From 1039bffd6ae9c75b42b7d148d6c1106134107b66 Mon Sep 17 00:00:00 2001 From: Xie Yuanbin Date: Tue, 28 Jul 2026 03:16:42 +0100 Subject: ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults 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 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) Reviewed-by: Linus Walleij Signed-off-by: Qi Xi Signed-off-by: Xie Yuanbin Signed-off-by: Russell King --- .../trigger-source/adi,util-sigma-delta-spi.yaml | 49 ++++++++++++++++++++++ .../bindings/trigger-source/gpio-trigger.yaml | 40 ++++++++++++++++++ .../bindings/trigger-source/pwm-trigger.yaml | 37 ++++++++++++++++ 3 files changed, 126 insertions(+) create mode 100644 Documentation/devicetree/bindings/trigger-source/adi,util-sigma-delta-spi.yaml create mode 100644 Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml create mode 100644 Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml (limited to 'Documentation/devicetree/bindings/trigger-source') diff --git a/Documentation/devicetree/bindings/trigger-source/adi,util-sigma-delta-spi.yaml b/Documentation/devicetree/bindings/trigger-source/adi,util-sigma-delta-spi.yaml new file mode 100644 index 000000000..ea4661795 --- /dev/null +++ b/Documentation/devicetree/bindings/trigger-source/adi,util-sigma-delta-spi.yaml @@ -0,0 +1,49 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +# Copyright (c) 2025 Analog Devices, Inc. +# Copyright (c) 2025 BayLibre, SAS + +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/trigger-source/adi,util-sigma-delta-spi.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Analog Devices Util Sigma-Delta SPI IP Core + +maintainers: + - David Lechner + +description: + The Util Sigma-Delta SPI is an FPGA IP core from Analog Devices that provides + a SPI offload trigger from the RDY signal of the combined DOUT/RDY pin of + the sigma-delta family of ADCs. + https://analogdevicesinc.github.io/hdl/library/util_sigma_delta_spi/index.html + +properties: + compatible: + const: adi,util-sigma-delta-spi + + reg: + maxItems: 1 + + clocks: + maxItems: 1 + + '#trigger-source-cells': + const: 0 + +required: + - compatible + - reg + - clocks + - '#trigger-source-cells' + +additionalProperties: false + +examples: + - | + trigger@40000 { + reg = <0x40000 0x1000>; + compatible = "adi,util-sigma-delta-spi"; + clocks = <&clk 0>; + #trigger-source-cells = <0>; + }; diff --git a/Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml b/Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml new file mode 100644 index 000000000..1331d153e --- /dev/null +++ b/Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml @@ -0,0 +1,40 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/trigger-source/gpio-trigger.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Generic trigger source using GPIO + +description: A GPIO used as a trigger source. + +maintainers: + - Jonathan Santos + +properties: + compatible: + const: gpio-trigger + + '#trigger-source-cells': + const: 0 + + gpios: + maxItems: 1 + description: GPIO to be used as a trigger source. + +required: + - compatible + - '#trigger-source-cells' + - gpios + +additionalProperties: false + +examples: + - | + #include + + trigger { + compatible = "gpio-trigger"; + #trigger-source-cells = <0>; + gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>; + }; diff --git a/Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml b/Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml new file mode 100644 index 000000000..1eac20031 --- /dev/null +++ b/Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml @@ -0,0 +1,37 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/trigger-source/pwm-trigger.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Generic trigger source using PWM + +description: Remaps a PWM channel as a trigger source. + +maintainers: + - David Lechner + +properties: + compatible: + const: pwm-trigger + + '#trigger-source-cells': + const: 0 + + pwms: + maxItems: 1 + +required: + - compatible + - '#trigger-source-cells' + - pwms + +additionalProperties: false + +examples: + - | + trigger { + compatible = "pwm-trigger"; + #trigger-source-cells = <0>; + pwms = <&pwm 0 1000000 0>; + }; -- cgit v1.3.1