Contributors: 10
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Masami Hiramatsu |
203 |
70.73% |
18 |
58.06% |
| Steven Rostedt |
41 |
14.29% |
3 |
9.68% |
| Prasanna S. Panchamukhi |
16 |
5.57% |
2 |
6.45% |
| Stephen Brennan |
8 |
2.79% |
1 |
3.23% |
| Ananth N. Mavinakayanahalli |
6 |
2.09% |
2 |
6.45% |
| Christoph Lameter |
4 |
1.39% |
1 |
3.23% |
| Andi Kleen |
3 |
1.05% |
1 |
3.23% |
| Quentin Barnes |
3 |
1.05% |
1 |
3.23% |
| Thomas Gleixner |
2 |
0.70% |
1 |
3.23% |
| Ingo Molnar |
1 |
0.35% |
1 |
3.23% |
| Total |
287 |
|
31 |
|
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Dynamic Ftrace based Kprobes Optimization
*
* Copyright (C) Hitachi Ltd., 2012
*/
#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/hardirq.h>
#include <linux/preempt.h>
#include <linux/ftrace.h>
#include <asm/text-patching.h>
#include "common.h"
/* Ftrace callback handler for kprobes -- called under preempt disabled */
void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
struct pt_regs *regs = ftrace_get_regs(fregs);
struct kprobe *p;
struct kprobe_ctlblk *kcb;
int bit;
if (unlikely(kprobe_ftrace_disabled))
return;
bit = ftrace_test_recursion_trylock(ip, parent_ip);
if (bit < 0)
return;
p = get_kprobe((kprobe_opcode_t *)ip);
if (unlikely(!p) || kprobe_disabled(p))
goto out;
kcb = get_kprobe_ctlblk();
if (kprobe_running()) {
kprobes_inc_nmissed_count(p);
} else {
unsigned long orig_ip = instruction_pointer(regs);
/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
instruction_pointer_set(regs, ip + INT3_INSN_SIZE);
__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (!p->pre_handler || !p->pre_handler(p, regs)) {
if (unlikely(p->post_handler)) {
/*
* Emulate singlestep (and also recover regs->ip)
* as if there is a 5byte nop
*/
instruction_pointer_set(regs, ip + MCOUNT_INSN_SIZE);
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
}
/* Recover IP address */
instruction_pointer_set(regs, orig_ip);
}
/*
* If pre_handler returns !0, it changes regs->ip. We have to
* skip emulating post_handler.
*/
__this_cpu_write(current_kprobe, NULL);
}
out:
ftrace_test_recursion_unlock(bit);
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);
int arch_prepare_kprobe_ftrace(struct kprobe *p)
{
p->ainsn.insn = NULL;
p->ainsn.boostable = false;
return 0;
}