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/rpmsg/Kconfig | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 drivers/rpmsg/Kconfig (limited to 'drivers/rpmsg/Kconfig') diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig new file mode 100644 index 000000000..d3795860f --- /dev/null +++ b/drivers/rpmsg/Kconfig @@ -0,0 +1,84 @@ +# SPDX-License-Identifier: GPL-2.0 + +menu "Rpmsg drivers" + +# RPMSG always gets selected by whoever wants it +config RPMSG + tristate + +config RPMSG_CHAR + tristate "RPMSG device interface" + depends on RPMSG + depends on NET + help + Say Y here to export rpmsg endpoints as device files, usually found + in /dev. They make it possible for user-space programs to send and + receive rpmsg packets. + +config RPMSG_CTRL + tristate "RPMSG control interface" + depends on RPMSG && ( RPMSG_CHAR || RPMSG_CHAR=n ) + help + Say Y here to enable the support of the /dev/rpmsg_ctrlX API. This API + allows user-space programs to create endpoints with specific service name, + source and destination addresses. + +config RPMSG_NS + tristate "RPMSG name service announcement" + depends on RPMSG + help + Say Y here to enable the support of the name service announcement + channel that probes the associated RPMsg device on remote endpoint + service announcement. + +config RPMSG_MTK_SCP + tristate "MediaTek SCP" + depends on MTK_SCP + select RPMSG + help + Say y here to enable support providing communication channels to + remote processors in MediaTek platforms. + This use IPI and IPC to communicate with remote processors. + +config RPMSG_QCOM_GLINK + tristate + select RPMSG + +config RPMSG_QCOM_GLINK_RPM + tristate "Qualcomm RPM Glink driver" + select RPMSG_QCOM_GLINK + depends on HAS_IOMEM + depends on MAILBOX + help + Say y here to enable support for the GLINK RPM communication driver, + which serves as a channel for communication with the RPM in GLINK + enabled systems. + +config RPMSG_QCOM_GLINK_SMEM + tristate "Qualcomm SMEM Glink driver" + select RPMSG_QCOM_GLINK + depends on MAILBOX + depends on QCOM_SMEM + help + Say y here to enable support for the GLINK SMEM communication driver, + which provides support for using the GLINK communication protocol + over SMEM. + +config RPMSG_QCOM_SMD + tristate "Qualcomm Shared Memory Driver (SMD)" + depends on MAILBOX + depends on QCOM_SMEM + select RPMSG + help + Say y here to enable support for the Qualcomm Shared Memory Driver + providing communication channels to remote processors in Qualcomm + platforms. + +config RPMSG_VIRTIO + tristate "Virtio RPMSG bus driver" + depends on HAS_DMA + select RPMSG + select RPMSG_NS + select VIRTIO + +endmenu -- cgit v1.3.1