Re: [PATCH v4 00/10] tracing: introducing eventfs

Steven Rostedt
2023-07-18T13:40:26Z

On Sun, 16 Jul 2023 17:32:35 +0000
Ajay Kaher <akaher@vmware.com> wrote:

> Thanks Steve, hopefully I will fix all the pending nits in v5.
> Here is the checkpatch.pl report:

Hold off on v5. I hit the following on v4:

[ 220.170527] BUG: unable to handle page fault for address: fffffffffffffff0
[ 220.172792] #PF: supervisor read access in kernel mode
[ 220.174618] #PF: error_code(0x0000) - not-present page
[ 220.176516] PGD 13104d067 P4D 13104d067 PUD 13104f067 PMD 0
[ 220.178559] Oops: 0000 [#1] PREEMPT SMP PTI
[ 220.180087] CPU: 3 PID: 35 Comm: kworker/u8:1 Not tainted 6.5.0-rc1-test-00021-gdd6e7af33766-dirty #15
[ 220.183441] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 220.186629] Workqueue: events_unbound eventfs_workfn
[ 220.188286] RIP: 0010:eventfs_set_ef_status_free+0x17/0x40
[ 220.190091] Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 0f 1f 44 00 00 48 8b 47 18 48 8b 40 30 48 83 f8 10 74 1b <f6> 40 f0 02 74 15 48 8b 47 78 48 85 c0 74 0c c6 40 5a 00 48 c7 40
[ 220.195360] RSP: 0018:ffffa731c0147e20 EFLAGS: 00010287
[ 220.196802] RAX: 0000000000000000 RBX: ffff97ca512ca000 RCX: 0000000000000000
[ 220.198703] RDX: 0000000000000001 RSI: ffff97ca52d18010 RDI: ffff97ca512ca000
[ 220.200540] RBP: ffff97ca52cb3780 R08: 0000000000000064 R09: 00000000802a0022
[ 220.202324] R10: 0000000000039e80 R11: ffff97cabffd5000 R12: ffff97ca512ca058
[ 220.204012] R13: ffff97ca52cb3780 R14: ffff97ca40153705 R15: ffffffffad5c1848
[ 220.205685] FS: 0000000000000000(0000) GS:ffff97cabbd80000(0000) knlGS:0000000000000000
[ 220.207476] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 220.208764] CR2: fffffffffffffff0 CR3: 000000010a01a001 CR4: 0000000000170ee0
[ 220.210342] Call Trace:
[ 220.210879] <TASK>
[ 220.211359] ? __die+0x23/0x70
[ 220.212036] ? page_fault_oops+0xa4/0x180
[ 220.212904] ? exc_page_fault+0xf6/0x190
[ 220.213738] ? asm_exc_page_fault+0x26/0x30
[ 220.214586] ? eventfs_set_ef_status_free+0x17/0x40
[ 220.216081] tracefs_dentry_iput+0x39/0x50
[ 220.217370] __dentry_kill+0xdc/0x170
[ 220.218581] dput+0x142/0x310
[ 220.219647] eventfs_workfn+0x42/0x70
[ 220.220805] process_one_work+0x1e2/0x3e0
[ 220.222031] worker_thread+0x1da/0x390
[ 220.223204] ? __pfx_worker_thread+0x10/0x10
[ 220.224476] kthread+0xf7/0x130
[ 220.225543] ? __pfx_kthread+0x10/0x10
[ 220.226735] ret_from_fork+0x2c/0x50
[ 220.227898] </TASK>
[ 220.228792] Modules linked in:
[ 220.229860] CR2: fffffffffffffff0
[ 220.230960] ---[ end trace 0000000000000000 ]---

I think I know the issue, and looking to see if I can fix it.

-- Steve