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, 56 insertions, 0 deletions

diff --git a/drivers/pinctrl/airoha/Kconfig b/drivers/pinctrl/airoha/Kconfig
new file mode 100644
index 000000000..22b8f850c
--- /dev/null
+++ b/drivers/pinctrl/airoha/Kconfig
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Airoha pinctrl drivers"
+	depends on ARCH_AIROHA || COMPILE_TEST
+
+config PINCTRL_AIROHA
+	tristate "Airoha pin control"
+	depends on OF
+	depends on ARCH_AIROHA || COMPILE_TEST
+	select PINMUX
+	select GENERIC_PINCONF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GPIOLIB
+	select GPIOLIB_IRQCHIP
+	select REGMAP_MMIO
+	imply PINCTRL_AIROHA_AN7563
+	imply PINCTRL_AIROHA_AN7581
+	imply PINCTRL_AIROHA_AN7583
+	imply PINCTRL_AIROHA_EN7523
+	help
+	  Shared pin controller and gpio driver code for different
+	  Airoha SoCs.
+
+config PINCTRL_AIROHA_AN7563
+	tristate "AN7563 pinctrl"
+	depends on ARM64 || COMPILE_TEST
+	depends on PINCTRL_AIROHA
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on Airoha AN7563 and other compatible SoCs.
+
+config PINCTRL_AIROHA_AN7581
+	tristate "AN7581 pinctrl"
+	depends on ARM64 || COMPILE_TEST
+	depends on PINCTRL_AIROHA
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on Airoha AN7581, AN7566, AN7551 and other compatible SoCs.
+
+config PINCTRL_AIROHA_AN7583
+	tristate "AN7583 pinctrl"
+	depends on ARM64 || COMPILE_TEST
+	depends on PINCTRL_AIROHA
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on Airoha AN7583, AN7553, AN7567 and other compatible SoCs.
+
+config PINCTRL_AIROHA_EN7523
+	tristate "EN7523 pinctrl"
+	depends on ARM || COMPILE_TEST
+	depends on PINCTRL_AIROHA
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on Airoha EN7523, EN7529, EN7562 and other compatible SoCs.
+
+endmenu