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, 37 insertions, 0 deletions

diff --git a/drivers/thermal/mediatek/Kconfig b/drivers/thermal/mediatek/Kconfig
new file mode 100644
index 000000000..d82c86d9b
--- /dev/null
+++ b/drivers/thermal/mediatek/Kconfig
@@ -0,0 +1,37 @@
+config MTK_THERMAL
+	tristate "MediaTek thermal drivers"
+	depends on THERMAL_OF
+	help
+	  This is the option for MediaTek thermal software solutions.
+	  Please enable corresponding options to get temperature
+	  information from thermal sensors or turn on throttle
+	  mechaisms for thermal mitigation.
+
+if MTK_THERMAL
+
+config MTK_SOC_THERMAL
+	tristate "AUXADC temperature sensor driver for MediaTek SoCs"
+	depends on HAS_IOMEM
+	help
+	  Enable this option if you want to get SoC temperature
+	  information for MediaTek platforms.
+	  This driver configures thermal controllers to collect
+	  temperature via AUXADC interface.
+
+config MTK_LVTS_THERMAL
+        tristate "LVTS Thermal Driver for MediaTek SoCs"
+        depends on HAS_IOMEM
+        help
+          Enable this option if you want to get SoC temperature
+          information for supported MediaTek platforms.
+          This driver configures LVTS (Low Voltage Thermal Sensor)
+          thermal controllers to collect temperatures via ASIF
+          (Analog Serial Interface).
+
+config MTK_LVTS_THERMAL_DEBUGFS
+       bool "LVTS thermal debugfs"
+       depends on MTK_LVTS_THERMAL && DEBUG_FS
+       help
+         Enable this option to debug the internals of the device driver.
+
+endif