From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- .../devicetree/bindings/gnss/brcm,bcm4751.yaml | 70 ++++++++++++++++++++ .../devicetree/bindings/gnss/gnss-common.yaml | 49 ++++++++++++++ .../devicetree/bindings/gnss/mediatek.yaml | 60 +++++++++++++++++ .../devicetree/bindings/gnss/sirfstar.yaml | 77 ++++++++++++++++++++++ .../devicetree/bindings/gnss/u-blox,neo-6m.yaml | 73 ++++++++++++++++++++ 5 files changed, 329 insertions(+) create mode 100644 Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml create mode 100644 Documentation/devicetree/bindings/gnss/gnss-common.yaml create mode 100644 Documentation/devicetree/bindings/gnss/mediatek.yaml create mode 100644 Documentation/devicetree/bindings/gnss/sirfstar.yaml create mode 100644 Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml (limited to 'Documentation/devicetree/bindings/gnss') diff --git a/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml b/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml new file mode 100644 index 000000000..c34b86bb7 --- /dev/null +++ b/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml @@ -0,0 +1,70 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gnss/brcm,bcm4751.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Broadcom BCM4751 family GNSS Receiver + +maintainers: + - Johan Hovold + - Linus Walleij + +description: + Broadcom GPS chips can be used over the UART or I2C bus. The UART + bus requires CTS/RTS support. The number of the capsule is more + elaborate than the compatibles BCM4751 may be printed + BCM4751IFBG for example. + +allOf: + - $ref: gnss-common.yaml# + - $ref: /schemas/serial/serial-peripheral-props.yaml# + +properties: + compatible: + enum: + - brcm,bcm4751 + - brcm,bcm4752 + - brcm,bcm4753 + + reg: + description: + The I2C Address, not required on UART buses. + + vdd-auxin-supply: + description: + Main voltage supply, pin name VDD_AUXIN, typically connected + directly to a battery such as LiIon 3.8V battery or a 2.6V supply. + + vddio-supply: + description: + IO voltage supply, pin name VDDIO, typically 1.8V + + reset-gpios: + maxItems: 1 + description: An optional active low reset line, should be flagged with + GPIO_ACTIVE_LOW. + + enable-gpios: + description: Enable GPIO line, connected to pins named REGPU or NSTANDBY. + If the line is active low such as NSTANDBY, it should be tagged + GPIO_ACTIVE_LOW. + +required: + - compatible + - enable-gpios + +unevaluatedProperties: false + +examples: + - | + #include + serial { + gnss { + compatible = "brcm,bcm4751"; + vdd-auxin-supply = <&vbat>; + reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>; + enable-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>; + current-speed = <38400>; + }; + }; diff --git a/Documentation/devicetree/bindings/gnss/gnss-common.yaml b/Documentation/devicetree/bindings/gnss/gnss-common.yaml new file mode 100644 index 000000000..354c05240 --- /dev/null +++ b/Documentation/devicetree/bindings/gnss/gnss-common.yaml @@ -0,0 +1,49 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gnss/gnss-common.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Common Properties for Global Navigation Satellite Systems (GNSS) + receiver devices + +maintainers: + - Johan Hovold + +description: | + This document defines device tree properties common to Global Navigation + Satellite System receivers. + +properties: + $nodename: + pattern: "^gnss(@.*)?$" + + lna-supply: + description: A separate regulator supplying power for the Low Noise + Amplifier (LNA). This is an amplifier connected between the GNSS + device and the receiver antenna. + + enable-gpios: + description: A GPIO line that will enable the GNSS receiver when + asserted. If this line is active low, the GPIO phandle should + consequently be tagged with the GPIO_ACTIVE_LOW flag so the operating + system can rely on asserting the line to enable the GNSS device. + maxItems: 1 + + timepulse-gpios: + description: Timepulse signal + maxItems: 1 + +additionalProperties: true + +examples: + - | + #include + serial { + gnss { + compatible = "u-blox,neo-8"; + vcc-supply = <&gnss_reg>; + timepulse-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>; + current-speed = <4800>; + }; + }; diff --git a/Documentation/devicetree/bindings/gnss/mediatek.yaml b/Documentation/devicetree/bindings/gnss/mediatek.yaml new file mode 100644 index 000000000..2b9e5be4e --- /dev/null +++ b/Documentation/devicetree/bindings/gnss/mediatek.yaml @@ -0,0 +1,60 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gnss/mediatek.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Mediatek GNSS Receiver + +maintainers: + - Johan Hovold + +description: + Mediatek chipsets are used in GNSS-receiver modules produced by several + vendors and can use a UART interface. + +allOf: + - $ref: gnss-common.yaml# + - $ref: /schemas/serial/serial-peripheral-props.yaml# + +properties: + compatible: + const: globaltop,pa6h + + vcc-supply: + description: + Main voltage regulator, pin name VCC. + + reset-gpios: + maxItems: 1 + description: An optional reset line, with names such as RESET or NRESET. + If the line is active low it should be flagged with GPIO_ACTIVE_LOW. + + timepulse-gpios: + description: Comes with pin names such as PPS1 or 1PPS. + + gnss-fix-gpios: + maxItems: 1 + description: GPIO used to determine device position fix state, pin names + FIX or 3D_FIX. + + vbackup-supply: + description: + Regulator providing backup voltage, pin names such as VBAT or VBACKUP. + +required: + - compatible + - vcc-supply + +unevaluatedProperties: false + +examples: + - | + #include + serial { + gnss { + compatible = "globaltop,pa6h"; + vcc-supply = <&vcc_3v3>; + reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>; + }; + }; diff --git a/Documentation/devicetree/bindings/gnss/sirfstar.yaml b/Documentation/devicetree/bindings/gnss/sirfstar.yaml new file mode 100644 index 000000000..7e5da89a5 --- /dev/null +++ b/Documentation/devicetree/bindings/gnss/sirfstar.yaml @@ -0,0 +1,77 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gnss/sirfstar.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: SiRFstar GNSS Receiver + +maintainers: + - Johan Hovold + +description: + The SiRFstar GNSS receivers have incarnated over the years in different + chips, starting from the SiRFstarIII which was a chip that was introduced in + 2004 and used in a lot of dedicated GPS devices. In 2009 SiRF was acquired + by CSR (Cambridge Silicon Radio) and in 2012 the CSR GPS business was + acquired by Samsung, while some products remained with CSR. In 2014 CSR + was acquired by Qualcomm who still sell some of the SiRF products. + + SiRF chips can be used over UART, I2C or SPI buses. + +allOf: + - $ref: gnss-common.yaml# + - $ref: /schemas/serial/serial-peripheral-props.yaml# + +properties: + compatible: + enum: + - csr,gsd4t + - csr,csrg05ta03-icje-r + - fastrax,uc430 + - linx,r4 + - wi2wi,w2sg0004 + - wi2wi,w2sg0008i + - wi2wi,w2sg0084i + + reg: + description: + The I2C Address, SPI chip select address. Not required on UART buses. + + vcc-supply: + description: + Main voltage regulator, pin names such as 3V3_IN, VCC, VDD. + + reset-gpios: + maxItems: 1 + description: An optional active low reset line, should be flagged with + GPIO_ACTIVE_LOW. + + sirf,onoff-gpios: + maxItems: 1 + description: GPIO used to power on and off device, pin name ON_OFF. + + sirf,wakeup-gpios: + maxItems: 1 + description: GPIO used to determine device power state, pin names such + as RFPWRUP, WAKEUP. + +required: + - compatible + - vcc-supply + +unevaluatedProperties: false + +examples: + - | + #include + serial { + gnss { + compatible = "wi2wi,w2sg0084i"; + vcc-supply = <&gnss_vcc_reg>; + reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>; + sirf,onoff-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>; + sirf,wakeup-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>; + current-speed = <38400>; + }; + }; diff --git a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml new file mode 100644 index 000000000..b349b7bc0 --- /dev/null +++ b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml @@ -0,0 +1,73 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gnss/u-blox,neo-6m.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: u-blox GNSS receiver + +allOf: + - $ref: gnss-common.yaml# + - $ref: /schemas/serial/serial-peripheral-props.yaml# + +maintainers: + - Johan Hovold + +description: > + The u-blox GNSS receivers can use UART, DDC (I2C), SPI and USB interfaces. + +properties: + compatible: + oneOf: + - enum: + - u-blox,neo-6m + - u-blox,neo-8 + - u-blox,neo-m8 + - items: + - const: u-blox,neo-m9 + - const: u-blox,neo-m8 + + reg: + description: > + The DDC Slave Address, SPI chip select address, the number of the USB hub + port or the USB host-controller port to which this device is attached, + depending on the bus used. Required for the DDC, SPI or USB busses. + + reset-gpios: + maxItems: 1 + + safeboot-gpios: + maxItems: 1 + + vcc-supply: + description: > + Main voltage regulator + + u-blox,extint-gpios: + maxItems: 1 + description: > + GPIO connected to the "external interrupt" input pin + + v-bckp-supply: + description: > + Backup voltage regulator + +required: + - compatible + - vcc-supply + +unevaluatedProperties: false + +examples: + - | + #include + + serial { + gnss { + compatible = "u-blox,neo-8"; + v-bckp-supply = <&gnss_v_bckp_reg>; + vcc-supply = <&gnss_vcc_reg>; + reset-gpios = <&gpio 1 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>; + safeboot-gpios = <&gpio 2 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>; + }; + }; -- cgit v1.3.1