forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
127 lines
3.8 KiB
127 lines
3.8 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Here's a sample kernel module showing the use of kprobes to dump a |
|
* stack trace and selected registers when kernel_clone() is called. |
|
* |
|
* For more information on theory of operation of kprobes, see |
|
* Documentation/trace/kprobes.rst |
|
* |
|
* You will see the trace data in /var/log/messages and on the console |
|
* whenever kernel_clone() is invoked to create a new process. |
|
*/ |
|
|
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/kprobes.h> |
|
|
|
#define MAX_SYMBOL_LEN 64 |
|
static char symbol[MAX_SYMBOL_LEN] = "kernel_clone"; |
|
module_param_string(symbol, symbol, sizeof(symbol), 0644); |
|
|
|
/* For each probe you need to allocate a kprobe structure */ |
|
static struct kprobe kp = { |
|
.symbol_name = symbol, |
|
}; |
|
|
|
/* kprobe pre_handler: called just before the probed instruction is executed */ |
|
static int __kprobes handler_pre(struct kprobe *p, struct pt_regs *regs) |
|
{ |
|
#ifdef CONFIG_X86 |
|
pr_info("<%s> pre_handler: p->addr = 0x%p, ip = %lx, flags = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->ip, regs->flags); |
|
#endif |
|
#ifdef CONFIG_PPC |
|
pr_info("<%s> pre_handler: p->addr = 0x%p, nip = 0x%lx, msr = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->nip, regs->msr); |
|
#endif |
|
#ifdef CONFIG_MIPS |
|
pr_info("<%s> pre_handler: p->addr = 0x%p, epc = 0x%lx, status = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->cp0_epc, regs->cp0_status); |
|
#endif |
|
#ifdef CONFIG_ARM64 |
|
pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx," |
|
" pstate = 0x%lx\n", |
|
p->symbol_name, p->addr, (long)regs->pc, (long)regs->pstate); |
|
#endif |
|
#ifdef CONFIG_ARM |
|
pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx, cpsr = 0x%lx\n", |
|
p->symbol_name, p->addr, (long)regs->ARM_pc, (long)regs->ARM_cpsr); |
|
#endif |
|
#ifdef CONFIG_S390 |
|
pr_info("<%s> pre_handler: p->addr, 0x%p, ip = 0x%lx, flags = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->psw.addr, regs->flags); |
|
#endif |
|
|
|
/* A dump_stack() here will give a stack backtrace */ |
|
return 0; |
|
} |
|
|
|
/* kprobe post_handler: called after the probed instruction is executed */ |
|
static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs, |
|
unsigned long flags) |
|
{ |
|
#ifdef CONFIG_X86 |
|
pr_info("<%s> post_handler: p->addr = 0x%p, flags = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->flags); |
|
#endif |
|
#ifdef CONFIG_PPC |
|
pr_info("<%s> post_handler: p->addr = 0x%p, msr = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->msr); |
|
#endif |
|
#ifdef CONFIG_MIPS |
|
pr_info("<%s> post_handler: p->addr = 0x%p, status = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->cp0_status); |
|
#endif |
|
#ifdef CONFIG_ARM64 |
|
pr_info("<%s> post_handler: p->addr = 0x%p, pstate = 0x%lx\n", |
|
p->symbol_name, p->addr, (long)regs->pstate); |
|
#endif |
|
#ifdef CONFIG_ARM |
|
pr_info("<%s> post_handler: p->addr = 0x%p, cpsr = 0x%lx\n", |
|
p->symbol_name, p->addr, (long)regs->ARM_cpsr); |
|
#endif |
|
#ifdef CONFIG_S390 |
|
pr_info("<%s> pre_handler: p->addr, 0x%p, flags = 0x%lx\n", |
|
p->symbol_name, p->addr, regs->flags); |
|
#endif |
|
} |
|
|
|
/* |
|
* fault_handler: this is called if an exception is generated for any |
|
* instruction within the pre- or post-handler, or when Kprobes |
|
* single-steps the probed instruction. |
|
*/ |
|
static int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr) |
|
{ |
|
pr_info("fault_handler: p->addr = 0x%p, trap #%dn", p->addr, trapnr); |
|
/* Return 0 because we don't handle the fault. */ |
|
return 0; |
|
} |
|
/* NOKPROBE_SYMBOL() is also available */ |
|
NOKPROBE_SYMBOL(handler_fault); |
|
|
|
static int __init kprobe_init(void) |
|
{ |
|
int ret; |
|
kp.pre_handler = handler_pre; |
|
kp.post_handler = handler_post; |
|
kp.fault_handler = handler_fault; |
|
|
|
ret = register_kprobe(&kp); |
|
if (ret < 0) { |
|
pr_err("register_kprobe failed, returned %d\n", ret); |
|
return ret; |
|
} |
|
pr_info("Planted kprobe at %p\n", kp.addr); |
|
return 0; |
|
} |
|
|
|
static void __exit kprobe_exit(void) |
|
{ |
|
unregister_kprobe(&kp); |
|
pr_info("kprobe at %p unregistered\n", kp.addr); |
|
} |
|
|
|
module_init(kprobe_init) |
|
module_exit(kprobe_exit) |
|
MODULE_LICENSE("GPL");
|
|
|