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Filename : sysc_read.stp
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# read _______________________________________________________
# ssize_t sys_read(unsigned int fd, char __user * buf, size_t count)

@define _SYSCALL_READ_NAME
%(
	name = "read"
%)

@define _SYSCALL_READ_ARGSTR
%(
	argstr = sprintf("%d, %p, %u", fd, buf_uaddr, count)
%)


@define _SYSCALL_READ_REGARGS
%(
	fd = int_arg(1)
	buf_uaddr = pointer_arg(2)
	count = ulong_arg(3)
%)

probe syscall.read = dw_syscall.read !, nd_syscall.read { }
probe syscall.read.return = dw_syscall.read.return !, nd_syscall.read.return {}

# dw_read _____________________________________________________

probe dw_syscall.read =
%( arch == "s390" %?
	__syscall.read, kernel.function("sys32_read").call ?,
	kernel.function("compat_sys_s390_read").call ?
%:
	__syscall.read
%)
{
	@_SYSCALL_READ_NAME
	fd = __int32($fd)
	buf_uaddr = @__pointer($buf)
	count = @__compat_ulong($count)
	@_SYSCALL_READ_ARGSTR
}
probe __syscall.read = kernel.function("sys_read").call
{
%( arch == "s390" %?
	@__syscall_gate(@const("__NR_read"))
%)
}
probe dw_syscall.read.return =
%( arch == "s390" %?
	__syscall.read.return, kernel.function("sys32_read").return ?,
	kernel.function("compat_sys_s390_read").return ?
%:
	__syscall.read.return
%)
{
	@_SYSCALL_READ_NAME
	@SYSC_RETVALSTR($return)
}
probe __syscall.read.return = kernel.function("sys_read").return
{
%( arch == "s390" %?
	@__syscall_gate(@const("__NR_read"))
%)
}

# nd_read _____________________________________________________

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

probe nd1_syscall.read =  
%( arch == "s390" %?
	__nd1_syscall.read, kprobe.function("sys32_read") ?,
	kprobe.function("compat_sys_s390_read") ?
%:
	__nd1_syscall.read
%)
{
	@_SYSCALL_READ_NAME
        asmlinkage()
	@_SYSCALL_READ_REGARGS
	@_SYSCALL_READ_ARGSTR
}
  
probe __nd1_syscall.read = kprobe.function("sys_read")
{
%( arch == "s390" %?
	@__syscall_gate(@const("__NR_read"))
%)
}

/* kernel 4.17+ */
probe nd2_syscall.read = kprobe.function(@arch_syscall_prefix "sys_read")
{
	__set_syscall_pt_regs(pointer_arg(1))
	@_SYSCALL_READ_NAME
	@_SYSCALL_READ_REGARGS
	@_SYSCALL_READ_ARGSTR
}

/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.read = kernel.trace("sys_enter")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_read"), @const("__NR_compat_read"))
	@_SYSCALL_READ_NAME
	@_SYSCALL_READ_REGARGS
	@_SYSCALL_READ_ARGSTR
}

probe nd_syscall.read.return = nd1_syscall.read.return!, nd2_syscall.read.return!, tp_syscall.read.return
  { }
  
probe nd1_syscall.read.return =
%( arch == "s390" %?
	__nd1_syscall.read.return, kprobe.function("sys32_read").return ?,
	kprobe.function("compat_sys_s390_read").return ?
%:
	__nd1_syscall.read.return
%)
{
	@_SYSCALL_READ_NAME
	@SYSC_RETVALSTR(returnval())
}
probe __nd1_syscall.read.return = kprobe.function("sys_read").return
{
%( arch == "s390" %?
	@__syscall_gate(@const("__NR_read"))
%)
}

/* kernel 4.17+ */
probe nd2_syscall.read.return = kprobe.function(@arch_syscall_prefix "sys_read").return
{
	@_SYSCALL_READ_NAME
	@SYSC_RETVALSTR(returnval())
}
 
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.read.return = kernel.trace("sys_exit")
{
	__set_syscall_pt_regs($regs)
	@__syscall_compat_gate(@const("__NR_read"), @const("__NR_compat_read"))
	@_SYSCALL_READ_NAME
	@SYSC_RETVALSTR($ret)
}