1 // SPDX-License-Identifier: GPL-2.0-or-later
2 #include <linux/rethook.h>
3 #include <linux/kprobes.h>
4 #include "rethook.h"
5 
arch_rethook_prepare(struct rethook_node * rh,struct pt_regs * regs,bool mcount)6 void 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 }
14 NOKPROBE_SYMBOL(arch_rethook_prepare);
15 
arch_rethook_fixup_return(struct pt_regs * regs,unsigned long correct_ret_addr)16 void 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 }
22 NOKPROBE_SYMBOL(arch_rethook_fixup_return);
23 
24 /*
25  * Called from arch_rethook_trampoline
26  */
arch_rethook_trampoline_callback(struct pt_regs * regs)27 unsigned long arch_rethook_trampoline_callback(struct pt_regs *regs)
28 {
29 	return rethook_trampoline_handler(regs, regs->gprs[15]);
30 }
31 NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
32 
33 /* assembler function that handles the rethook must not be probed itself */
34 NOKPROBE_SYMBOL(arch_rethook_trampoline);
35