x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

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) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 129 insertions, 0 deletions

diff --git a/drivers/mfd/timberdale.h b/drivers/mfd/timberdale.h
new file mode 100644
index 000000000..db7b434f7
--- /dev/null
+++ b/drivers/mfd/timberdale.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * timberdale.h timberdale FPGA MFD driver defines
+ * Copyright (c) 2009 Intel Corporation
+ */
+
+/* Supports:
+ * Timberdale FPGA
+ */
+
+#ifndef MFD_TIMBERDALE_H
+#define MFD_TIMBERDALE_H
+
+#define DRV_VERSION		"0.3"
+
+/* This driver only support versions >= 3.8 and < 4.0  */
+#define TIMB_SUPPORTED_MAJOR	3
+
+/* This driver only support minor >= 8 */
+#define TIMB_REQUIRED_MINOR	8
+
+/* Registers of the control area */
+#define TIMB_REV_MAJOR	0x00
+#define TIMB_REV_MINOR	0x04
+#define TIMB_HW_CONFIG	0x08
+#define TIMB_SW_RST	0x40
+
+/* bits in the TIMB_HW_CONFIG register */
+#define TIMB_HW_CONFIG_SPI_8BIT	0x80
+
+#define TIMB_HW_VER_MASK	0x0f
+#define TIMB_HW_VER0		0x00
+#define TIMB_HW_VER1		0x01
+#define TIMB_HW_VER2		0x02
+#define TIMB_HW_VER3		0x03
+
+#define OCORESOFFSET	0x0
+#define OCORESEND	0x1f
+
+#define SPIOFFSET	0x80
+#define SPIEND		0xff
+
+#define UARTLITEOFFSET	0x100
+#define UARTLITEEND	0x10f
+
+#define RDSOFFSET	0x180
+#define RDSEND		0x183
+
+#define ETHOFFSET	0x300
+#define ETHEND		0x3ff
+
+#define GPIOOFFSET	0x400
+#define GPIOEND		0x7ff
+
+#define CHIPCTLOFFSET	0x800
+#define CHIPCTLEND	0x8ff
+#define CHIPCTLSIZE	(CHIPCTLEND - CHIPCTLOFFSET + 1)
+
+#define INTCOFFSET	0xc00
+#define INTCEND		0xfff
+#define INTCSIZE	(INTCEND - INTCOFFSET)
+
+#define MOSTOFFSET	0x1000
+#define MOSTEND		0x13ff
+
+#define UARTOFFSET	0x1400
+#define UARTEND		0x17ff
+
+#define XIICOFFSET	0x1800
+#define XIICEND		0x19ff
+
+#define I2SOFFSET	0x1C00
+#define I2SEND		0x1fff
+
+#define LOGIWOFFSET	0x30000
+#define LOGIWEND	0x37fff
+
+#define MLCOREOFFSET	0x40000
+#define MLCOREEND	0x43fff
+
+#define DMAOFFSET	0x01000000
+#define DMAEND		0x013fffff
+
+/* SDHC0 is placed in PCI bar 1 */
+#define SDHC0OFFSET	0x00
+#define SDHC0END	0xff
+
+/* SDHC1 is placed in PCI bar 2 */
+#define SDHC1OFFSET	0x00
+#define SDHC1END	0xff
+
+#define PCI_VENDOR_ID_TIMB	0x10ee
+#define PCI_DEVICE_ID_TIMB	0xa123
+
+#define IRQ_TIMBERDALE_INIC		0
+#define IRQ_TIMBERDALE_MLB		1
+#define IRQ_TIMBERDALE_GPIO		2
+#define IRQ_TIMBERDALE_I2C		3
+#define IRQ_TIMBERDALE_UART		4
+#define IRQ_TIMBERDALE_DMA		5
+#define IRQ_TIMBERDALE_I2S		6
+#define IRQ_TIMBERDALE_TSC_INT		7
+#define IRQ_TIMBERDALE_SDHC		8
+#define IRQ_TIMBERDALE_ADV7180		9
+#define IRQ_TIMBERDALE_ETHSW_IF		10
+#define IRQ_TIMBERDALE_SPI		11
+#define IRQ_TIMBERDALE_UARTLITE		12
+#define IRQ_TIMBERDALE_MLCORE		13
+#define IRQ_TIMBERDALE_MLCORE_BUF	14
+#define IRQ_TIMBERDALE_RDS		15
+#define TIMBERDALE_NR_IRQS		16
+
+#define GPIO_PIN_ASCB		8
+#define GPIO_PIN_INIC_RST	14
+#define GPIO_PIN_BT_RST		15
+
+/* DMA Channels */
+#define DMA_UART_RX         0
+#define DMA_UART_TX         1
+#define DMA_MLB_RX          2
+#define DMA_MLB_TX          3
+#define DMA_VIDEO_RX        4
+#define DMA_VIDEO_DROP      5
+#define DMA_SDHCI_RX        6
+#define DMA_SDHCI_TX        7
+#define DMA_ETH_RX          8
+#define DMA_ETH_TX          9
+
+#endif