^^&&^^

Edit File: sysc_fchmod.stp

# fchmod _____________________________________________________
# long sys_fchmod(unsigned int fd, mode_t mode)

@define _SYSCALL_FCHMOD_NAME
%(
	name = "fchmod"
%)

@define _SYSCALL_FCHMOD_ARGSTR
%(
	argstr = sprintf("%d, %#o", fildes, mode)
%)

@define _SYSCALL_FCHMOD_REGARGS
%(
	fildes = int_arg(1)
	mode = uint_arg(2)
%)

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

# dw_fchmod _____________________________________________________

probe dw_syscall.fchmod = kernel.function("sys_fchmod").call
{
	@_SYSCALL_FCHMOD_NAME
	fildes = __int32($fd)
%( arch == "i386" %?
	# Why @cast() here? Even though the user passes an unsigned
	# int (32-bits), some kernels (2.6.32-431.el6.i686) get an
	# unsigned short (16-bits).
	mode = @uint_cast(&$mode)
%:
	mode = __uint32($mode)
%)
	@_SYSCALL_FCHMOD_ARGSTR
}
probe dw_syscall.fchmod.return = kernel.function("sys_fchmod").return
{
	@_SYSCALL_FCHMOD_NAME
	@SYSC_RETVALSTR($return)
}

# nd_fchmod _____________________________________________________

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

probe nd1_syscall.fchmod = kprobe.function("sys_fchmod") ?
{
	@_SYSCALL_FCHMOD_NAME
	asmlinkage()
	@_SYSCALL_FCHMOD_REGARGS
	@_SYSCALL_FCHMOD_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.fchmod = kprobe.function(@arch_syscall_prefix "sys_fchmod") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_FCHMOD_NAME
	@_SYSCALL_FCHMOD_REGARGS
	@_SYSCALL_FCHMOD_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.fchmod = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_fchmod"), @const("__NR_compat_fchmod"))
	@_SYSCALL_FCHMOD_NAME
	@_SYSCALL_FCHMOD_REGARGS
	@_SYSCALL_FCHMOD_ARGSTR
}

probe nd_syscall.fchmod.return = nd1_syscall.fchmod.return!, nd2_syscall.fchmod.return!, tp_syscall.fchmod.return
  { }
  
probe nd1_syscall.fchmod.return = kprobe.function("sys_fchmod").return ?
{
	@_SYSCALL_FCHMOD_NAME
	@SYSC_RETVALSTR(returnval())
}

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