^^&&^^

Edit File: sysc_unlinkat.stp

# unlinkat ___________________________________________________
# new function with 2.6.16
# long sys_unlinkat(int dfd, const char __user *pathname,
#	int flag)

@define _SYSCALL_UNLINKAT_NAME
%(
	name = "unlinkat"
%)

@define _SYSCALL_UNLINKAT_ARGSTR
%(
	argstr = sprintf("%s, %s, %s", dfd_str, pathname_str, flag_str)
%)

@define _SYSCALL_UNLINKAT_REGARGS
%(
	dfd = int_arg(1)
	dfd_str = _dfd_str(dfd)
	pathname = pointer_arg(2)
	pathname_str = user_string_quoted(pathname)
	flag = uint_arg(3)
	flag_str = _at_flag_str(flag)
%)

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

# dw_unlinkat _____________________________________________________

probe dw_syscall.unlinkat = kernel.function("sys_unlinkat").call ?
{
	@_SYSCALL_UNLINKAT_NAME
	dfd = __int32($dfd)
	dfd_str = _dfd_str(__int32($dfd))
	pathname = $pathname
	pathname_str = user_string_quoted($pathname)
	flag = __uint32($flag)
	flag_str = _at_flag_str(__uint32($flag))
	@_SYSCALL_UNLINKAT_ARGSTR
}
probe dw_syscall.unlinkat.return = kernel.function("sys_unlinkat").return ?
{
	@_SYSCALL_UNLINKAT_NAME
	@SYSC_RETVALSTR($return)
}

# nd_unlinkat _____________________________________________________

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

probe nd1_syscall.unlinkat = kprobe.function("sys_unlinkat") ?
{
	@_SYSCALL_UNLINKAT_NAME
	asmlinkage()
	@_SYSCALL_UNLINKAT_REGARGS
	@_SYSCALL_UNLINKAT_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.unlinkat = kprobe.function(@arch_syscall_prefix "sys_unlinkat") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_UNLINKAT_NAME
	@_SYSCALL_UNLINKAT_REGARGS
	@_SYSCALL_UNLINKAT_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.unlinkat = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_unlinkat"), @const("__NR_compat_unlinkat"))
	@_SYSCALL_UNLINKAT_NAME
	@_SYSCALL_UNLINKAT_REGARGS
	@_SYSCALL_UNLINKAT_ARGSTR
}

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

probe nd1_syscall.unlinkat.return = kprobe.function("sys_unlinkat").return ?
{
	@_SYSCALL_UNLINKAT_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 4.17+ */
probe nd2_syscall.unlinkat.return = kprobe.function(@arch_syscall_prefix "sys_unlinkat").return ?
{
	@_SYSCALL_UNLINKAT_NAME
	@SYSC_RETVALSTR(returnval())
}

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