2002-09-30 01:07:05

by omit_ECE

[permalink] [raw]
Subject: [email protected]

Hi,

I want to know the one-way trip time in TCP header.
In tcp_input.c , I found many functions under which include
rcv_tsval and rcv_tsecr . I don't know which two are right.
So, I put many "printf" and fprintf in functions and compile the kernel.
But when compiling it, some errors happen,

net/network.o: In function `tcp_parse_options':
net/network.o: In function `tcp_rcv_established':
net/network.o: In function `tcp_rcv_synsent_state_process':
net/network.o: In function `tcp_rcv_state_process':
net/network.o(.text+0x2807b): undefined reference to `printf'
net/network.o(.text+0x2808c): undefined reference to `printf'
net/network.o(.text+0x2631d): undefined reference to `fopen'
net/network.o(.text+0x26334): undefined reference to `fprintf'
net/network.o(.text+0x2634e): undefined reference to `fprintf'
net/network.o(.text+0x2635a): undefined reference to `fclose'

Aren't "printf" and "fprintf" standard outputs? I also put #include <stdio.h>
and "FILE *in_file", but they didn't work. Please give me suggestions.
Thank you.


2002-09-30 01:20:01

by David Miller

[permalink] [raw]
Subject: Re: [email protected]

From: "omit_ECE" <[email protected]>
Date: Sun, 29 Sep 2002 20:13:56 -0500

Aren't "printf" and "fprintf" standard outputs?

There is not standard output in the kernel, and you can't assume
libc facilities are all available.

Use "printk" available from linux/kernel.h instead.

2002-09-30 01:35:33

by Jeff Chua

[permalink] [raw]
Subject: Re: [email protected]

On Sun, 29 Sep 2002, omit_ECE wrote:
>
> Aren't "printf" and "fprintf" standard outputs? I also put #include <stdio.h>
> and "FILE *in_file", but they didn't work. Please give me suggestions.

try printk instead.

Jeff