Linux-Development-Sys Digest #594, Volume #8 Wed, 28 Mar 01 16:13:13 EST
Contents:
3c59x.c 'debug' question ("Jim Fischer")
Re: Parallel Port (Kasper Dupont)
broadcast detection (Marko Friedemann)
Re: computer input/output devices (Nix)
Re: 0-order allocation failed on 2.4.2 (Ed Clarke)
Re: C++ and shell (Giovanni Meneghetti)
Re: Redirect boot.msg ([EMAIL PROTECTED])
Re: problem with put_user for char device (V2.2.17 kernel). ("curmudgeon")
How to call a function and don't wait for return ("tlin")
Re: C++ and shell (Phil Ehrens)
Re: uart (Markus Kossmann)
Re: How to call a function and don't wait for return ([EMAIL PROTECTED])
compile kernel error ("Astroboy")
Realtime programming (Josef Allen)
Re: uart (Josef Allen)
interaction userspace with kernel ([EMAIL PROTECTED])
Re: compile kernel error (Kasper Dupont)
Re: can any one suggest the editor for linux,other than vi, which is similar to
Editor for Windows..... ("Osiris Pedroso")
----------------------------------------------------------------------------
From: "Jim Fischer" <[EMAIL PROTECTED]>
Subject: 3c59x.c 'debug' question
Date: Wed, 28 Mar 2001 04:25:07 -0800
In the Linux 2.4.2 source tree, the following lines of code appear in
linux/drivers/net/3c59x.c starting at about line 170:
<begin>
/* Put out somewhat more debugging messages. (0: no msg, 1 minimal .. 6). */
#define vortex_debug debug
#ifdef VORTEX_DEBUG
static int vortex_debug = VORTEX_DEBUG;
#else
static int vortex_debug = 1;
#endif
<end>
My question is this: what the heck is the #define line for ??? It seems to
me that it does nothing useful since the #ifdef-#else-#endif macros are
guaranteed <?> to (re)define the identifier 'vortex_debug' regardless of
whether the #define exists or not.
Also, I'm curious about the identifier 'debug'. Where does it come from,
what's its purpose, how is it used [e.g., an insmod option?], etc. Tks...
Jim
------------------------------
From: Kasper Dupont <[EMAIL PROTECTED]>
Subject: Re: Parallel Port
Date: Wed, 28 Mar 2001 13:55:15 +0000
Jan Pietrusky wrote:
>
> Hello,
> how can I read and write values to or from the parallel port in user
> mode. If I'm root, I can use the write(), but read() failed. Why? I use
> /dev/port and I use open().
>
> Thanks Jan
> --
I suggest you use ioperm() and the inb() and outb()
macros. See the IO-Port-Programming mini howto for
code examples.
--
Kasper Dupont
------------------------------
From: Marko Friedemann <[EMAIL PROTECTED]>
Subject: broadcast detection
Date: Wed, 28 Mar 2001 16:34:51 +0200
hey guys,
recently I encountered a problem while trying to install a sun4u via
network (boot net:arp) with redhat-linux 7.0 as tftpd+rarpd+bootparamd
server and another sun in some remote subnet as nfs server for the
filesystem.
to reduce it a little, after getting the installation kernel from the
other sun, there is another broadcast for bootparamd. but although it is
running and listening on the linux machine sitting just 3 feet away,
there is no answer and the sun goes into an endless loop.
i did some researching and finally found the following: the offending
net infrastructure has a type B network adress. It is, however,
partitioned into subnets having class C broadcast adresses. Because the
sun4u boot parameter detection does only ask for IP and internally
calculates the broadcast address as class B (wrong), the linux machine
does not answer the request.
the configuration is the following:
linux: 134.xxx.184.205 -> 134.xxx.184.255
sun4u: 134.xxx.184.204 -> wrong guess to 134.xxx.255.255
result:
broadcast packet to 134.xxx.255.255 not recognized by linux machine.
I further investigated the problem. i tried the original rh kernel
(2.2.14) and 2.4.0. then I installed an older suse (version 5.3) with
kernel 2.0.35. This was known to work and in fact it did. it answered
the request. i then updated the suse distro to be able to try 2.2.18.
and voila, the suse now failed to answer the request, too.
If, however, I temporarily change the linux machine's broadcast address
to 134.xxx.255.255 then it works fine with 2.2.18 and 2.4.0.
I therefore assume it must have been a change in between 2.0.x and 2.2.x
that altered the behavior of detecting broadcasts.
Since I got insterested, I digged a bit around in the 2.4.2 sourcecode
and it seems the problem arises from fn_hash_lookup()
(net/ipv4/fib_hash.c) not finding the address inside the hash table.
what I'm missing is where that table is actually filled,
fn_hash_insert() (net/ipv4/fib_hash.c) is obviously not used for that
purpose, because it simply calls BUG().
My main concern is whether the change had anything to do with a security
issue or just slipped by as an undetected flaw. I tried to find some
useful information in the rfc database but failed on that.
I hope someone can provide me with some helpful information,
regards
Marko Friedemann
--
www.bmx-chemnitz.de -==- 20 Zoll in Chemnitz
[EMAIL PROTECTED]
------------------------------
From: Nix <$}xinix{$@esperi.demon.co.uk>
Subject: Re: computer input/output devices
Date: 28 Mar 2001 08:16:15 +0100
On Tue, 27 Mar 2001, carla said:
> I would like to know the definition and history of the different
> input /output devices of the computer
`I would like someone to do my homework for me.'
Warning: it is not unknown for the person who *set* that homework to
read groups like this one.
--
`I've had my name crash computers. My name is a Word of Power.'
--- Peter da Silva
------------------------------
From: [EMAIL PROTECTED] (Ed Clarke)
Subject: Re: 0-order allocation failed on 2.4.2
Date: Wed, 28 Mar 2001 14:41:18 +0000 (UTC)
On Tue, 27 Mar 2001 23:17:07 -0800, David Gray <[EMAIL PROTECTED]> wrote:
>This means the kernel wasn't able to allocate any pages to satisfy
>your request - that is, you ran out of kernel memory. The 0 probably
>comes from get_zeroed_page() which calls alloc_pages() with an order
>value of 0, this in turn eventually gets to __alloc_pages() which tries
>really hard to allocate what you asked for in terms of a working set of
>pages but can't. It looks like the swapper is woken up in order to swap
>out whatever it can to make memory available, in your case, that didn't
>work either.
>
>How much RAM and how much swap do you have?
Two gigabytes of swap space and 1300 meg of RAM (1024meg + 256meg).
As far as I can tell from the source, allocation fails, puts out a
kernel message and returns a null (why in Gods name is cat trying
to allocate that much RAM?????). Is this going to bite me in the
rear later on? The cat program finished with seeming success (I did
an md5sum on it to check against the original file).
My test is as follows:
cat part1 part2 part3 part4 part5 part6 > canonball.mpg
Where part 1-5 are each 500000000 bytes long and part6 is 441092680
bytes long. (Stupidly huge file and an even worse movie IMHO). I
had been getting solid filesystem destroying crashes with the raw
2.4.0/2.4.2 sources from ftp.us.kernel.org. I just took the 2.4.2
source from rawhide.redhat.com and compiled that instead ( they have
a lot of patches to 2.4.2 ). No more crashes (yet) but this worrying
allocation error in dmesg and /var/log/messages.
------------------------------
From: Giovanni Meneghetti <[EMAIL PROTECTED]>
Subject: Re: C++ and shell
Date: Wed, 28 Mar 2001 17:04:15 +0200
You have to dup the stdout to a file descriptor, the fork, then exec.
If you need an example, I may send you one of my old works.
Bye
Giovanni Meneghetti
FLD wrote:
> I'm making a GUI for a command line tool i often use. til now i've used
> the "system" command which works fine, but i'm now interested in getting
> the tool output (text) in my program. How can i make it work ?
>
> FLD
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: Redirect boot.msg
Date: Wed, 28 Mar 2001 08:09:13 -0700
You may need "console=ttyS0,115200" (or whatever baud rate you are using) if your
serial line is running at other than 9600.
Kasper Dupont wrote:
> Meg Chan wrote:
> >
> > How can i redirect the output on system startup (which is saved to boot.msg)
> > from tty0 to ttyS0? I'm using a serial terminal and want to see all the boot
> > messages on it. Adding the "console" parameter to lilo only causes to print
> > "Loading linux........" on ttyS0. But i want to get the rest there too.
>
> This works for me:
> append = "console=ttyS0"
>
> I presume you are using the serial parameter,
> which redirects all the output from LILO but
> not from the kernel. The console parameter
> OTOH only redirects output from the kernel,
> not from LILO. So you probably need to
> specify both.
>
> --
> Kasper Dupont
------------------------------
From: "curmudgeon" <[EMAIL PROTECTED]>
Subject: Re: problem with put_user for char device (V2.2.17 kernel).
Date: Wed, 28 Mar 2001 10:23:18 -0500
Yes, the problem was the omission of the -O2 flag in the compiler options
I never would have figured that out.
Thank you very much for your help!
"Kasper Dupont" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Soren wrote:
> >
> > Greetings,
> >
> > I am trying to write a *very* simple character device driver (straight
out
> > of a book) and am getting an error that I cannot fix and do not
> > understand. Any help is appreciated.
> >
> > The pertinent details:
> > Mandrake 7.2 (kernel 2.2.17)
> >
> > in the driver:
> >
> > static char * Message_Ptr;
> > static char Message_buf[100];
> >
> > static ssize_t device_read ( struct file * file, char * buffer, size_t
> > length, loff_t * offset )
> > {
> > <snip>
> > while ( length && * Message_Ptr )
> > {
> > put_user( *(Message_Ptr), buffer);
> > Message_Ptr++;
> > buffer++;
> > length--;
> > }
> >
> >
> > the problem is that the module won't load with a report of :
> > unresolved symbol __put_user_X
> >
> > which implies that the size of the target (ptr) is neither 1, 2, nor 4
> > bytes (!?) However, using copy_to_user works very well.
> >
> > what am I missing?
> > If I try to force it (via hacking the macro) to use put_user_1 it
returns
> > garbage. Help?
> >
>
> This means that either the type has incorrect size
> (not 1, 2, or 4), or you forgot to compile with
> optimization. Did you specify -O2 on the command
> line when compiling?
>
> --
> Kasper Dupont
------------------------------
From: "tlin" <[EMAIL PROTECTED]>
Subject: How to call a function and don't wait for return
Date: Wed, 28 Mar 2001 11:12:45 -0700
hi,
I want to initialize some functions when I load my module into the kernel.
These functions need to share some common data within this module,
and basically, they will never end until the module is terminated.
I don't know whether it is possible? If yes, then how to implement it?
Thanks a lot!
- tao
------------------------------
From: [EMAIL PROTECTED] (Phil Ehrens)
Subject: Re: C++ and shell
Date: 28 Mar 2001 17:06:54 GMT
Reply-To: -@-
While Giovanni is preparing his example, you may want to look at:
http://www.ibiblio.org/pub/gnu/Manuals/glibc-2.0.6/html_node/libc_176.html
Giovanni Meneghetti wrote:
>You have to dup the stdout to a file descriptor, the fork, then exec.
>If you need an example, I may send you one of my old works.
>
>Bye
>Giovanni Meneghetti
>
>FLD wrote:
>
>> I'm making a GUI for a command line tool i often use. til now i've used
>> the "system" command which works fine, but i'm now interested in getting
>> the tool output (text) in my program. How can i make it work ?
------------------------------
From: Markus Kossmann <[EMAIL PROTECTED]>
Subject: Re: uart
Date: Wed, 28 Mar 2001 18:41:03 +0200
Josef Allen wrote:
>
> Does anyone Know how to directly program the uart using inb() and outb
> functions.
>
Did you allready read the IO-Port-Programming mini-Howto ?
--
Markus Kossmann
[EMAIL PROTECTED]
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: How to call a function and don't wait for return
Date: Wed, 28 Mar 2001 17:49:09 -0000
On Wed, 28 Mar 2001 11:12:45 -0700 tlin <[EMAIL PROTECTED]> wrote:
| I want to initialize some functions when I load my module into the kernel.
| These functions need to share some common data within this module,
| and basically, they will never end until the module is terminated.
|
| I don't know whether it is possible? If yes, then how to implement it?
| Thanks a lot!
If you are coding in assembly, you might be able to just branch
directly to the other function. Make sure your stack integrity
is correct.
If you are coding in C, there's no real way to do this cleanly.
If the code calling the module can stay resident, don't worry
about it. If it's big and you need to get it out of there, then
maybe you can reorganize so that something else calls the function
to initialize, then calls the module, so that the initializer is
all done. If you have flexibility in the design, maybe you can
pass an optional initializer function pointer to the module and
have it call that function if not NULL.
I'd love it if C had an easy way to do what you want to do. But
since it doesn't, you'll just have to work around it like I have.
--
=================================================================
| Phil Howard - KA9WGN | Dallas | http://linuxhomepage.com/ |
| [EMAIL PROTECTED] | Texas, USA | http://phil.ipal.org/ |
=================================================================
------------------------------
From: "Astroboy" <[EMAIL PROTECTED]>
Crossposted-To: alt.os.linux,comp.os.linux.embedded,linux.dev.kernel
Subject: compile kernel error
Date: Thu, 29 Mar 2001 03:14:33 +0800
when i compile the kernel, i got this error message:
/usr/src/linux/include/linux/modules/i386_ksyms.ver:142:1: warning: this is
the location of the previous definition
make[2]: *** [ksyms.o] Error 1
make[2]: Leaving directory `/usr/src/linux-2.2.16/kernel'
make[1]: *** [first_rule] Error 2
make[1]: Leaving directory `/usr/src/linux-2.2.16/kernel'
make: *** [_dir_kernel] Error 2
[root@localhost linux]#
Please help.
Eric
------------------------------
From: Josef Allen <[EMAIL PROTECTED]>
Subject: Realtime programming
Date: Wed, 28 Mar 2001 14:58:31 -0500
Hey,
I am a grad student and I am looking to do some programming in robotics.
I would like to know if there are some development kits for such a thing
and if so where. I am open to any suggestions
Josef D. Allen
------------------------------
From: Josef Allen <[EMAIL PROTECTED]>
Subject: Re: uart
Date: Wed, 28 Mar 2001 14:59:51 -0500
Where is this web page at
Josef D. Allen
On Wed, 28 Mar 2001, Markus Kossmann wrote:
> Josef Allen wrote:
> >
> > Does anyone Know how to directly program the uart using inb() and outb
> > functions.
> >
> Did you allready read the IO-Port-Programming mini-Howto ?
>
> --
> Markus Kossmann
> [EMAIL PROTECTED]
>
>
------------------------------
From: [EMAIL PROTECTED]
Subject: interaction userspace with kernel
Date: Wed, 28 Mar 2001 20:23:08 GMT
lets say userspace does this:
getsockopt(sockfd, IPPROTO_IP, EPF_SO_GET_INFO, &info, &length)
in the code I have seen the kernel will use
copy_from_user(destination, info, size) to get the info in kernel
memory. But to get the length, the kernel just uses *length.
Why doesn't the kernel have to do copy_from_user(destination2, length,
sizeof(int)) ?
------------------------------
From: Kasper Dupont <[EMAIL PROTECTED]>
Crossposted-To: alt.os.linux,comp.os.linux.embedded,linux.dev.kernel
Subject: Re: compile kernel error
Date: Wed, 28 Mar 2001 20:27:49 +0000
Astroboy wrote:
>
> when i compile the kernel, i got this error message:
>
> /usr/src/linux/include/linux/modules/i386_ksyms.ver:142:1: warning: this is
> the location of the previous definition
> make[2]: *** [ksyms.o] Error 1
> make[2]: Leaving directory `/usr/src/linux-2.2.16/kernel'
> make[1]: *** [first_rule] Error 2
> make[1]: Leaving directory `/usr/src/linux-2.2.16/kernel'
> make: *** [_dir_kernel] Error 2
> [root@localhost linux]#
>
> Please help.
>
> Eric
This problem is very often seen on RedHat 7.0.
RedHat 7.0 is a mess when it comes to kernel
compilation. It is shipped with two different
gcc versions, one set of kernel sources for
install, another set which is used to build
the kernel installed on the system, and header
files from a third kernel. The kernel sources
installed comes with a lot of patches some of
which are broken.
Compiling without symbol version numbers solves
most of the problems. After changing this
option you will have to manually delete all .ver
files and a single header file which includes
all the .ver files.
For some obscure reason symbol version numbers
is not a problem when compiling an SMP kernel.
A few other hints which might help you:
Touch the makefile in the top directory, this
will force remaking a file which has a broken
patch.
You might need to remove the -traditional
option in a Makefile in one directory containing
some assembler sources.
Also consider downloading kernel sources without
RedHat patches.
Some problems can be solved if /usr/src/linux,
/usr/src/linux-whatever, /usr/include/asm, and
/usr/include/linux are actually from the same
version.
Even if you have followed all of theese hints,
there are still lot of potential problems:
You will still have a mixture of different gcc
versions, and you might have glibc compiled for
some completely different kernel version.
On RedHat 6.0 I have not experienced a single
of theese problems. Another approach when
installing a system would be to install RedHat
6.0 and upgrade all packages where you need,
something newer. I think most of the SRPMS from
RedHat 7.0 can be installed and build on a 6.0
system, if you first install a rpm version 4
statically linked binary somewhere, e.g.
/bin/rpm4.
I have never tried other distributions, but I
wouldn't believe that there exist any other
distribution with the same mess as RedHat 7.0.
Hopefully RedHat 7.1 comes with *ONE* kernel
version, *ONE* gcc version, and *ONE* glibc
version that are actually compatible.
--
Kasper Dupont
------------------------------
From: "Osiris Pedroso" <[EMAIL PROTECTED]>
Subject: Re: can any one suggest the editor for linux,other than vi, which is similar
to Editor for Windows.....
Date: Wed, 28 Mar 2001 20:54:47 GMT
I have used Visual Slick Edit for Linux.
It is great.
The Code Browsing capabilities are very nice and the Diff capabilities are
also great.
Check it out.
Osiris
""v.nagasrinivas"" <[EMAIL PROTECTED]> wrote in message
news:001601c0b11d$0efbe110$0900a8c0@srinivas...
Hi ,
Can any body suggest the editor for linux, which is similar to
Editor for windows..(www.gensoft.com).
Because through the code reading ( means searching through several files at
a time and other things are very easy..)
thanks in advance,
srinivas.
v.naga srinivas
YVL Software Consultancy
B4,Q1,6th floor,Hi-Tec city,
CyberTowers, Madhapur,
Hyderabad - 500033
Andhra Pradesh
INDIA
phone : 091-040-3110200(off)
091-040-3810616(res)
visit me: www.geocities.com/cheluvi
------------------------------
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