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, 57 insertions, 0 deletions

diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
new file mode 100644
index 000000000..a80cf4047
--- /dev/null
+++ b/drivers/spmi/Kconfig
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# SPMI driver configuration
+#
+menuconfig SPMI
+	tristate "SPMI support"
+	help
+	  SPMI (System Power Management Interface) is a two-wire
+	  serial interface between baseband and application processors
+	  and Power Management Integrated Circuits (PMIC).
+
+if SPMI
+
+config SPMI_APPLE
+	tristate "Apple SoC SPMI Controller platform driver"
+	depends on ARCH_APPLE || COMPILE_TEST
+	help
+	  If you say yes to this option, support will be included for the
+	  SPMI controller present on many Apple SoCs, including the
+	  t8103 (M1) and t600x (M1 Pro/Max).
+
+config SPMI_HISI3670
+	tristate "Hisilicon 3670 SPMI Controller"
+	select IRQ_DOMAIN_HIERARCHY
+	depends on ARM64 || COMPILE_TEST
+	depends on HAS_IOMEM
+	help
+	  If you say yes to this option, support will be included for the
+	  built-in SPMI PMIC Arbiter interface on Hisilicon 3670
+	  processors.
+
+config SPMI_MSM_PMIC_ARB
+	tristate "Qualcomm MSM SPMI Controller (PMIC Arbiter)"
+	select IRQ_DOMAIN_HIERARCHY
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on HAS_IOMEM
+	default ARCH_QCOM
+	help
+	  If you say yes to this option, support will be included for the
+	  built-in SPMI PMIC Arbiter interface on Qualcomm MSM family
+	  processors.
+
+	  This is required for communicating with Qualcomm PMICs and
+	  other devices that have the SPMI interface.
+
+config SPMI_MTK_PMIF
+	tristate "Mediatek SPMI Controller (PMIC Arbiter)"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  If you say yes to this option, support will be included for the
+	  built-in SPMI PMIC Arbiter interface on Mediatek family
+	  processors.
+
+	  This is required for communicating with Mediatek PMICs and
+	  other devices that have the SPMI interface.
+
+endif