^^&&^^

Edit File: sysc_swapon.stp

# swapon _____________________________________________________
#
# asmlinkage long
# sys_swapon(const char __user * specialfile,
#		int swap_flags)
#

@define _SYSCALL_SWAPON_NAME
%(
	name = "swapon"
%)

@define _SYSCALL_SWAPON_ARGSTR
%(
	argstr = sprintf("%s, %s", path, swapflags_str)
%)

@define _SYSCALL_SWAPON_REGARGS
%(
	path_uaddr = pointer_arg(1)
	path = user_string_quoted(path_uaddr)
	swapflags = int_arg(2)
	swapflags_str = _swapon_flags_str(swapflags)
%)

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

# dw_swapon _____________________________________________________

probe dw_syscall.swapon = kernel.function("sys_swapon").call ?
{
	@_SYSCALL_SWAPON_NAME
	path_uaddr = $specialfile
	path = user_string_quoted(path_uaddr)
	swapflags = __int32($swap_flags)
	swapflags_str = _swapon_flags_str(__int32($swap_flags))
	@_SYSCALL_SWAPON_ARGSTR
}
probe dw_syscall.swapon.return = kernel.function("sys_swapon").return ?
{
	@_SYSCALL_SWAPON_NAME
	@SYSC_RETVALSTR($return)
}

# nd_swapon _____________________________________________________

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

probe nd1_syscall.swapon = kprobe.function("sys_swapon") ?
{
	@_SYSCALL_SWAPON_NAME
	asmlinkage()
	@_SYSCALL_SWAPON_REGARGS
	@_SYSCALL_SWAPON_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.swapon = kprobe.function(@arch_syscall_prefix "sys_swapon") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_SWAPON_NAME
	@_SYSCALL_SWAPON_REGARGS
	@_SYSCALL_SWAPON_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.swapon = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_swapon"), @const("__NR_compat_swapon"))
	@_SYSCALL_SWAPON_NAME
	@_SYSCALL_SWAPON_REGARGS
	@_SYSCALL_SWAPON_ARGSTR
}

probe nd_syscall.swapon.return = nd1_syscall.swapon.return!, nd2_syscall.swapon.return!, tp_syscall.swapon.return
  { }

probe nd1_syscall.swapon.return = kprobe.function("sys_swapon").return ?
{
	@_SYSCALL_SWAPON_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 4.17+ */
probe nd2_syscall.swapon.return = kprobe.function(@arch_syscall_prefix "sys_swapon").return ?
{
	@_SYSCALL_SWAPON_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.swapon.return = kernel.trace("sys_exit")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_swapon"), @const("__NR_compat_swapon"))
	@_SYSCALL_SWAPON_NAME
	@SYSC_RETVALSTR($ret)
}