^^&&^^

Edit File: sysc_chroot.stp

# chroot _____________________________________________________
# long sys_chroot(const char __user * filename)

@define _SYSCALL_CHROOT_NAME
%(
	name = "chroot"
%)

@define _SYSCALL_CHROOT_ARGSTR
%(
	argstr = path
%)

@define _SYSCALL_CHROOT_REGARGS
%(
	path = user_string_quoted(pointer_arg(1))
%)

probe syscall.chroot = dw_syscall.chroot !, nd_syscall.chroot ? {}
probe syscall.chroot.return = dw_syscall.chroot.return !, nd_syscall.chroot.return ? {}

# dw_chroot _____________________________________________________

probe dw_syscall.chroot = kernel.function("sys_chroot").call
{
	@_SYSCALL_CHROOT_NAME
	path = user_string_quoted($filename)
	@_SYSCALL_CHROOT_ARGSTR
}
probe dw_syscall.chroot.return = kernel.function("sys_chroot").return
{
	@_SYSCALL_CHROOT_NAME
	@SYSC_RETVALSTR($return)
}

# nd_chroot _____________________________________________________

probe nd_syscall.chroot = nd1_syscall.chroot!, nd2_syscall.chroot!, tp_syscall.chroot
  { }

probe nd1_syscall.chroot = kprobe.function("sys_chroot") ?
{
	@_SYSCALL_CHROOT_NAME
	asmlinkage()
	@_SYSCALL_CHROOT_REGARGS
	@_SYSCALL_CHROOT_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.chroot = kprobe.function(@arch_syscall_prefix "sys_chroot") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_CHROOT_NAME
	@_SYSCALL_CHROOT_REGARGS
	@_SYSCALL_CHROOT_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.chroot = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_chroot"), @const("__NR_compat_chroot"))
	@_SYSCALL_CHROOT_NAME
	@_SYSCALL_CHROOT_REGARGS
	@_SYSCALL_CHROOT_ARGSTR
}

probe nd_syscall.chroot.return = nd1_syscall.chroot.return!, nd2_syscall.chroot.return!, tp_syscall.chroot.return
  { }
  
probe nd1_syscall.chroot.return = kprobe.function("sys_chroot").return ?
{
	@_SYSCALL_CHROOT_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 4.17+ */
probe nd2_syscall.chroot.return = kprobe.function(@arch_syscall_prefix "sys_chroot").return ?
{
	@_SYSCALL_CHROOT_NAME
	@SYSC_RETVALSTR(returnval())
}
 
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.chroot.return = kernel.trace("sys_exit")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_chroot"), @const("__NR_compat_chroot"))
	@_SYSCALL_CHROOT_NAME
	@SYSC_RETVALSTR($ret)
}