^^&&^^

Edit File: sysc_fchown.stp

# fchown _____________________________________________________
# long sys_fchown(unsigned int fd, uid_t user, gid_t group)

@define _SYSCALL_FCHOWN_NAME
%(
	name = "fchown"
%)

@define _SYSCALL_FCHOWN_ARGSTR
%(
	argstr = sprintf("%d, %d, %d", fd, owner, group)
%)

@define _SYSCALL_FCHOWN_REGARGS
%(
	fd = int_arg(1)
	owner = __int32(uint_arg(2))
	group = __int32(uint_arg(3))
%)

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

# dw_fchown _____________________________________________________

probe dw_syscall.fchown = kernel.function("sys_fchown").call
{
	// Avoid fchown16() calling fchown().
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_fchown"), @const("__NR_ia32_fchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_fchown32"))
%)
	@_SYSCALL_FCHOWN_NAME
	fd = __int32($fd)
	owner = __int32($user)
	group = __int32($group)
	@_SYSCALL_FCHOWN_ARGSTR
}
probe dw_syscall.fchown.return = kernel.function("sys_fchown").return
{
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_fchown"), @const("__NR_ia32_fchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_fchown32"))
%)
	@_SYSCALL_FCHOWN_NAME
	@SYSC_RETVALSTR($return)
}

# nd_fchown _____________________________________________________

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

probe nd1_syscall.fchown = kprobe.function("sys_fchown") ?
{
	// Avoid fchown16() calling fchown().
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_fchown"), @const("__NR_ia32_fchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_fchown32"))
%)
	@_SYSCALL_FCHOWN_NAME
	asmlinkage()
	@_SYSCALL_FCHOWN_REGARGS
	@_SYSCALL_FCHOWN_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.fchown = kprobe.function(@arch_syscall_prefix "sys_fchown") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_FCHOWN_NAME
	@_SYSCALL_FCHOWN_REGARGS
	@_SYSCALL_FCHOWN_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.fchown = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
%( CONFIG_64BIT == "y" %?
	@__syscall_compat_gate(@const("__NR_fchown"), @const("__NR_compat_fchown32"))
%:
	@__syscall_gate(@const("__NR_fchown32"))
%)
	@_SYSCALL_FCHOWN_NAME
	@_SYSCALL_FCHOWN_REGARGS
	@_SYSCALL_FCHOWN_ARGSTR
}

probe nd_syscall.fchown.return = nd1_syscall.fchown.return!, nd2_syscall.fchown.return!, tp_syscall.fchown.return
  { }
  
probe nd1_syscall.fchown.return = kprobe.function("sys_fchown").return ?
{
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_fchown"), @const("__NR_ia32_fchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_fchown32"))
%)
	@_SYSCALL_FCHOWN_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 4.17+ */
probe nd2_syscall.fchown.return = kprobe.function(@arch_syscall_prefix "sys_fchown").return ?
{
	@_SYSCALL_FCHOWN_NAME
	@SYSC_RETVALSTR(returnval())
}
 
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.fchown.return = kernel.trace("sys_exit")
{
	__set_syscall_pt_regs($regs)
%( CONFIG_64BIT == "y" %?
	@__syscall_compat_gate(@const("__NR_fchown"), @const("__NR_compat_fchown32"))
%:
	@__syscall_gate(@const("__NR_fchown32"))
%)
	@_SYSCALL_FCHOWN_NAME
	@SYSC_RETVALSTR($ret)
}