From 2ca310fc4160ed0420da65534a21ae77b24326a8 Mon Sep 17 00:00:00 2001 From: Ditang Chen Date: Fri, 7 Mar 2014 13:27:57 +0800 Subject: [PATCH] SUNRPC: Fix oops when trace sunrpc_task events in nfs client When tracking sunrpc_task events in nfs client, the clnt pointer may be NULL. [ 139.269266] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 139.269915] IP: [] ftrace_raw_event_rpc_task_running+0x86/0xf0 [sunrpc] [ 139.269915] PGD 1d293067 PUD 1d294067 PMD 0 [ 139.269915] Oops: 0000 [#1] SMP [ 139.269915] Modules linked in: nfsv4 dns_resolver nfs lockd sunrpc fscache sg ppdev e1000 serio_raw pcspkr parport_pc parport i2c_piix4 i2c_core microcode xfs libcrc32c sd_mod sr_mod cdrom ata_generic crc_t10dif crct10dif_common pata_acpi ahci libahci ata_piix libata dm_mirror dm_region_hash dm_log dm_mod [ 139.269915] CPU: 0 PID: 59 Comm: kworker/0:2 Not tainted 3.10.0-84.el7.x86_64 #1 [ 139.269915] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 139.269915] Workqueue: rpciod rpc_async_schedule [sunrpc] [ 139.269915] task: ffff88001b598000 ti: ffff88001b632000 task.ti: ffff88001b632000 [ 139.269915] RIP: 0010:[] [] ftrace_raw_event_rpc_task_running+0x86/0xf0 [sunrpc] [ 139.269915] RSP: 0018:ffff88001b633d70 EFLAGS: 00010206 [ 139.269915] RAX: ffff88001dfc5338 RBX: ffff88001cc37a00 RCX: ffff88001dfc5334 [ 139.269915] RDX: ffff88001dfc5338 RSI: 0000000000000000 RDI: ffff88001dfc533c [ 139.269915] RBP: ffff88001b633db0 R08: 000000000000002c R09: 000000000000000a [ 139.269915] R10: 0000000000062180 R11: 00000020759fb9dc R12: ffffffffa0292c20 [ 139.269915] R13: ffff88001dfc5334 R14: 0000000000000000 R15: 0000000000000000 [ 139.269915] FS: 0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000 [ 139.269915] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 139.269915] CR2: 0000000000000004 CR3: 000000001d290000 CR4: 00000000000006f0 [ 139.269915] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 139.269915] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 139.269915] Stack: [ 139.269915] 000000001b633d98 0000000000000246 ffff88001df1dc00 ffff88001cc37a00 [ 139.269915] ffff88001bc35e60 0000000000000000 ffff88001ffa0a48 ffff88001bc35ee0 [ 139.269915] ffff88001b633e08 ffffffffa02704b5 0000000000010000 ffff88001cc37a70 [ 139.269915] Call Trace: [ 139.269915] [] __rpc_execute+0x1d5/0x400 [sunrpc] [ 139.269915] [] rpc_async_schedule+0x26/0x30 [sunrpc] [ 139.269915] [] process_one_work+0x17b/0x460 [ 139.269915] [] worker_thread+0x11b/0x400 [ 139.269915] [] ? rescuer_thread+0x3e0/0x3e0 [ 139.269915] [] kthread+0xc0/0xd0 [ 139.269915] [] ? kthread_create_on_node+0x110/0x110 [ 139.269915] [] ret_from_fork+0x7c/0xb0 [ 139.269915] [] ? kthread_create_on_node+0x110/0x110 [ 139.269915] Code: 4c 8b 45 c8 48 8d 7d d0 89 4d c4 41 89 c9 b9 28 00 00 00 e8 9d b4 e9 e0 48 85 c0 49 89 c5 74 a2 48 89 c7 e8 9d 3f e9 e0 48 89 c2 <41> 8b 46 04 48 8b 7d d0 4c 89 e9 4c 89 e6 89 42 0c 0f b7 83 d4 [ 139.269915] RIP [] ftrace_raw_event_rpc_task_running+0x86/0xf0 [sunrpc] [ 139.269915] RSP [ 139.269915] CR2: 0000000000000004 [ 140.946406] ---[ end trace ba486328b98d7622 ]--- Signed-off-by: Ditang Chen Signed-off-by: Trond Myklebust --- include/trace/events/sunrpc.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index ddc179b7a105..1fef3e6e9436 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -83,7 +83,7 @@ DECLARE_EVENT_CLASS(rpc_task_running, ), TP_fast_assign( - __entry->client_id = clnt->cl_clid; + __entry->client_id = clnt ? clnt->cl_clid : -1; __entry->task_id = task->tk_pid; __entry->action = action; __entry->runstate = task->tk_runstate; @@ -91,7 +91,7 @@ DECLARE_EVENT_CLASS(rpc_task_running, __entry->flags = task->tk_flags; ), - TP_printk("task:%u@%u flags=%4.4x state=%4.4lx status=%d action=%pf", + TP_printk("task:%u@%d flags=%4.4x state=%4.4lx status=%d action=%pf", __entry->task_id, __entry->client_id, __entry->flags, __entry->runstate, -- GitLab