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, 75 insertions, 0 deletions

diff --git a/drivers/pinctrl/stm32/Kconfig b/drivers/pinctrl/stm32/Kconfig
new file mode 100644
index 000000000..d6a171523
--- /dev/null
+++ b/drivers/pinctrl/stm32/Kconfig
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0-only
+if ARCH_STM32 || COMPILE_TEST
+
+config PINCTRL_STM32
+	tristate
+	depends on OF
+	select PINMUX
+	select GENERIC_PINCONF
+	select GPIOLIB
+	select IRQ_DOMAIN_HIERARCHY
+	select MFD_SYSCON
+
+config PINCTRL_STM32F429
+	bool "STMicroelectronics STM32F429 pin control" if COMPILE_TEST && !MACH_STM32F429
+	depends on OF && HAS_IOMEM
+	default MACH_STM32F429
+	select PINCTRL_STM32
+
+config PINCTRL_STM32F469
+	bool "STMicroelectronics STM32F469 pin control" if COMPILE_TEST && !MACH_STM32F469
+	depends on OF && HAS_IOMEM
+	default MACH_STM32F469
+	select PINCTRL_STM32
+
+config PINCTRL_STM32F746
+	bool "STMicroelectronics STM32F746 pin control" if COMPILE_TEST && !MACH_STM32F746
+	depends on OF && HAS_IOMEM
+	default MACH_STM32F746
+	select PINCTRL_STM32
+
+config PINCTRL_STM32F769
+	bool "STMicroelectronics STM32F769 pin control" if COMPILE_TEST && !MACH_STM32F769
+	depends on OF && HAS_IOMEM
+	default MACH_STM32F769
+	select PINCTRL_STM32
+
+config PINCTRL_STM32H743
+	bool "STMicroelectronics STM32H743 pin control" if COMPILE_TEST && !MACH_STM32H743
+	depends on OF && HAS_IOMEM
+	default MACH_STM32H743
+	select PINCTRL_STM32
+
+config PINCTRL_STM32MP135
+	bool "STMicroelectronics STM32MP135 pin control" if COMPILE_TEST && !MACH_STM32MP13
+	depends on OF && HAS_IOMEM
+	default MACH_STM32MP13
+	select PINCTRL_STM32
+
+config PINCTRL_STM32MP157
+	bool "STMicroelectronics STM32MP157 pin control" if COMPILE_TEST && !MACH_STM32MP157
+	depends on OF && HAS_IOMEM
+	default MACH_STM32MP157
+	select PINCTRL_STM32
+
+config PINCTRL_STM32MP257
+	tristate "STMicroelectronics STM32MP257 pin control"
+	depends on OF && HAS_IOMEM
+	default MACH_STM32MP25 || (ARCH_STM32 && ARM64)
+	select PINCTRL_STM32
+
+config PINCTRL_STM32_HDP
+	tristate "STMicroelectronics STM32 Hardware Debug Port (HDP) pin control"
+	depends on OF && HAS_IOMEM
+	default ARCH_STM32 && !ARM_SINGLE_ARMV7M
+	select PINMUX
+	select GENERIC_PINCONF
+	select GPIOLIB
+	select GPIO_GENERIC
+	help
+	  The Hardware Debug Port allows the observation of internal signals.
+	  It uses configurable multiplexer to route signals in a dedicated observation register.
+	  This driver also permits the observation of signals on external SoC pins.
+	  It permits the observation of up to 16 signals per HDP line.
+
+endif