SYSCALL_SET_RETURN_V(9) Machine State SYSCALL_SET_RETURN_V(9)NAMEsyscall_set_return_value - change the return value of a traced system
call
SYNOPSIS
void syscall_set_return_value(struct task_struct * task,
struct pt_regs * regs, int error,
long val);
ARGUMENTS
task
task of interest, must be blocked
regs
task_pt_regs of task
error
negative error code, or zero to indicate success
val
user return value if error is zero
DESCRIPTION
This changes the results of the system call that user mode will see. If
error is zero, the user sees a successful system call with a return
value of val. If error is nonzero, it´s a negated errno code; the user
sees a failed system call with this errno code.
It´s only valid to call this when task is stopped for tracing on exit
from a system call, due to TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT.
Kernel Hackers Manual 2.6. November 2013 SYSCALL_SET_RETURN_V(9)