hello LKML
I am testing a customized TCP/IP offloaded stack code. Its working fine with basic data transmission in between two peers. After 6-7 packet transmission it suddnely give me null pointer dereference bug. The null pointer bug comes at unix datagram sockets. I don't understand the interaction of TCP/IP sock object with the unix datagram socket. the bug details has been attached 1. this is the first bug <1>[ 637.540746] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000004 <1>[ 637.549320] printing eip: <4>[ 637.552047] c126cd6e <1>[ 637.552049] *pde = 00000000 <0>[ 637.554869] Oops: 0002 [#1] <0>[ 637.557687] SMP DEBUG_PAGEALLOC <4>[ 637.560972] Modules linked in: dcxgb3 upcxgb3 locxgb3 uhci_hcd intel_agp agpgart <0>[ 637.568675] CPU: 0 <4>[ 637.568676] EIP: 0060:[<c126cd6e>] Not tainted VLI <4>[ 637.568677] EFLAGS: 00010006 (2.6.18-debug #3) <0>[ 637.581026] EIP is at skb_dequeue+0x2e/0x60 <0>[ 637.585228] eax: 00000000 ebx: f7b1c734 ecx: c1fcf530 edx: 00000286 [0]more> <0>[ 637.592042] esi: f595dd80 edi: f7b1c740 ebp: f6791d1c esp: f6791d10 <0>[ 637.598849] ds: 007b es: 007b ss: 0068 <0>[ 637.602974] Process syslogd (pid: 3710, ti=f6790000 task=c1fcf530 task.ti=f6790000) <0>[ 637.610479] Stack: 000003fe f7b1c680 f6791dbc f6791d54 c127033c f7b1c734 f7b1c734 7fffffff <0>[ 637.619233] 00000000 f7b1c8ac f6791f20 f6791dbc f6791d54 c12e9199 000003fe f6791f20 <0>[ 637.627990] f6791dbc f6791da0 c12ca1ab f7b1c680 00000000 00000000 f6791d90 00000001 <0>[ 637.636745] Call Trace: <4>[ 637.639447] [<c1004831>] show_stack_log_lvl+0xb1/0xe0 <4>[ 637.644655] [<c1004a65>] show_registers+0x1b5/0x240 <4>[ 637.649682] [<c1004c2e>] die+0x13e/0x390 <4>[ 637.653755] [<c12ec0bc>] do_page_fault+0x32c/0x670 <4>[ 637.658698] [<c1004341>] error_code+0x39/0x40 <4>[ 637.663205] [<c127033c>] skb_recv_datagram+0x13c/0x210 <4>[ 637.668490] [<c12ca1ab>] unix_dgram_recvmsg+0x7b/0x240 <4>[ 637.673777] [<c1267485>] sock_recvmsg+0xe5/0x110 <4>[ 637.678543] [<c1268e97>] sys_recvfrom+0x97/0x100 <4>[ 637.683311] [<c1268f36>] sys_recv+0x36/0x40 <4>[ 637.687645] [<c1269373>] sys_socketcall+0x163/0x260 <4>[ 637.692673] [<c1003793>] syscall_call+0x7/0xb <0>[ 637.697180] Code: 83 ec 0c 89 1c 24 8b 5d 08 89 7c 24 08 89 74 24 04 8d 7b 0c 89 f8 e8 b2 dd 07 00 8b 33 39 f3 89 c2 7 <0>[ 637.718832] EIP: [<c126cd6e>] skb_dequeue+0x2e/0x60 SS:ESP 0068:f6791d10 <4>[ 637.725643] [0]kdb> dcxgb3: driver code upcxgb3 and locxgb3: TCP/IP stack code. 2. the second bug after a delay of 10-15 second a softlock up bug raises. <0>[ 637.718832] EIP: [<c126cd6e>] skb_dequeue+0x2e/0x60 SS:ESP 0068:f6791d10 <4>[ 637.725643] <0>BUG: spinlock lockup on CPU#1, klogd/3746, f7b1c740 <4>[ 899.151233] [<c10048ab>] show_trace+0x1b/0x20 <4>[ 899.155936] [<c1004ff6>] dump_stack+0x26/0x30 <4>[ 899.160643] [<c114b160>] _raw_spin_lock+0x110/0x150 <4>[ 899.165872] [<c12eab60>] _spin_lock_irqsave+0x50/0x60 <4>[ 899.171289] [<c126cc51>] skb_queue_tail+0x21/0x50 <4>[ 899.176357] [<c12c8f5c>] unix_dgram_sendmsg+0x42c/0x510 <4>[ 899.181938] [<c1267074>] do_sock_write+0xb4/0xc0 <4>[ 899.186920] [<c1267807>] sock_aio_write+0x67/0x70 <4>[ 899.191974] [<c1067ea9>] do_sync_write+0xb9/0xf0 <4>[ 899.196936] [<c10689c0>] vfs_write+0x190/0x1a0 <4>[ 899.201731] [<c1069107>] sys_write+0x47/0x70 <4>[ 899.206367] [<c1003793>] syscall_call+0x7/0xb and i am sure these two bugs are inter-related.. System Details: Linux helvella 2.6.18-debug #3 SMP Fri Aug 10 14:08:20 IST 2007 i686 GNU/Linux any suggestion why this interaction is happening. or what i am doing wrong? thank you - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
