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/virt/acrn/hypercall.h | 306 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 306 insertions(+) create mode 100644 drivers/virt/acrn/hypercall.h (limited to 'drivers/virt/acrn/hypercall.h') diff --git a/drivers/virt/acrn/hypercall.h b/drivers/virt/acrn/hypercall.h new file mode 100644 index 000000000..71d300821 --- /dev/null +++ b/drivers/virt/acrn/hypercall.h @@ -0,0 +1,306 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ACRN HSM: hypercalls of ACRN Hypervisor + */ +#ifndef __ACRN_HSM_HYPERCALL_H +#define __ACRN_HSM_HYPERCALL_H +#include + +/* + * Hypercall IDs of the ACRN Hypervisor + */ +#define _HC_ID(x, y) (((x) << 24) | (y)) + +#define HC_ID 0x80UL + +#define HC_ID_GEN_BASE 0x0UL +#define HC_SOS_REMOVE_CPU _HC_ID(HC_ID, HC_ID_GEN_BASE + 0x01) + +#define HC_ID_VM_BASE 0x10UL +#define HC_CREATE_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x00) +#define HC_DESTROY_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x01) +#define HC_START_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x02) +#define HC_PAUSE_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x03) +#define HC_RESET_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x05) +#define HC_SET_VCPU_REGS _HC_ID(HC_ID, HC_ID_VM_BASE + 0x06) + +#define HC_ID_IRQ_BASE 0x20UL +#define HC_INJECT_MSI _HC_ID(HC_ID, HC_ID_IRQ_BASE + 0x03) +#define HC_VM_INTR_MONITOR _HC_ID(HC_ID, HC_ID_IRQ_BASE + 0x04) +#define HC_SET_IRQLINE _HC_ID(HC_ID, HC_ID_IRQ_BASE + 0x05) + +#define HC_ID_IOREQ_BASE 0x30UL +#define HC_SET_IOREQ_BUFFER _HC_ID(HC_ID, HC_ID_IOREQ_BASE + 0x00) +#define HC_NOTIFY_REQUEST_FINISH _HC_ID(HC_ID, HC_ID_IOREQ_BASE + 0x01) + +#define HC_ID_MEM_BASE 0x40UL +#define HC_VM_SET_MEMORY_REGIONS _HC_ID(HC_ID, HC_ID_MEM_BASE + 0x02) + +#define HC_ID_PCI_BASE 0x50UL +#define HC_SET_PTDEV_INTR _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x03) +#define HC_RESET_PTDEV_INTR _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x04) +#define HC_ASSIGN_PCIDEV _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x05) +#define HC_DEASSIGN_PCIDEV _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x06) +#define HC_ASSIGN_MMIODEV _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x07) +#define HC_DEASSIGN_MMIODEV _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x08) +#define HC_CREATE_VDEV _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x09) +#define HC_DESTROY_VDEV _HC_ID(HC_ID, HC_ID_PCI_BASE + 0x0A) + +#define HC_ID_PM_BASE 0x80UL +#define HC_PM_GET_CPU_STATE _HC_ID(HC_ID, HC_ID_PM_BASE + 0x00) + +/** + * hcall_sos_remove_cpu() - Remove a vCPU of Service VM + * @cpu: The vCPU to be removed + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_sos_remove_cpu(u64 cpu) +{ + return acrn_hypercall1(HC_SOS_REMOVE_CPU, cpu); +} + +/** + * hcall_create_vm() - Create a User VM + * @vminfo: Service VM GPA of info of User VM creation + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_create_vm(u64 vminfo) +{ + return acrn_hypercall1(HC_CREATE_VM, vminfo); +} + +/** + * hcall_start_vm() - Start a User VM + * @vmid: User VM ID + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_start_vm(u64 vmid) +{ + return acrn_hypercall1(HC_START_VM, vmid); +} + +/** + * hcall_pause_vm() - Pause a User VM + * @vmid: User VM ID + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_pause_vm(u64 vmid) +{ + return acrn_hypercall1(HC_PAUSE_VM, vmid); +} + +/** + * hcall_destroy_vm() - Destroy a User VM + * @vmid: User VM ID + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_destroy_vm(u64 vmid) +{ + return acrn_hypercall1(HC_DESTROY_VM, vmid); +} + +/** + * hcall_reset_vm() - Reset a User VM + * @vmid: User VM ID + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_reset_vm(u64 vmid) +{ + return acrn_hypercall1(HC_RESET_VM, vmid); +} + +/** + * hcall_set_vcpu_regs() - Set up registers of virtual CPU of a User VM + * @vmid: User VM ID + * @regs_state: Service VM GPA of registers state + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_set_vcpu_regs(u64 vmid, u64 regs_state) +{ + return acrn_hypercall2(HC_SET_VCPU_REGS, vmid, regs_state); +} + +/** + * hcall_inject_msi() - Deliver a MSI interrupt to a User VM + * @vmid: User VM ID + * @msi: Service VM GPA of MSI message + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_inject_msi(u64 vmid, u64 msi) +{ + return acrn_hypercall2(HC_INJECT_MSI, vmid, msi); +} + +/** + * hcall_vm_intr_monitor() - Set a shared page for User VM interrupt statistics + * @vmid: User VM ID + * @addr: Service VM GPA of the shared page + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_vm_intr_monitor(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_VM_INTR_MONITOR, vmid, addr); +} + +/** + * hcall_set_irqline() - Set or clear an interrupt line + * @vmid: User VM ID + * @op: Service VM GPA of interrupt line operations + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_set_irqline(u64 vmid, u64 op) +{ + return acrn_hypercall2(HC_SET_IRQLINE, vmid, op); +} + +/** + * hcall_set_ioreq_buffer() - Set up the shared buffer for I/O Requests. + * @vmid: User VM ID + * @buffer: Service VM GPA of the shared buffer + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_set_ioreq_buffer(u64 vmid, u64 buffer) +{ + return acrn_hypercall2(HC_SET_IOREQ_BUFFER, vmid, buffer); +} + +/** + * hcall_notify_req_finish() - Notify ACRN Hypervisor of I/O request completion. + * @vmid: User VM ID + * @vcpu: The vCPU which initiated the I/O request + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_notify_req_finish(u64 vmid, u64 vcpu) +{ + return acrn_hypercall2(HC_NOTIFY_REQUEST_FINISH, vmid, vcpu); +} + +/** + * hcall_set_memory_regions() - Inform the hypervisor to set up EPT mappings + * @regions_pa: Service VM GPA of &struct vm_memory_region_batch + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_set_memory_regions(u64 regions_pa) +{ + return acrn_hypercall1(HC_VM_SET_MEMORY_REGIONS, regions_pa); +} + +/** + * hcall_create_vdev() - Create a virtual device for a User VM + * @vmid: User VM ID + * @addr: Service VM GPA of the &struct acrn_vdev + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_create_vdev(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_CREATE_VDEV, vmid, addr); +} + +/** + * hcall_destroy_vdev() - Destroy a virtual device of a User VM + * @vmid: User VM ID + * @addr: Service VM GPA of the &struct acrn_vdev + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_destroy_vdev(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_DESTROY_VDEV, vmid, addr); +} + +/** + * hcall_assign_mmiodev() - Assign a MMIO device to a User VM + * @vmid: User VM ID + * @addr: Service VM GPA of the &struct acrn_mmiodev + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_assign_mmiodev(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_ASSIGN_MMIODEV, vmid, addr); +} + +/** + * hcall_deassign_mmiodev() - De-assign a PCI device from a User VM + * @vmid: User VM ID + * @addr: Service VM GPA of the &struct acrn_mmiodev + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_deassign_mmiodev(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_DEASSIGN_MMIODEV, vmid, addr); +} + +/** + * hcall_assign_pcidev() - Assign a PCI device to a User VM + * @vmid: User VM ID + * @addr: Service VM GPA of the &struct acrn_pcidev + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_assign_pcidev(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_ASSIGN_PCIDEV, vmid, addr); +} + +/** + * hcall_deassign_pcidev() - De-assign a PCI device from a User VM + * @vmid: User VM ID + * @addr: Service VM GPA of the &struct acrn_pcidev + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_deassign_pcidev(u64 vmid, u64 addr) +{ + return acrn_hypercall2(HC_DEASSIGN_PCIDEV, vmid, addr); +} + +/** + * hcall_set_ptdev_intr() - Configure an interrupt for an assigned PCI device. + * @vmid: User VM ID + * @irq: Service VM GPA of the &struct acrn_ptdev_irq + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_set_ptdev_intr(u64 vmid, u64 irq) +{ + return acrn_hypercall2(HC_SET_PTDEV_INTR, vmid, irq); +} + +/** + * hcall_reset_ptdev_intr() - Reset an interrupt for an assigned PCI device. + * @vmid: User VM ID + * @irq: Service VM GPA of the &struct acrn_ptdev_irq + * + * Return: 0 on success, <0 on failure + */ +static inline long hcall_reset_ptdev_intr(u64 vmid, u64 irq) +{ + return acrn_hypercall2(HC_RESET_PTDEV_INTR, vmid, irq); +} + +/* + * hcall_get_cpu_state() - Get P-states and C-states info from the hypervisor + * @state: Service VM GPA of buffer of P-states and C-states + */ +static inline long hcall_get_cpu_state(u64 cmd, u64 state) +{ + return acrn_hypercall2(HC_PM_GET_CPU_STATE, cmd, state); +} + +#endif /* __ACRN_HSM_HYPERCALL_H */ -- cgit v1.3.1