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, 107 insertions, 0 deletions

diff --git a/drivers/phy/amlogic/Kconfig b/drivers/phy/amlogic/Kconfig
new file mode 100644
index 000000000..ce7ba3eb2
--- /dev/null
+++ b/drivers/phy/amlogic/Kconfig
@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Amlogic platforms
+#
+config PHY_MESON8_HDMI_TX
+	tristate "Meson8, Meson8b and Meson8m2 HDMI TX PHY driver"
+	depends on (ARCH_MESON && ARM) || COMPILE_TEST
+	depends on OF
+	select MFD_SYSCON
+	help
+	  Enable this to support the HDMI TX PHYs found in Meson8,
+	  Meson8b and Meson8m2 SoCs.
+	  If unsure, say N.
+
+config PHY_MESON8B_USB2
+	tristate "Meson8, Meson8b, Meson8m2 and GXBB USB2 PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	depends on USB_SUPPORT
+	select USB_COMMON
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson8,
+	  Meson8b and GXBB SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_GXL_USB2
+	tristate "Meson GXL and GXM USB2 PHY drivers"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson
+	  GXL and GXM SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_G12A_MIPI_DPHY_ANALOG
+	tristate "Meson G12A MIPI Analog DPHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select MFD_SYSCON
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI Analog DPHY found in Meson G12A
+	  SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_G12A_USB2
+	tristate "Meson G12A USB2 PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson
+	  G12A SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_G12A_USB3_PCIE
+	tristate "Meson G12A USB3+PCIE Combo PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB3 + PCIE Combo PHY found
+	  in Meson G12A SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_AXG_PCIE
+	tristate "Meson AXG PCIE PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson MIPI + PCIE PHY found
+	  in Meson AXG SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_AXG_MIPI_PCIE_ANALOG
+	tristate "Meson AXG MIPI + PCIE analog PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI + PCIE analog PHY
+	  found in Meson AXG SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_AXG_MIPI_DPHY
+	tristate "Meson AXG MIPI DPHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI DPHY found in Meson AXG
+	  SoCs.
+	  If unsure, say N.