpu/intel-display/audio.rst
new file mode 100644
index 000000000..eef95df75
--- /dev/null
+++ b/Documentation/gpu/intel-display/audio.rst
@@ -0,0 +1,23 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+High Definition Audio
+=====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_audio.c
+   :doc: High Definition Audio over HDMI and Display Port
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_audio.c
+   :internal:
+
+.. kernel-doc:: include/drm/intel/i915_component.h
+   :internal:
+
+Intel HDMI LPE Audio Support
+============================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_lpe_audio.c
+   :doc: LPE Audio integration for HDMI or DP playback
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_lpe_audio.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/casf.rst b/Documentation/gpu/intel-display/casf.rst
new file mode 100644
index 000000000..406778ccd
--- /dev/null
+++ b/Documentation/gpu/intel-display/casf.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Content Adaptive Sharpness Filter (CASF)
+========================================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_casf.c
+   :doc: Content Adaptive Sharpness Filter (CASF)
diff --git a/Documentation/gpu/intel-display/cdclk.rst b/Documentation/gpu/intel-display/cdclk.rst
new file mode 100644
index 000000000..a66d623b0
--- /dev/null
+++ b/Documentation/gpu/intel-display/cdclk.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Display clocks
+==============
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_cdclk.c
+   :doc: CDCLK / RAWCLK
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_cdclk.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/cmtg.rst b/Documentation/gpu/intel-display/cmtg.rst
new file mode 100644
index 000000000..04edd0bd1
--- /dev/null
+++ b/Documentation/gpu/intel-display/cmtg.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Common Primary Timing Generator (CMTG)
+======================================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_cmtg.c
+   :doc: Common Primary Timing Generator (CMTG)
diff --git a/Documentation/gpu/intel-display/dmc.rst b/Documentation/gpu/intel-display/dmc.rst
new file mode 100644
index 000000000..4368da4c7
--- /dev/null
+++ b/Documentation/gpu/intel-display/dmc.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+.. _drm/intel-display/dmc:
+
+DMC Firmware Support
+====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dmc.c
+   :doc: DMC Firmware Support
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dmc.c
+   :internal:
+
+
+DMC Flip Queue
+==============
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_flipq.c
+   :doc: DMC Flip Queue
+
+DMC wakelock support
+====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dmc_wl.c
+   :doc: DMC wakelock support
diff --git a/Documentation/gpu/intel-display/dpio.rst b/Documentation/gpu/intel-display/dpio.rst
new file mode 100644
index 000000000..84d92ac16
--- /dev/null
+++ b/Documentation/gpu/intel-display/dpio.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+DPIO
+====
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dpio_phy.c
+   :doc: DPIO
diff --git a/Documentation/gpu/intel-display/dpll.rst b/Documentation/gpu/intel-display/dpll.rst
new file mode 100644
index 000000000..c750352e0
--- /dev/null
+++ b/Documentation/gpu/intel-display/dpll.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Display PLLs
+============
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+   :doc: Display PLLs
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dpll_mgr.h
+   :internal:
diff --git a/Documentation/gpu/intel-display/drrs.rst b/Documentation/gpu/intel-display/drrs.rst
new file mode 100644
index 000000000..a5aaba63d
--- /dev/null
+++ b/Documentation/gpu/intel-display/drrs.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Display Refresh Rate Switching (DRRS)
+=====================================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_drrs.c
+   :doc: Display Refresh Rate Switching (DRRS)
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_drrs.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/dsb.rst b/Documentation/gpu/intel-display/dsb.rst
new file mode 100644
index 000000000..857aca599
--- /dev/null
+++ b/Documentation/gpu/intel-display/dsb.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Display State Buffer
+====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dsb.c
+   :doc: DSB
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dsb.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/fbc.rst b/Documentation/gpu/intel-display/fbc.rst
new file mode 100644
index 000000000..de9e19021
--- /dev/null
+++ b/Documentation/gpu/intel-display/fbc.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Frame Buffer Compression (FBC)
+==============================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_fbc.c
+   :doc: Frame Buffer Compression (FBC)
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_fbc.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/fifo-underrun.rst b/Documentation/gpu/intel-display/fifo-underrun.rst
new file mode 100644
index 000000000..5d8f01921
--- /dev/null
+++ b/Documentation/gpu/intel-display/fifo-underrun.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Display FIFO Underrun Reporting
+===============================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_fifo_underrun.c
+   :doc: fifo underrun handling
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_fifo_underrun.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/frontbuffer.rst b/Documentation/gpu/intel-display/frontbuffer.rst
new file mode 100644
index 000000000..7ae38e082
--- /dev/null
+++ b/Documentation/gpu/intel-display/frontbuffer.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Frontbuffer Tracking
+====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_frontbuffer.c
+   :doc: frontbuffer tracking
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_frontbuffer.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_frontbuffer.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/hotplug.rst b/Documentation/gpu/intel-display/hotplug.rst
new file mode 100644
index 000000000..f33bc0087
--- /dev/null
+++ b/Documentation/gpu/intel-display/hotplug.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Hotplug
+=======
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_hotplug.c
+   :doc: Hotplug
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_hotplug.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/index.rst b/Documentation/gpu/intel-display/index.rst
new file mode 100644
index 000000000..01c3d1e57
--- /dev/null
+++ b/Documentation/gpu/intel-display/index.rst
@@ -0,0 +1,44 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+.. _drm/intel-display:
+
+====================
+Intel Display Driver
+====================
+
+The Intel display driver provides the display, or :ref:`drm-kms`, support for
+both the :ref:`drm/xe <drm/xe>` and :ref:`drm/i915 <drm/i915>` Intel GPU
+drivers.
+
+The source code currently resides under ``drivers/gpu/drm/i915/display`` due to
+historical reasons, and it's compiled separately into both drm/xe and drm/i915
+kernel modules.
+
+The drm/xe and drm/i915 drivers are the "core" or "parent" drivers for display,
+as they initialize and own the drm device, and pass that on to the display
+driver. The display driver isn't an independent driver in that sense.
+
+.. toctree::
+   :maxdepth: 1
+   :caption: Detailed display topics
+
+   async-flip
+   atomic
+   audio
+   casf
+   cdclk
+   cmtg
+   dmc
+   dpio
+   dpll
+   drrs
+   dsb
+   fbc
+   fifo-underrun
+   frontbuffer
+   hotplug
+   plane
+   psr
+   snps-phy
+   vbt
diff --git a/Documentation/gpu/intel-display/plane.rst b/Documentation/gpu/intel-display/plane.rst
new file mode 100644
index 000000000..59932a820
--- /dev/null
+++ b/Documentation/gpu/intel-display/plane.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Atomic Plane Helpers
+====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_plane.c
+   :doc: atomic plane helpers
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_plane.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/psr.rst b/Documentation/gpu/intel-display/psr.rst
new file mode 100644
index 000000000..63e56abcd
--- /dev/null
+++ b/Documentation/gpu/intel-display/psr.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Panel Self Refresh PSR (PSR/SRD)
+================================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_psr.c
+   :doc: Panel Self Refresh (PSR/SRD)
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_psr.c
+   :internal:
diff --git a/Documentation/gpu/intel-display/snps-phy.rst b/Documentation/gpu/intel-display/snps-phy.rst
new file mode 100644
index 000000000..c9e333fa7
--- /dev/null
+++ b/Documentation/gpu/intel-display/snps-phy.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Synopsis PHY support
+====================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_snps_phy.c
+   :doc: Synopsis PHY support
diff --git a/Documentation/gpu/intel-display/vbt.rst b/Documentation/gpu/intel-display/vbt.rst
new file mode 100644
index 000000000..be69f7fd7
--- /dev/null
+++ b/Documentation/gpu/intel-display/vbt.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: MIT
+.. Copyright © 2026 Intel Corporation
+
+Video BIOS Table (VBT)
+======================
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_bios.c
+   :doc: Video BIOS Table (VBT)
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_bios.c
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_vbt_defs.h
+   :internal: