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/message/fusion/mptdebug.h | 293 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 293 insertions(+) create mode 100644 drivers/message/fusion/mptdebug.h (limited to 'drivers/message/fusion/mptdebug.h') diff --git a/drivers/message/fusion/mptdebug.h b/drivers/message/fusion/mptdebug.h new file mode 100644 index 000000000..c281b1359 --- /dev/null +++ b/drivers/message/fusion/mptdebug.h @@ -0,0 +1,293 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/drivers/message/fusion/mptdebug.h + * For use with LSI PCI chip/adapter(s) + * running LSI Fusion MPT (Message Passing Technology) firmware. + * + * Copyright (c) 1999-2008 LSI Corporation + * (mailto:DL-MPTFusionLinux@lsi.com) + * + */ +/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/ + +#ifndef MPTDEBUG_H_INCLUDED +#define MPTDEBUG_H_INCLUDED + +/* + * debug level can be programmed on the fly via SysFS (hex values) + * + * Example: (programming for MPT_DEBUG_EVENTS on host 5) + * + * echo 8 > /sys/class/scsi_host/host5/debug_level + * + * -------------------------------------------------------- + * mpt_debug_level - command line parameter + * this allow enabling debug at driver load time (for all iocs) + * + * Example (programming for MPT_DEBUG_EVENTS) + * + * insmod mptbase.ko mpt_debug_level=8 + * + * -------------------------------------------------------- + * CONFIG_FUSION_LOGGING - enables compiling debug into driver + * this can be enabled in the driver Makefile + * + * + * -------------------------------------------------------- + * Please note most debug prints are set to logging priority = debug + * This is the lowest level, and most verbose. Please refer to manual + * pages for syslogd or syslogd-ng on how to configure this. + */ + +#define MPT_DEBUG 0x00000001 +#define MPT_DEBUG_MSG_FRAME 0x00000002 +#define MPT_DEBUG_SG 0x00000004 +#define MPT_DEBUG_EVENTS 0x00000008 +#define MPT_DEBUG_VERBOSE_EVENTS 0x00000010 +#define MPT_DEBUG_INIT 0x00000020 +#define MPT_DEBUG_EXIT 0x00000040 +#define MPT_DEBUG_FAIL 0x00000080 +#define MPT_DEBUG_TM 0x00000100 +#define MPT_DEBUG_DV 0x00000200 +#define MPT_DEBUG_REPLY 0x00000400 +#define MPT_DEBUG_HANDSHAKE 0x00000800 +#define MPT_DEBUG_CONFIG 0x00001000 +#define MPT_DEBUG_DL 0x00002000 +#define MPT_DEBUG_RESET 0x00008000 +#define MPT_DEBUG_SCSI 0x00010000 +#define MPT_DEBUG_IOCTL 0x00020000 +#define MPT_DEBUG_FC 0x00080000 +#define MPT_DEBUG_SAS 0x00100000 +#define MPT_DEBUG_SAS_WIDE 0x00200000 +#define MPT_DEBUG_36GB_MEM 0x00400000 + +/* + * CONFIG_FUSION_LOGGING - enabled in Kconfig + */ + +#ifdef CONFIG_FUSION_LOGGING +#define MPT_CHECK_LOGGING(IOC, CMD, BITS) \ +do { \ + if (IOC->debug_level & BITS) \ + CMD; \ +} while (0) +#else +#define MPT_CHECK_LOGGING(IOC, CMD, BITS) \ +do { } while (0) +#endif + + +/* + * debug macros + */ + +#define dprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG) + +#define dsgprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SG) + +#define devtprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_EVENTS) + +#define devtverboseprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_VERBOSE_EVENTS) + +#define dinitprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_INIT) + +#define dexitprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_EXIT) + +#define dfailprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_FAIL) + +#define dtmprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_TM) + +#define ddvprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_DV) + +#define dreplyprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_REPLY) + +#define dhsprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_HANDSHAKE) + +#define dcprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_CONFIG) + +#define ddlprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_DL) + +#define drsprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_RESET) + +#define dsprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SCSI) + +#define dctlprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_IOCTL) + +#define dfcprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_FC) + +#define dsasprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SAS) + +#define dsaswideprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SAS_WIDE) + +#define d36memprintk(IOC, CMD) \ + MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_36GB_MEM) + + +/* + * Verbose logging + */ +#if defined(MPT_DEBUG_VERBOSE) && defined(CONFIG_FUSION_LOGGING) +static inline void +DBG_DUMP_FW_DOWNLOAD(MPT_ADAPTER *ioc, u32 *mfp, int numfrags) +{ + int i; + + if (!(ioc->debug_level & MPT_DEBUG)) + return; + printk(KERN_DEBUG "F/W download request:\n"); + for (i=0; i < 7+numfrags*2; i++) + printk(" %08x", le32_to_cpu(mfp[i])); + printk("\n"); +} + +static inline void +DBG_DUMP_PUT_MSG_FRAME(MPT_ADAPTER *ioc, u32 *mfp) +{ + int ii, n; + + if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME)) + return; + printk(KERN_DEBUG "%s: About to Put msg frame @ %p:\n", + ioc->name, mfp); + n = ioc->req_sz/4 - 1; + while (mfp[n] == 0) + n--; + for (ii=0; ii<=n; ii++) { + if (ii && ((ii%8)==0)) + printk("\n"); + printk(" %08x", le32_to_cpu(mfp[ii])); + } + printk("\n"); +} + +static inline void +DBG_DUMP_FW_REQUEST_FRAME(MPT_ADAPTER *ioc, u32 *mfp) +{ + int i, n; + + if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME)) + return; + n = 10; + printk(KERN_INFO " "); + for (i = 0; i < n; i++) + printk(" %08x", le32_to_cpu(mfp[i])); + printk("\n"); +} + +static inline void +DBG_DUMP_REQUEST_FRAME(MPT_ADAPTER *ioc, u32 *mfp) +{ + int i, n; + + if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME)) + return; + n = 24; + for (i=0; idebug_level & MPT_DEBUG_MSG_FRAME)) + return; + n = (le32_to_cpu(mfp[0]) & 0x00FF0000) >> 16; + printk(KERN_INFO " "); + for (i=0; idebug_level & MPT_DEBUG_MSG_FRAME)) + return; + n = 3; + printk(KERN_INFO " "); + for (i=0; idebug_level & MPT_DEBUG_TM)) + return; + n = 13; + printk(KERN_DEBUG "TM_REQUEST:\n"); + for (i=0; idebug_level & MPT_DEBUG_TM)) + return; + n = (le32_to_cpu(mfp[0]) & 0x00FF0000) >> 16; + printk(KERN_DEBUG "TM_REPLY MessageLength=%d:\n", n); + for (i=0; i