1// SPDX-License-Identifier: GPL-2.0-or-later
2#include <linux/rethook.h>
3#include <linux/kprobes.h>
4#include "rethook.h"
5
6void arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *regs, bool mcount)
7{
8	rh->ret_addr = regs->gprs[14];
9	rh->frame = regs->gprs[15];
10
11	/* Replace the return addr with trampoline addr */
12	regs->gprs[14] = (unsigned long)&arch_rethook_trampoline;
13}
14NOKPROBE_SYMBOL(arch_rethook_prepare);
15
16void arch_rethook_fixup_return(struct pt_regs *regs,
17			       unsigned long correct_ret_addr)
18{
19	/* Replace fake return address with real one. */
20	regs->gprs[14] = correct_ret_addr;
21}
22NOKPROBE_SYMBOL(arch_rethook_fixup_return);
23
24/*
25 * Called from arch_rethook_trampoline
26 */
27unsigned long arch_rethook_trampoline_callback(struct pt_regs *regs)
28{
29	return rethook_trampoline_handler(regs, regs->gprs[15]);
30}
31NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
32
33/* assembler function that handles the rethook must not be probed itself */
34NOKPROBE_SYMBOL(arch_rethook_trampoline);
35