linux kernel - Get a function's return value in a kretprobe handler -

i want know if possible hook kretprobe on kernel function , capture it's return value in return handler of kretprobe.

it's little bit old question, still looking answer..

how register kretprobe can see in documentation kprobes (https://www.kernel.org/doc/documentation/kprobes.txt)

an architecture independent function captures ret value syscalls:

#include <linux/ptrace.h>  ...  int hook_retcode(struct kretprobe_instance *ri, struct pt_regs *regs) {     unsigned long retval = 0;      retval = regs_return_value(regs);      if (is_syscall_success(regs))     {         printk("%pf exited code %#lx\n", ri->rp->kp.addr, retval);     }     else     {         printk("%pf failed code %#lx\n", ri->rp->kp.addr, retval);     } }