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, 42 insertions, 0 deletions

diff --git a/drivers/pmdomain/bcm/Kconfig b/drivers/pmdomain/bcm/Kconfig
new file mode 100644
index 000000000..b28c9f6d2
--- /dev/null
+++ b/drivers/pmdomain/bcm/Kconfig
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Broadcom PM Domains"
+
+config BCM2835_POWER
+	bool "BCM2835 power domain driver"
+	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
+	default y if ARCH_BCM2835
+	select PM_GENERIC_DOMAINS if PM
+	select RESET_CONTROLLER
+	help
+	  This enables support for the BCM2835 power domains and reset
+	  controller.  Any usage of power domains by the Raspberry Pi
+	  firmware means that Linux usage of the same power domain
+	  must be accessed using the RASPBERRYPI_POWER driver
+
+config RASPBERRYPI_POWER
+	bool "Raspberry Pi power domain driver"
+	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
+	depends on RASPBERRYPI_FIRMWARE=y
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the RPi power domains which can be enabled
+	  or disabled via the RPi firmware.
+
+config BCM_PMB
+	bool "Broadcom PMB (Power Management Bus) driver"
+	depends on ARCH_BCMBCA || (COMPILE_TEST && OF)
+	default ARCH_BCMBCA
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the Broadcom's PMB (Power Management Bus) that
+	  is used for disabling and enabling SoC devices.
+
+config BCM63XX_POWER
+	bool "BCM63xx power domain driver"
+	depends on BMIPS_GENERIC || (COMPILE_TEST && OF)
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the BCM63xx power domains controller on
+	  BCM6318, BCM6328, BCM6362 and BCM63268 SoCs.
+
+endmenu