From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions 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) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/pci/hotplug/Kconfig | 186 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 drivers/pci/hotplug/Kconfig (limited to 'drivers/pci/hotplug/Kconfig') diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig new file mode 100644 index 000000000..3207860b5 --- /dev/null +++ b/drivers/pci/hotplug/Kconfig @@ -0,0 +1,186 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# PCI Hotplug support +# + +menuconfig HOTPLUG_PCI + bool "Support for PCI Hotplug" + depends on PCI && SYSFS + default y if USB4 + help + Say Y here if you have a motherboard with a PCI Hotplug controller. + This allows you to add and remove PCI cards while the machine is + powered up and running. + + Thunderbolt/USB4 PCIe tunneling depends on native PCIe hotplug. + + When in doubt, say N. + +if HOTPLUG_PCI + +config HOTPLUG_PCI_COMPAQ + tristate "Compaq PCI Hotplug driver" + depends on X86 && PCI_BIOS + help + Say Y here if you have a motherboard with a Compaq PCI Hotplug + controller. + + To compile this driver as a module, choose M here: the + module will be called cpqphp. + + When in doubt, say N. + +config HOTPLUG_PCI_COMPAQ_NVRAM + bool "Save configuration into NVRAM on Compaq servers" + depends on HOTPLUG_PCI_COMPAQ + help + Say Y here if you have a Compaq server that has a PCI Hotplug + controller. This will allow the PCI Hotplug driver to store the PCI + system configuration options in NVRAM. + + When in doubt, say N. + +config HOTPLUG_PCI_IBM + tristate "IBM PCI Hotplug driver" + depends on X86_IO_APIC && X86 && PCI_BIOS + help + Say Y here if you have a motherboard with a IBM PCI Hotplug + controller. + + To compile this driver as a module, choose M here: the + module will be called ibmphp. + + When in doubt, say N. + +config HOTPLUG_PCI_ACPI + bool "ACPI PCI Hotplug driver" + depends on HOTPLUG_PCI=y && ((!ACPI_DOCK && ACPI) || (ACPI_DOCK)) + help + Say Y here if you have a system that supports PCI Hotplug using + ACPI. + + When in doubt, say N. + +config HOTPLUG_PCI_ACPI_AMPERE_ALTRA + tristate "ACPI PCI Hotplug driver Ampere Altra extensions" + depends on HOTPLUG_PCI_ACPI + depends on HAVE_ARM_SMCCC_DISCOVERY + help + Say Y here if you have an Ampere Altra system. + + To compile this driver as a module, choose M here: the + module will be called acpiphp_ampere_altra. + + When in doubt, say N. + +config HOTPLUG_PCI_ACPI_IBM + tristate "ACPI PCI Hotplug driver IBM extensions" + depends on HOTPLUG_PCI_ACPI + help + Say Y here if you have an IBM system that supports PCI Hotplug using + ACPI. + + To compile this driver as a module, choose M here: the + module will be called acpiphp_ibm. + + When in doubt, say N. + +config HOTPLUG_PCI_CPCI + bool "CompactPCI Hotplug driver" + help + Say Y here if you have a CompactPCI system card with CompactPCI + hotswap support per the PICMG 2.1 specification. + + When in doubt, say N. + +config HOTPLUG_PCI_CPCI_ZT5550 + tristate "Ziatech ZT5550 CompactPCI Hotplug driver" + depends on HOTPLUG_PCI_CPCI && X86 + help + Say Y here if you have a Performance Technologies (formerly Intel, + formerly just Ziatech) Ziatech ZT5550 CompactPCI system card. + + To compile this driver as a module, choose M here: the + module will be called cpcihp_zt5550. + + When in doubt, say N. + +config HOTPLUG_PCI_CPCI_GENERIC + tristate "Generic port I/O CompactPCI Hotplug driver" + depends on HOTPLUG_PCI_CPCI && X86 + help + Say Y here if you have a CompactPCI system card that exposes the #ENUM + hotswap signal as a bit in a system register that can be read through + standard port I/O. + + To compile this driver as a module, choose M here: the + module will be called cpcihp_generic. + + When in doubt, say N. + +config HOTPLUG_PCI_OCTEONEP + bool "Marvell OCTEON PCI Hotplug driver" + depends on HOTPLUG_PCI + help + Say Y here if you have an OCTEON PCIe device with a hotplug + controller. This driver enables the non-controller functions of the + device to be registered as hotplug slots. + + When in doubt, say N. + +config HOTPLUG_PCI_SHPC + bool "SHPC PCI Hotplug driver" + help + Say Y here if you have a motherboard with a SHPC PCI Hotplug + controller. + + When in doubt, say N. + +config HOTPLUG_PCI_POWERNV + tristate "PowerPC PowerNV PCI Hotplug driver" + depends on PPC_POWERNV && EEH + select OF_DYNAMIC + help + Say Y here if you run PowerPC PowerNV platform that supports + PCI Hotplug + + To compile this driver as a module, choose M here: the + module will be called pnv-php. + + When in doubt, say N. + +config HOTPLUG_PCI_RPA + tristate "RPA PCI Hotplug driver" + depends on PPC_PSERIES && EEH + help + Say Y here if you have a RPA system that supports PCI Hotplug. + + To compile this driver as a module, choose M here: the + module will be called rpaphp. + + When in doubt, say N. + +config HOTPLUG_PCI_RPA_DLPAR + tristate "RPA Dynamic Logical Partitioning for I/O slots" + depends on HOTPLUG_PCI_RPA + help + Say Y here if your system supports Dynamic Logical Partitioning + for I/O slots. + + To compile this driver as a module, choose M here: the + module will be called rpadlpar_io. + + When in doubt, say N. + +config HOTPLUG_PCI_S390 + bool "System z PCI Hotplug Support" + depends on S390 && 64BIT + help + Say Y here if you want to use the System z PCI Hotplug + driver for PCI devices. Without this driver it is not + possible to access stand-by PCI functions nor to deconfigure + PCI functions. + + When in doubt, say Y. + +endif # HOTPLUG_PCI -- cgit v1.3.1