Hi, Maran reported the bug below (vanilla 2.6.30-rc8): BUG: sleeping function called from invalid context at /mnt/s390test/linux-2.6-tip/arch/s390/include/asm/uaccess.h:234 in_atomic(): 1, irqs_disabled(): 0, pid: 3245, name: sysctl CPU: 1 Not tainted 2.6.30-rc8-tipjun10-02053-g39ae214 #1 Process sysctl (pid: 3245, task: 000000007f675da0, ksp: 000000007eb17cf0) 0000000000000000 000000007eb17be8 0000000000000002 0000000000000000 000000007eb17c88 000000007eb17c00 000000007eb17c00 0000000000048156 00000000003e2de8 000000007f676118 000000007eb17f10 0000000000000000 0000000000000000 000000007eb17be8 000000000000000d 000000007eb17c58 00000000003e2050 000000000001635c 000000007eb17be8 000000007eb17c30 Call Trace: (Ý<00000000000162e6>¨ show_trace+0x13a/0x148) Ý<00000000000349ea>¨ __might_sleep+0x13a/0x164 Ý<0000000000050300>¨ proc_dostring+0x134/0x22c Ý<0000000000312b70>¨ nf_log_proc_dostring+0xfc/0x188 Ý<0000000000136f5e>¨ proc_sys_call_handler+0xf6/0x118 Ý<0000000000136fda>¨ proc_sys_read+0x26/0x34 Ý<00000000000d6e9c>¨ vfs_read+0xac/0x158 Ý<00000000000d703e>¨ SyS_read+0x56/0x88 Ý<0000000000027f42>¨ sysc_noemu+0x10/0x16 The code that introduces the bug came in with 17625274 "netfilter: sysctl support of logger choice". There we have this chunk: + rcu_read_lock(); + logger = rcu_dereference(nf_loggers[tindex]); + if (!logger) + table->data = "NONE"; + else + table->data = logger->name; + r = proc_dostring(table, write, filp, buffer, lenp, ppos); + rcu_read_unlock(); proc_dostring() will call copy_from_user() while preemption is disabled because of rcu_read_lock(). Looks like somebody needs to fix this ;) -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html