Release 4.17 samples/kprobes/kprobe_example.c
/*
* NOTE: This example is works on x86 and powerpc.
* Here's a sample kernel module showing the use of kprobes to dump a
* stack trace and selected registers when _do_fork() is called.
*
* For more information on theory of operation of kprobes, see
* Documentation/kprobes.txt
*
* You will see the trace data in /var/log/messages and on the console
* whenever _do_fork() 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] = "_do_fork";
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 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_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ananth N. Mavinakayanahalli | 60 | 37.74% | 1 | 14.29% |
| Sandeepa Prabhu | 31 | 19.50% | 1 | 14.29% |
| Johannes Thumshirn | 28 | 17.61% | 1 | 14.29% |
| David Daney | 20 | 12.58% | 1 | 14.29% |
| Huang Shijie | 18 | 11.32% | 2 | 28.57% |
| Tony Lu | 2 | 1.26% | 1 | 14.29% |
| Total | 159 | 100.00% | 7 | 100.00% |
/* kprobe post_handler: called after the probed instruction is executed */
static void 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_S390
pr_info("<%s> pre_handler: p->addr, 0x%p, flags = 0x%lx\n",
p->symbol_name, p->addr, regs->flags);
#endif
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ananth N. Mavinakayanahalli | 52 | 39.10% | 1 | 14.29% |
| Sandeepa Prabhu | 23 | 17.29% | 1 | 14.29% |
| Johannes Thumshirn | 22 | 16.54% | 1 | 14.29% |
| Huang Shijie | 18 | 13.53% | 2 | 28.57% |
| David Daney | 16 | 12.03% | 1 | 14.29% |
| Tony Lu | 2 | 1.50% | 1 | 14.29% |
| Total | 133 | 100.00% | 7 | 100.00% |
/*
* 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ananth N. Mavinakayanahalli | 33 | 97.06% | 1 | 50.00% |
| Huang Shijie | 1 | 2.94% | 1 | 50.00% |
| Total | 34 | 100.00% | 2 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ananth N. Mavinakayanahalli | 66 | 97.06% | 1 | 50.00% |
| Huang Shijie | 2 | 2.94% | 1 | 50.00% |
| Total | 68 | 100.00% | 2 | 100.00% |
static void __exit kprobe_exit(void)
{
unregister_kprobe(&kp);
pr_info("kprobe at %p unregistered\n", kp.addr);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ananth N. Mavinakayanahalli | 23 | 95.83% | 1 | 50.00% |
| Huang Shijie | 1 | 4.17% | 1 | 50.00% |
| Total | 24 | 100.00% | 2 | 100.00% |
module_init(kprobe_init)
module_exit(kprobe_exit)
MODULE_LICENSE("GPL");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ananth N. Mavinakayanahalli | 271 | 55.99% | 1 | 11.11% |
| Huang Shijie | 68 | 14.05% | 3 | 33.33% |
| Sandeepa Prabhu | 54 | 11.16% | 1 | 11.11% |
| Johannes Thumshirn | 50 | 10.33% | 1 | 11.11% |
| David Daney | 36 | 7.44% | 1 | 11.11% |
| Tony Lu | 4 | 0.83% | 1 | 11.11% |
| Petr Mladek | 1 | 0.21% | 1 | 11.11% |
| Total | 484 | 100.00% | 9 | 100.00% |
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