[uml-user] UML exits in init_lines?

[Bart S. <bs...@li...>]

Hi guys,

Here's my trouble. I hope someone here can help me out. I'm trying to 
get UML to run on Debian (sid), and when I run it, it exits 
mysteriously. This is the output I get:

-----------------------------------Cut------------------------------------------
tracing thread pid = 6335
Linux version 2.4.19-1um (root@zappa) (gcc version 2.95.4 20011002 
(Debian prerelease)) #15 Tue Aug 27 10:52:44 CEST 2002
On node 0 totalpages: 8192
zone(0): 8192 pages.
zone(1): 0 pages.
zone(2): 0 pages.
Kernel command line: root=/dev/ubd0
Calibrating delay loop... 1976.73 BogoMIPS
Memory: 30568k available
Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
Checking for host processor cmov support...Yes
Checking for host processor xmm support...No
Checking that ptrace can change system call numbers...OK
Checking that host ptys support output SIGIO...No, enabling workaround
Checking that host ptys support SIGIO on close...No, enabling workaround
POSIX conformance testing by UNIFIX
Linux NET4.0 for Linux 2.4
Based upon Swansea University Computer Society NET3.039
Initializing RT netlink socket
Starting kswapd
Installing knfsd (copyright (C) 1996 ok...@mo...).
pty: 256 Unix98 ptys configured
SCSI subsystem driver Revision: 1.00
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
IP: routing cache hash table of 512 buckets, 4Kbytes
TCP: Hash tables configured (established 2048 bind 2048)
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
Initializing stdio console driver
before INIT_LIST_HEAD; lines = a0186720, nlines = 8
---------------------------------Cut--------------------------------

Then it TERMINATES without any error message. I've added some printks in 
the thing to find out what happens, and it turns out that the exit 
happens here (from arch/um/drivers/line.c):

void lines_init(struct line *lines, int nlines)
{
	int i;
	for(i = 0; i < nlines; i++){
		printk("before INIT_LIST_HEAD; lines = %p, nlines = %d\n", lines, nlines);
		INIT_LIST_HEAD(&lines[i].chan_list);
		printk("past INIT_LIST_HEAD\n");
		sema_init(&lines[i].sem, 1);
	}
}


So, it exits on the INIT_LIST_HEAD. When I try to access 
lines[i].chan_list.next manually , I get an "I'm tracing myself and I 
can't get out" message.

Some configuration details:
* Using kernel-source-2.4.19 package from the Debian sid archive.
* Applied the uml patch 2.4.19-1.
* Using the default kernel configuration (I ran make xconfig ARCH=uml 
after deleting .config).
* Compiling with gcc-2.95.4 (Debian-specific gcc version extracted from 
gcc CVS - this shouldn't be a problem.)

Has anybody seen anything like this before? Any help is very much 
appreciated!

Regards,
Bart Samwel

-- 

Leiden Institute of Advanced Computer Science (LIACS)
E-mail: bs...@li...    Telephone: +31-71-5277037
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