xref: /openbmc/linux/arch/riscv/kernel/probes/rethook.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic return hook for riscv.
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() */
11 unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
12 {
13 	return rethook_trampoline_handler(regs, regs->s0);
14 }
15 
16 NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
17 
18 void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount)
19 {
20 	rhn->ret_addr = regs->ra;
21 	rhn->frame = regs->s0;
22 
23 	/* replace return addr with trampoline */
24 	regs->ra = (unsigned long)arch_rethook_trampoline;
25 }
26 
27 NOKPROBE_SYMBOL(arch_rethook_prepare);
28