Messages in this thread | | | Date | Thu, 22 Jul 2004 18:53:20 +0100 | From | Cam <> | Subject | linux-2.4.20_mvl31 OOPS ip_route_input called within ip_rt_init |
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Hi,
I have an embedded ppc linux which sometimes can oops at boot time if it receives a packet during ip_rt_init. There is a printk in there in the middle of initialisation of rt_hash_table which can introduce a delay which makes the problem more likely to happen,
Output before the oops: NET4: Linux TCP/IP 1.0 for NET4.0 IP Protocols: ICMP, UDP, TCP, IGMP IP: routing cache hash table of 4096 buckets, 32Kbytes <4>Oops: kernel access of bad area, sig: 11
Decoded trace (my arrows):
Trace; c00ffcfc <ip_route_input+40/21c> <-- Trace; c010339c <ip_rcv_finish+24c/258> Trace; c00f0af8 <netif_receive_skb+118/224> Trace; c00f0ca0 <process_backlog+9c/178> Trace; c00f0e14 <net_rx_action+98/18c> Trace; c001cfec <do_softirq+134/138> Trace; c000723c <do_IRQ+c4/c8> Trace; c00072c0 <preempt_intercept+80/84> Trace; c0005ecc <ret_from_intercept+0/8c> Trace; c0068d9c <proc_register+1c/f4> Trace; c00173a8 <call_console_drivers+c0/160> Trace; c00177cc <release_console_sem+84/130> Trace; c0017630 <printk+170/1f0> Trace; c0198294 <ip_rt_init+128/2c8> <-- Trace; c0198530 <ip_init+1c/5c> Trace; c0198d74 <inet_init+f0/220> Trace; c01896b0 <do_initcalls+30/50> Trace; c0003b40 <init+28/200> Trace; c000894c <arch_kernel_thread+30/3c>
Code:
int ip_route_input(struct sk_buff *skb, u32 daddr, u32 saddr, u8 tos, struct net_device *dev) { struct rtable * rth; unsigned hash; int iif = dev->ifindex;
tos &= IPTOS_RT_MASK; hash = rt_hash_code(daddr, saddr ^ (iif << 5), tos);
read_lock(&rt_hash_table[hash].lock); <-- oops here!!
[...]
void __init ip_rt_init(void) {
[...]
rt_hash_table = (struct rt_hash_bucket *) __get_free_pages(GFP_ATOMIC, order); } while (rt_hash_table == NULL && --order > 0);
if (!rt_hash_table) panic("Failed to allocate IP route cache hash table\n");
printk(KERN_INFO "IP: routing cache hash table of %u buckets, %ldKbytes\n", rt_hash_mask, (long) (rt_hash_mask * sizeof(struct rt_hash_bucket)) / 1024);
for (rt_hash_log = 0; (1 << rt_hash_log) != rt_hash_mask; rt_hash_log++) /* NOTHING */;
rt_hash_mask--; for (i = 0; i <= rt_hash_mask; i++) { rt_hash_table[i].lock = RW_LOCK_UNLOCKED; rt_hash_table[i].chain = NULL; }
Is this a known problem?
What can be done to prevent this? Should the device be held inactive somehow until ip_rt_init has completed? Should I just move the printk to later in the code and hope for the best?
Any info gratefully received,
-Cam -- camilo@mesias.co.uk <-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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