^^&&^^

Edit File: sysc_lchown.stp

# lchown _____________________________________________________
# long sys_lchown(const char __user * filename, uid_t user, gid_t group)
#

@define _SYSCALL_LCHOWN_NAME
%(
	name = "lchown"
%)

@define _SYSCALL_LCHOWN_ARGSTR
%(
	argstr = sprintf("%s, %d, %d", path, owner, group)
%)

@define _SYSCALL_LCHOWN_REGARGS
%(
	path = user_string_quoted(pointer_arg(1))
	owner = __int32(uint_arg(2))
	group = __int32(uint_arg(3))
%)

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

# dw_lchown _____________________________________________________

probe dw_syscall.lchown = kernel.function("sys_lchown").call
{
	// Avoid lchown16() calling lchown().
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_lchown"), @const("__NR_ia32_lchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_lchown32"))
%)
	@_SYSCALL_LCHOWN_NAME
	path = user_string_quoted($filename)
	owner = __int32($user)
	group = __int32($group)
	@_SYSCALL_LCHOWN_ARGSTR
}
probe dw_syscall.lchown.return = kernel.function("sys_lchown").return
{
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_lchown"), @const("__NR_ia32_lchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_lchown32"))
%)
	@_SYSCALL_LCHOWN_NAME
	@SYSC_RETVALSTR($return)
}

# nd_lchown _____________________________________________________

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

probe nd1_syscall.lchown = kprobe.function("sys_lchown") ?
{
	// Avoid lchown16() calling lchown().
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_lchown"), @const("__NR_ia32_lchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_lchown32"))
%)
	@_SYSCALL_LCHOWN_NAME
	asmlinkage()
	@_SYSCALL_LCHOWN_REGARGS
	@_SYSCALL_LCHOWN_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.lchown = kprobe.function(@arch_syscall_prefix "sys_lchown") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_LCHOWN_NAME
	@_SYSCALL_LCHOWN_REGARGS
	@_SYSCALL_LCHOWN_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.lchown = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
%( CONFIG_64BIT == "y" %?
	@__syscall_compat_gate(@const("__NR_lchown"), @const("__NR_compat_lchown32"))
%:
	@__syscall_gate(@const("__NR_lchown32"))
%)
	@_SYSCALL_LCHOWN_NAME
	@_SYSCALL_LCHOWN_REGARGS
	@_SYSCALL_LCHOWN_ARGSTR
}

probe nd_syscall.lchown.return = nd1_syscall.lchown.return!, nd2_syscall.lchown.return!, tp_syscall.lchown.return
  { }
  
probe nd1_syscall.lchown.return = kprobe.function("sys_lchown").return ?
{
%( arch == "x86_64" %?
	@__syscall_compat_gate(@const("__NR_lchown"), @const("__NR_ia32_lchown32"))
%)
%( arch == "i386" %?
	@__syscall_gate(@const("__NR_lchown32"))
%)
	@_SYSCALL_LCHOWN_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 4.17+ */
probe nd2_syscall.lchown.return = kprobe.function(@arch_syscall_prefix "sys_lchown").return ?
{
	@_SYSCALL_LCHOWN_NAME
	@SYSC_RETVALSTR(returnval())
}
 
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.lchown.return = kernel.trace("sys_exit")
{
	__set_syscall_pt_regs($regs)
%( CONFIG_64BIT == "y" %?
	@__syscall_compat_gate(@const("__NR_lchown"), @const("__NR_compat_lchown32"))
%:
	@__syscall_gate(@const("__NR_lchown32"))
%)
	@_SYSCALL_LCHOWN_NAME
	@SYSC_RETVALSTR($ret)
}