Hi, Thanks for your answer. But sorry I'm not capable to debug this problem. I noticed this problem occurs only if nobody heards the multicast group when the message was send. Perhaps, I didn't use the correct flags when I create or send the msg (in functions genlmsg_put or genlmsg_multicast). I didn't find a good doc on its flags. Doude. On Nov 21, 2007 6:27 PM, Breno Leitao <leitao@xxxxxxxxxxxxxxxxxx> wrote: > Hello Edouard, > > I've tried your example using the HEAD kernel (2.6.23.8) on a ppc > machine. > As you said, it is crashing the operating system, and as I am using > xmon, it shows the backtrace and the register states during the failure. > IMHO there is something wrong with the message, which could be > dereferencing the genl header, causing the following message "Unable to > handle kernel paging request for data at address 0x00000008" > I hope this helps. > > ... > error on genlmsg_multicast -3 > Failure > Unable to handle kernel paging request for data at address 0x00000008 > Faulting instruction address: 0xc0000000002ebe0c > cpu 0x1: Vector: 300 (Data Access) at [c000000053f53500] > pc: c0000000002ebe0c: .skb_dequeue+0x5c/0x94 > lr: c0000000002ebdd8: .skb_dequeue+0x28/0x94 > sp: c000000053f53780 > msr: 8000000000009032 > dar: 8 > dsisr: 42000000 > current = 0xc000000053a72570 > paca = 0xc00000000050d480 > pid = 1643, comm = syslogd > enter ? for help > [c000000053f53810] c0000000002efc3c .skb_recv_datagram+0xe8/0x2b8 > [c000000053f538f0] c00000000037d8d4 .unix_dgram_recvmsg+0x84/0x348 > [c000000053f539f0] c0000000002e443c .sock_recvmsg+0x114/0x160 > [c000000053f53c00] c0000000002e5c1c .sys_recvfrom+0xec/0x170 > [c000000053f53d90] c000000000309934 .compat_sys_socketcall+0x178/0x214 > [c000000053f53e30] c000000000008534 syscall_exit+0x0/0x40 > --- Exception: c01 (System Call) at 000000001ff500d0 > SP (fff4f600) is in userspace > 1:mon> t > [c000000053f53810] c0000000002efc3c .skb_recv_datagram+0xe8/0x2b8 > [c000000053f538f0] c00000000037d8d4 .unix_dgram_recvmsg+0x84/0x348 > [c000000053f539f0] c0000000002e443c .sock_recvmsg+0x114/0x160 > [c000000053f53c00] c0000000002e5c1c .sys_recvfrom+0xec/0x170 > [c000000053f53d90] c000000000309934 .compat_sys_socketcall+0x178/0x214 > [c000000053f53e30] c000000000008534 syscall_exit+0x0/0x40 > --- Exception: c01 (System Call) at 000000001ff500d0 > SP (fff4f600) is in userspace > 1:mon> r > R00 = 0000000000000000 R16 = 0000000020008ac8 > R01 = c000000053f53780 R17 = 0000000020008ac0 > R02 = c0000000005e3a60 R18 = 0000000020008aa8 > R03 = 0000000000000001 R19 = 0000000020008a80 > R04 = 0000000000000001 R20 = 0000000020008a7c > R05 = 0000000000000000 R21 = 0000000020019dfc > R06 = c000000053f53960 R22 = 0000000020019a84 > R07 = 0000000000000000 R23 = c000000002df8880 > R08 = 0000000000000000 R24 = 0000000000000000 > R09 = 0000000000000000 R25 = c000000053f53960 > R10 = c0000000481e3508 R26 = 7fffffffffffffff > R11 = 0000000000000000 R27 = c000000053f53c88 > R12 = 000003fe00000000 R28 = c00000005aa15c44 > R13 = c00000000050d480 R29 = c00000005aa15c30 > R14 = 0000000020008b1c R30 = c0000000005aabf8 > R15 = 0000000020008ae0 R31 = c000000051fbe280 > pc = c0000000002ebe0c .skb_dequeue+0x5c/0x94 > lr = c0000000002ebdd8 .skb_dequeue+0x28/0x94 > msr = 8000000000009032 cr = 24000488 > ctr = c00000000037d850 xer = 0000000020000009 trap = 300 > dar = 0000000000000008 dsisr = 42000000 > > Regards, > Breno > --- > Breno Leitão > +55 (16) 8115-3915 > IBM Linux Technology Center > > > On Mon, 2007-11-12 at 17:47 +0100, Edouard Thuleau wrote: > > Hi, > > > > I try to use the generic netlink functionalities in a kernel module. > > > > I looked the doc > > http://www.linux-foundation.org/en/Net:Generic_Netlink_HOWTO and the > > source code of kernel/taskstats.c in the kernel. > > I tried to reproduce the example of the doc (look in the attached > > file) but it doesn't work. > > > > I work on a 2.6.23 kernel and on two different architectures, a > > classic x86 pc and a armv5b board. > > On the PC the genlmsg_multicast function return an error (-3) and the > > system crash totally in the next 5 sec (hard reboot). > > On the arm board, the genlmsg_put function return the NULL value, but > > the module is unload and the system stay stable. > > > > Can you help me ? > > Doude. > > - > > To unsubscribe from this list: send the line "unsubscribe linux-net" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > - > To unsubscribe from this list: send the line "unsubscribe linux-net" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
