Re: 2.6.8-rc4-bk1 problem: unregister_netdevice: waiting for ppp0

[Patrick McHardy <kaber@xxxxxxxxx>]

Voluspa wrote:

> Greetings,
>
> NOTE
> I wrote the text below just prior to the posting of
> 01-2.6-cbq-leaks.diff but applying it doesn't change the
> situation here. I still get the same Oops as below. Slight
> changes in memory address but the Call Trace is identical.
> So, different problem?
> ENDNOTE
>  

Did you also apply this patch ? If not, please try it and tell us
if it helps.

Regards
Patrick

> Yes, saw the same thing on eth0 but had a confusing time to catch a
> clean error situation. Having been used to stable kernels for a long
> time I've disabled all debugging options and compile for size. So
> when 2.6.8[.1] threw an Oops at the end of every "shutdown -r now"
> the feedback was useless ("halt" gave no Oops). What looked to be
> the same Oops came when doing a "rmmod 8139too". 2.6.7 has no such
> issues.
>
> Turning on CONFIG_KALLSYMS (and CONFIG_CC_OPTIMIZE_FOR_SIZE off), with
> CONFIG_FRAME_POINTER, a slew of other debug options and the
> CONFIG_MAGIC_SYSRQ, hid the Oops and gave the result Nuno Silva
> has described.
>
> To make a long story short, I didn't trust my very old system enough
> to report.
>
> But now I've seen the QoS/wshaper connection and achieved a good Oops
> with only CONFIG_KALLSYMS and CONFIG_FRAME_POINTER set.
>
> Typing it here in case it has some kind of value (hand-copied):
>
> [...]
> Unmounting local filesystems...
> Flushing filesystem buffers...
> Please stand by while rebooting...
> Unable to handle kernel paging request at virtual address 8bc289a9
> printing eip:
> c02ae9c0
> *pde = 00000000
> Ooops: 0000 [#1]
> PREEMPT
> Modules linked in: 8139too crc32
> CPU:    0
> EIP:    0060:[<c02ae9c0>]   Not tainted
> EFLAGS: 00010286   (2.6.8-debug)
> EIP is at fib_sync_down+0x50/0xb0
> eax: cfaee800 ebx: 948bff0d ecx: 8bc28955 edx: c0267eb8
> esi: 00000001 edi: 00000000 ebp: cf0a1ea4 esp: cf0a1e8c
> de: 007b es: 007b ss: 0068
> Process reboot (pid: 151, threadinfo=cf0a1000 task=cfa3e090)
> Stack:
> 000000ff 00000001 cfaee800 cfaee800 cfaee800 00000002 cf0a1eb0 c02ad8d1
> c033affc cf0a1ebc c02ad9b9 c033affc cf0a1ed0 c0121508 cfaee800 00000002
> 00001003 cf0a1ee0 c025dadf cfaee800 00000002 cf0a1ef8 c025ef32 00000000
> Call Trace:
> [<c0104d7a>] show_stack+0x7a/0x90
> [<c0104ef9>] show_registers+0x149/0x1a0
> [<c010508d>] die+0x8d/0x100
> [<c0111b45>] do_page_fault+0x1e5/0x569
> [<c0104a15>] error_code+0x2d/0x38
> [<c02ad8d1>] fib_disable_ip+0x11/0x30
> [<c02ad9b9>] fib_netdev_event+0x69/0x80
> [<c0121508>] notifier_call_chain+0x28/0x50
> [<c025dadf>] dev_close+0x8f/0xa0
> [<c025ef32>] dev_change_flags+0x52/0x120
> [<c02a82f5>] devinet_ioctl+0x245/0x590
> [<c02aa573>] inet_ioctl+0x63/0xb0
> [<c0255b82>] sock_ioctl+0xe2/0x230
> [<c0159a95>] sys_ioctl+0x105/0x260
> [<c010400b>] syscall_call+0x7/0xb
> Code: 8b 41 54 85 c0 74 19 8d 51 58 31 f6 8b 5a 04 f6 c3 01 74 2c
> /etc/rc.d/rc.6: line 49: 151 Segmentation fault /sbin/reboot -d -f -i
> INIT: no more processes left in this runlevel
> <5>portmap: server localhost not responding, timed out
> RPC: failed to contact portmap (errno -5).
> portmap: server localhost not responding, timed out
> RPC: failed to contact portmap (errno -5).
> --endOops--
>
> The -i parametre to reboot (which is a symlink to halt) means to shut
> down all network interfaces. My halt command doesn't use the -i, hence
> the lack of Oops.
>
> Mvh
> Mats Johannesson
>
>
>
>  

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2004/08/15 19:33:16-07:00 kaber@xxxxxxxxx 
#   [PKT_SCHED]: cacheline-align qdisc data in qdisc_create()
#   
#   Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
#   Signed-off-by: David S. Miller <davem@xxxxxxxxxx>
# 
# net/sched/sch_api.c
#   2004/08/15 19:32:59-07:00 kaber@xxxxxxxxx +13 -8
#   [PKT_SCHED]: cacheline-align qdisc data in qdisc_create()
#   
#   Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
#   Signed-off-by: David S. Miller <davem@xxxxxxxxxx>
# 
diff -Nru a/net/sched/sch_api.c b/net/sched/sch_api.c
--- a/net/sched/sch_api.c       2004-08-23 19:06:53 +02:00
+++ b/net/sched/sch_api.c       2004-08-23 19:06:53 +02:00
@@ -389,7 +389,8 @@
 {
        int err;
        struct rtattr *kind = tca[TCA_KIND-1];
-       struct Qdisc *sch = NULL;
+       void *p = NULL;
+       struct Qdisc *sch;
        struct Qdisc_ops *ops;
        int size;
 
@@ -407,12 +408,18 @@
        if (ops == NULL)
                goto err_out;
 
-       size = sizeof(*sch) + ops->priv_size;
+       /* ensure that the Qdisc and the private data are 32-byte aligned */
+       size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
+       size += ops->priv_size + QDISC_ALIGN_CONST;
 
-       sch = kmalloc(size, GFP_KERNEL);
+       p = kmalloc(size, GFP_KERNEL);
        err = -ENOBUFS;
-       if (!sch)
+       if (!p)
                goto err_out;
+       memset(p, 0, size);
+       sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST)
+                              & ~QDISC_ALIGN_CONST);
+       sch->padded = (char *)sch - (char *)p;
 
        /* Grrr... Resolve race condition with module unload */
 
@@ -420,8 +427,6 @@
        if (ops != qdisc_lookup_ops(kind))
                goto err_out;
 
-       memset(sch, 0, size);
-
        INIT_LIST_HEAD(&sch->list);
        skb_queue_head_init(&sch->q);
 
@@ -470,8 +475,8 @@
 
 err_out:
        *errp = err;
-       if (sch)
-               kfree(sch);
+       if (p)
+               kfree(p);
        return NULL;
 }