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, 119 insertions, 0 deletions

diff --git a/include/dt-bindings/clock/imx7ulp-clock.h b/include/dt-bindings/clock/imx7ulp-clock.h
new file mode 100644
index 000000000..b58370d14
--- /dev/null
+++ b/include/dt-bindings/clock/imx7ulp-clock.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017~2018 NXP
+ *
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_IMX7ULP_H
+#define __DT_BINDINGS_CLOCK_IMX7ULP_H
+
+/* SCG1 */
+
+#define IMX7ULP_CLK_DUMMY		0
+#define IMX7ULP_CLK_ROSC		1
+#define IMX7ULP_CLK_SOSC		2
+#define IMX7ULP_CLK_FIRC		3
+#define IMX7ULP_CLK_SPLL_PRE_SEL	4
+#define IMX7ULP_CLK_SPLL_PRE_DIV	5
+#define IMX7ULP_CLK_SPLL		6
+#define IMX7ULP_CLK_SPLL_POST_DIV1	7
+#define IMX7ULP_CLK_SPLL_POST_DIV2	8
+#define IMX7ULP_CLK_SPLL_PFD0		9
+#define IMX7ULP_CLK_SPLL_PFD1		10
+#define IMX7ULP_CLK_SPLL_PFD2		11
+#define IMX7ULP_CLK_SPLL_PFD3		12
+#define IMX7ULP_CLK_SPLL_PFD_SEL	13
+#define IMX7ULP_CLK_SPLL_SEL		14
+#define IMX7ULP_CLK_APLL_PRE_SEL	15
+#define IMX7ULP_CLK_APLL_PRE_DIV	16
+#define IMX7ULP_CLK_APLL		17
+#define IMX7ULP_CLK_APLL_POST_DIV1	18
+#define IMX7ULP_CLK_APLL_POST_DIV2	19
+#define IMX7ULP_CLK_APLL_PFD0		20
+#define IMX7ULP_CLK_APLL_PFD1		21
+#define IMX7ULP_CLK_APLL_PFD2		22
+#define IMX7ULP_CLK_APLL_PFD3		23
+#define IMX7ULP_CLK_APLL_PFD_SEL	24
+#define IMX7ULP_CLK_APLL_SEL		25
+#define IMX7ULP_CLK_UPLL		26
+#define IMX7ULP_CLK_SYS_SEL		27
+#define IMX7ULP_CLK_CORE_DIV		28
+#define IMX7ULP_CLK_BUS_DIV		29
+#define IMX7ULP_CLK_PLAT_DIV		30
+#define IMX7ULP_CLK_DDR_SEL		31
+#define IMX7ULP_CLK_DDR_DIV		32
+#define IMX7ULP_CLK_NIC_SEL		33
+#define IMX7ULP_CLK_NIC0_DIV		34
+#define IMX7ULP_CLK_GPU_DIV		35
+#define IMX7ULP_CLK_NIC1_DIV		36
+#define IMX7ULP_CLK_NIC1_BUS_DIV	37
+#define IMX7ULP_CLK_NIC1_EXT_DIV	38
+/* IMX7ULP_CLK_MIPI_PLL is unsupported and shouldn't be used in DT */
+#define IMX7ULP_CLK_MIPI_PLL		39
+#define IMX7ULP_CLK_SIRC		40
+#define IMX7ULP_CLK_SOSC_BUS_CLK	41
+#define IMX7ULP_CLK_FIRC_BUS_CLK	42
+#define IMX7ULP_CLK_SPLL_BUS_CLK	43
+#define IMX7ULP_CLK_HSRUN_SYS_SEL	44
+#define IMX7ULP_CLK_HSRUN_CORE_DIV	45
+
+#define IMX7ULP_CLK_CORE		46
+#define IMX7ULP_CLK_HSRUN_CORE		47
+
+#define IMX7ULP_CLK_SCG1_END		48
+
+/* PCC2 */
+#define IMX7ULP_CLK_DMA1		0
+#define IMX7ULP_CLK_RGPIO2P1		1
+#define IMX7ULP_CLK_FLEXBUS		2
+#define IMX7ULP_CLK_SEMA42_1		3
+#define IMX7ULP_CLK_DMA_MUX1		4
+#define IMX7ULP_CLK_CAAM		6
+#define IMX7ULP_CLK_LPTPM4		7
+#define IMX7ULP_CLK_LPTPM5		8
+#define IMX7ULP_CLK_LPIT1		9
+#define IMX7ULP_CLK_LPSPI2		10
+#define IMX7ULP_CLK_LPSPI3		11
+#define IMX7ULP_CLK_LPI2C4		12
+#define IMX7ULP_CLK_LPI2C5		13
+#define IMX7ULP_CLK_LPUART4		14
+#define IMX7ULP_CLK_LPUART5		15
+#define IMX7ULP_CLK_FLEXIO1		16
+#define IMX7ULP_CLK_USB0		17
+#define IMX7ULP_CLK_USB1		18
+#define IMX7ULP_CLK_USB_PHY		19
+#define IMX7ULP_CLK_USB_PL301		20
+#define IMX7ULP_CLK_USDHC0		21
+#define IMX7ULP_CLK_USDHC1		22
+#define IMX7ULP_CLK_WDG1		23
+#define IMX7ULP_CLK_WDG2		24
+
+#define IMX7ULP_CLK_PCC2_END		25
+
+/* PCC3 */
+#define IMX7ULP_CLK_LPTPM6		0
+#define IMX7ULP_CLK_LPTPM7		1
+#define IMX7ULP_CLK_LPI2C6		2
+#define IMX7ULP_CLK_LPI2C7		3
+#define IMX7ULP_CLK_LPUART6		4
+#define IMX7ULP_CLK_LPUART7		5
+#define IMX7ULP_CLK_VIU			6
+#define IMX7ULP_CLK_DSI			7
+#define IMX7ULP_CLK_LCDIF		8
+#define IMX7ULP_CLK_MMDC		9
+#define IMX7ULP_CLK_PCTLC		10
+#define IMX7ULP_CLK_PCTLD		11
+#define IMX7ULP_CLK_PCTLE		12
+#define IMX7ULP_CLK_PCTLF		13
+#define IMX7ULP_CLK_GPU3D		14
+#define IMX7ULP_CLK_GPU2D		15
+
+#define IMX7ULP_CLK_PCC3_END		16
+
+/* SMC1 */
+#define IMX7ULP_CLK_ARM			0
+
+#define IMX7ULP_CLK_SMC1_END		1
+
+#endif /* __DT_BINDINGS_CLOCK_IMX7ULP_H */