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Filename : sysc_semget.stp
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# semget _____________________________________________________
# long sys_semget (key_t key, int nsems, int semflg)
#

@define _SYSCALL_SEMGET_NAME
%(
	name = "semget"
%)

@define _SYSCALL_SEMGET_ARGSTR
%(
	argstr = sprintf("%s, %d, %s", key_str, nsems, semflg_str)
%)

@define _SYSCALL_SEMGET_REGARGS
%(
	key = int_arg(1)
	key_str = _stp_msgget_key_str(key)
	nsems = int_arg(2)
	semflg = int_arg(3)
	semflg_str = __sem_flags(semflg)
%)

@define _SYSCALL_IPC_SEMGET_REGARGS
%(
	key = int_arg(2)
	key_str = _stp_msgget_key_str(key)
	nsems = int_arg(3)
	semflg = int_arg(4)
	semflg_str = __sem_flags(semflg)
%)

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

# dw_semget _____________________________________________________

probe dw_syscall.semget = kernel.function("sys_semget").call ?
{
	@_SYSCALL_SEMGET_NAME
	key = __int32($key)
	key_str = _stp_msgget_key_str(__int32($key))
	nsems = __int32($nsems)
	semflg = __int32($semflg)
	semflg_str = __sem_flags(__int32($semflg))
	@_SYSCALL_SEMGET_ARGSTR
}
probe dw_syscall.semget.return = kernel.function("sys_semget").return ?
{
	@_SYSCALL_SEMGET_NAME
	@SYSC_RETVALSTR($return)
}

# nd_semget _____________________________________________________

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

probe nd1_syscall.semget = kprobe.function("sys_semget") ?
{
	@_SYSCALL_SEMGET_NAME
	asmlinkage()
	@_SYSCALL_SEMGET_REGARGS
	@_SYSCALL_SEMGET_ARGSTR
}

/* kernel 4.17+ */
probe nd2_syscall.semget =
	__nd2_syscall.semget ?,
	__nd2_syscall.compat_ipc.semget ?
{
	@_SYSCALL_SEMGET_NAME
	@_SYSCALL_SEMGET_ARGSTR
}
probe __nd2_syscall.semget =
	kprobe.function(@arch_syscall_prefix "sys_semget") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_SEMGET_REGARGS
}
probe __nd2_syscall.compat_ipc.semget =
	kprobe.function(@arch_syscall_prefix "compat_sys_ipc") ?
{
	__set_syscall_pt_regs(pointer_arg(1))
	if (int_arg(1) != @const("SEMGET")) next;
	@_SYSCALL_IPC_SEMGET_REGARGS
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.semget =
	__tp_syscall.semget ?,
	__tp_syscall.compat_ipc.semget ?
{
	@_SYSCALL_SEMGET_NAME
	@_SYSCALL_SEMGET_ARGSTR
}
probe __tp_syscall.semget = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__syscall_gate(@const("__NR_semget"))
	@_SYSCALL_SEMGET_REGARGS
}
probe __tp_syscall.compat_ipc.semget = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__compat_syscall_gate(@const("__NR_compat_ipc"))
	if (int_arg(1) != @const("SEMGET")) next;
	@_SYSCALL_IPC_SEMGET_REGARGS
}

probe nd_syscall.semget.return = nd1_syscall.semget.return!, nd2_syscall.semget.return!, tp_syscall.semget.return
  { }
  
probe nd1_syscall.semget.return = kprobe.function("sys_semget").return ?
{
	@_SYSCALL_SEMGET_NAME
	@SYSC_RETVALSTR(returnval())
}

/* kernel 4.17+ */
probe nd2_syscall.semget.return =
	kprobe.function(@arch_syscall_prefix "sys_semget").return ?,
	__nd2_syscall.compat_ipc.semget.return ?
{
	@_SYSCALL_SEMGET_NAME
	@SYSC_RETVALSTR(returnval())
}
probe __nd2_syscall.compat_ipc.semget.return =
	kprobe.function(@arch_syscall_prefix "compat_sys_ipc").return ?
{
	__set_syscall_pt_regs(@entry(pointer_arg(1)))
	if (int_arg(1) != @const("SEMGET")) next;
}
 
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.semget.return =
	__tp_syscall.semget.return ?,
	__tp_syscall.compat_ipc.semget.return ?
{
	@_SYSCALL_SEMGET_NAME
	@SYSC_RETVALSTR($ret)
}
probe __tp_syscall.semget.return = kernel.trace("sys_exit")
{
	@__syscall_gate(@const("__NR_semget"))
}
probe __tp_syscall.compat_ipc.semget.return = kernel.trace("sys_exit")
{
	__set_syscall_pt_regs($regs)
	@__compat_syscall_gate(@const("__NR_compat_ipc"))
	if (int_arg(1) != @const("SEMGET")) next;
}