[Crash-utility] [PATCH] crash: add dev_base_head support for net command

[Dave Anderson]

Eugene Teo wrote:
> Hi Dave,
> 
> I found that the net command in crash 4.0-6.1 does not work with Fedora
> kernel 2.6.23.14-115.fc8. There was a rework on dev_base[1] to replace
> the use of dev_base variable, and dev->next pointer with for_each_netdev
> loop. This patch fixes this problem.
> 

Thanks Eugene -- queued for the next release.

BTW, the patch looks to have a short shelf-life.  In 2.6.24, the
new dev_base_head list_head that your patch looks for no longer
exists.  So for now I've also updated the error message in
show_net_devices() to complain if both dev_base and dev_base_head
don't exist.

I'll update the TODO list with the newer net command issue
if anybody wants to take a shot at fixing it.

Thanks,
   Dave


> $ uname -rm
> 2.6.23.14-115.fc8 i686
> $ sudo ./crash
> [...]
> crash> net
> net: dev_base does not exist!
> 
> With the patch,
> 
> $ sudo ./crash
> [...]
> crash> net
> NET_DEVICE  NAME   IP ADDRESS(ES)
>  c0714480   lo     127.0.0.1
>  f7031000   wmaster0 
>  f7031800   wlan0  
>  f775c000   eth0   a.b.c.d
>  f6d3a000   redhat0 w.x.y.z
> 
> [1] linux-2.6 commit: 7562f876cd93800f2f8c89445f2a563590b24e09
>     [NET]: Rework dev_base via list_head (v3)
> 
> Signed-off-by: Eugene Teo <eugeneteo at kernel.sg>
> 
> diff -uprN crash-4.0-6.1.default/defs.h crash-4.0-6.1/defs.h
> --- crash-4.0-6.1.default/defs.h	2008-02-29 00:09:10.000000000 +0800
> +++ crash-4.0-6.1/defs.h	2008-03-16 13:51:32.000000000 +0800
> @@ -1234,6 +1234,7 @@ struct offset_table {                   
>  	long net_device_type;
>  	long net_device_addr_len;
>  	long net_device_ip_ptr;
> +	long net_device_dev_list;
>  	long device_next;
>  	long device_name;
>  	long device_type;
> diff -uprN crash-4.0-6.1.default/net.c crash-4.0-6.1/net.c
> --- crash-4.0-6.1.default/net.c	2008-02-29 00:09:10.000000000 +0800
> +++ crash-4.0-6.1/net.c	2008-03-16 14:01:39.000000000 +0800
> @@ -65,6 +65,7 @@ struct devinfo {
>  #define BYTES_IP_TUPLE	(BYTES_IP_ADDR + BYTES_PORT_NUM + 1)
>  
>  static void show_net_devices(void);
> +static void show_net_devices_v2(void);
>  static void print_neighbour_q(ulong, int);
>  static void get_netdev_info(ulong, struct devinfo *);
>  static void get_device_name(ulong, char *);
> @@ -111,6 +112,7 @@ net_init(void)
>  			"net_device", "addr_len");
>  		net->dev_ip_ptr = MEMBER_OFFSET_INIT(net_device_ip_ptr,
>  			"net_device", "ip_ptr");
> +		MEMBER_OFFSET_INIT(net_device_dev_list, "net_device", "dev_list");
>  		ARRAY_LENGTH_INIT(net->net_device_name_index,
>  			net_device_name, "net_device.name", NULL, sizeof(char));
>  		net->flags |= (NETDEV_INIT|STRUCT_NET_DEVICE);
> @@ -355,6 +357,11 @@ show_net_devices(void)
>  	long flen;
>  	char buf[BUFSIZE];
>  
> +	if (symbol_exists("dev_base_head")) {
> +		show_net_devices_v2();
> +		return;
> +	}
> +
>  	if (!symbol_exists("dev_base"))
>  		error(FATAL, "dev_base does not exist!\n");
>  
> @@ -384,6 +391,58 @@ show_net_devices(void)
>  	} while (next);
>  }
>  
> +static void
> +show_net_devices_v2(void)
> +{
> +	struct list_data list_data, *ld;
> +	char *net_device_buf;
> +	char buf[BUFSIZE];
> +	ulong *ndevlist;
> +	int ndevcnt, i;
> +	long flen;
> +
> +	if (!net->netdevice) /* initialized in net_init() */
> +		return;
> +
> +	flen = MAX(VADDR_PRLEN, strlen(net->netdevice));
> +
> +	fprintf(fp, "%s  NAME   IP ADDRESS(ES)\n",
> +		mkstring(upper_case(net->netdevice, buf), 
> +			flen, CENTER|LJUST, NULL));
> +
> +	net_device_buf = GETBUF(SIZE(net_device));
> +
> +	ld =  &list_data;
> +	BZERO(ld, sizeof(struct list_data));
> +	get_symbol_data("dev_base_head", sizeof(void *), &ld->start);
> +	ld->end = symbol_value("dev_base_head");
> +	ld->list_head_offset = OFFSET(net_device_dev_list);
> +
> +	hq_open();
> +	ndevcnt = do_list(ld);
> +	ndevlist = (ulong *)GETBUF(ndevcnt * sizeof(ulong));
> +	ndevcnt = retrieve_list(ndevlist, ndevcnt);
> +	hq_close();
> +
> +	for (i = 0; i < ndevcnt; ++i) {
> +		readmem(ndevlist[i], KVADDR, net_device_buf,
> +			SIZE(net_device), "net_device buffer",
> +			FAULT_ON_ERROR);
> +
> +                fprintf(fp, "%s  ",
> +			mkstring(buf, flen, CENTER|RJUST|LONG_HEX,
> +			MKSTR(ndevlist[i])));
> +
> +		get_device_name(ndevlist[i], buf);
> +		fprintf(fp, "%-6s ", buf);
> +
> +		get_device_address(ndevlist[i], buf);
> +		fprintf(fp, "%s\n", buf);
> +	}
> +	
> +	FREEBUF(ndevlist);
> +	FREEBUF(net_device_buf);
> +}
>  
>  /*
>   * Perform the actual work of dumping the ARP table...
> 
> --
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