xref: /linux/arch/loongarch/kernel/rethook.c (revision cdd5b5a9761fd66d17586e4f4ba6588c70e640ea)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Generic return hook for LoongArch.
4  */
5 
6 #include <linux/kprobes.h>
7 #include <linux/rethook.h>
8 #include "rethook.h"
9 
10 /* This is called from arch_rethook_trampoline() */
arch_rethook_trampoline_callback(struct pt_regs * regs)11 unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
12 {
13 	return rethook_trampoline_handler(regs, 0);
14 }
15 NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
16 
arch_rethook_prepare(struct rethook_node * rhn,struct pt_regs * regs,bool mcount)17 void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount)
18 {
19 	rhn->frame = 0;
20 	rhn->ret_addr = regs->regs[1];
21 
22 	/* replace return addr with trampoline */
23 	regs->regs[1] = (unsigned long)arch_rethook_trampoline;
24 }
25 NOKPROBE_SYMBOL(arch_rethook_prepare);
26 
27 /* ASM function that handles the rethook must not be probed itself */
28 NOKPROBE_SYMBOL(arch_rethook_trampoline);
29