xref: /openbmc/linux/arch/riscv/kernel/probes/rethook.c (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18) 
1*b57c2f12SBinglei Wang // SPDX-License-Identifier: GPL-2.0-only
2*b57c2f12SBinglei Wang /*
3*b57c2f12SBinglei Wang  * Generic return hook for riscv.
4*b57c2f12SBinglei Wang  */
5*b57c2f12SBinglei Wang 
6*b57c2f12SBinglei Wang #include <linux/kprobes.h>
7*b57c2f12SBinglei Wang #include <linux/rethook.h>
8*b57c2f12SBinglei Wang #include "rethook.h"
9*b57c2f12SBinglei Wang 
10*b57c2f12SBinglei Wang /* This is called from arch_rethook_trampoline() */
arch_rethook_trampoline_callback(struct pt_regs * regs)11*b57c2f12SBinglei Wang unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
12*b57c2f12SBinglei Wang {
13*b57c2f12SBinglei Wang 	return rethook_trampoline_handler(regs, regs->s0);
14*b57c2f12SBinglei Wang }
15*b57c2f12SBinglei Wang 
16*b57c2f12SBinglei Wang NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
17*b57c2f12SBinglei Wang 
arch_rethook_prepare(struct rethook_node * rhn,struct pt_regs * regs,bool mcount)18*b57c2f12SBinglei Wang void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount)
19*b57c2f12SBinglei Wang {
20*b57c2f12SBinglei Wang 	rhn->ret_addr = regs->ra;
21*b57c2f12SBinglei Wang 	rhn->frame = regs->s0;
22*b57c2f12SBinglei Wang 
23*b57c2f12SBinglei Wang 	/* replace return addr with trampoline */
24*b57c2f12SBinglei Wang 	regs->ra = (unsigned long)arch_rethook_trampoline;
25*b57c2f12SBinglei Wang }
26*b57c2f12SBinglei Wang 
27*b57c2f12SBinglei Wang NOKPROBE_SYMBOL(arch_rethook_prepare);
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