Commits
Naveen N. Rao committed a0e6369e4ba
ftrace/instances: Clear function triggers when removing instances
If instance directories are deleted while there are registered function
triggers:
# cd /sys/kernel/debug/tracing/instances
# mkdir test
# echo "schedule:enable_event:sched:sched_switch" > test/set_ftrace_filter
# rmdir test
Unable to handle kernel paging request for data at address 0x00000008
Unable to handle kernel paging request for data at address 0x00000008
Faulting instruction address: 0xc0000000021edde8
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2048
NUMA
pSeries
Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc kvm iptable_filter fuse binfmt_misc pseries_rng rng_core vmx_crypto ib_iser rdma_cm iw_cm ib_cm ib_core libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c multipath virtio_net virtio_blk virtio_pci crc32c_vpmsum virtio_ring virtio
CPU: 8 PID: 8694 Comm: rmdir Not tainted 4.11.0-nnr+ #113
task: c0000000bab52800 task.stack: c0000000baba0000
NIP: c0000000021edde8 LR: c0000000021f0590 CTR: c000000002119620
REGS: c0000000baba3870 TRAP: 0300 Not tainted (4.11.0-nnr+)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE>
CR: 22002422 XER: 20000000
CFAR: 00007fffabb725a8 DAR: 0000000000000008 DSISR: 40000000 SOFTE: 0
GPR00: c00000000220f750 c0000000baba3af0 c000000003157e00 0000000000000000
GPR04: 0000000000000040 00000000000000eb 0000000000000040 0000000000000000
GPR08: 0000000000000000 0000000000000113 0000000000000000 c00000000305db98
GPR12: c000000002119620 c00000000fd42c00 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 c0000000bab52e90 0000000000000000
GPR24: 0000000000000000 00000000000000eb 0000000000000040 c0000000baba3bb0
GPR28: c00000009cb06eb0 c0000000bab52800 c00000009cb06eb0 c0000000baba3bb0
NIP [c0000000021edde8] ring_buffer_lock_reserve+0x8/0x4e0
LR [c0000000021f0590] trace_event_buffer_lock_reserve+0xe0/0x1a0
Call Trace:
[c0000000baba3af0] [c0000000021f96c8] trace_event_buffer_commit+0x1b8/0x280 (unreliable)
[c0000000baba3b60] [c00000000220f750] trace_event_buffer_reserve+0x80/0xd0
[c0000000baba3b90] [c0000000021196b8] trace_event_raw_event_sched_switch+0x98/0x180
[c0000000baba3c10] [c0000000029d9980] __schedule+0x6e0/0xab0
[c0000000baba3ce0] [c000000002122230] do_task_dead+0x70/0xc0
[c0000000baba3d10] [c0000000020ea9c8] do_exit+0x828/0xd00
[c0000000baba3dd0] [c0000000020eaf70] do_group_exit+0x60/0x100
[c0000000baba3e10] [c0000000020eb034] SyS_exit_group+0x24/0x30
[c0000000baba3e30] [c00000000200bcec] system_call+0x38/0x54
Instruction dump:
60000000 60420000 7d244b78 7f63db78 4bffaa09 393efff8 793e0020 39200000
4bfffecc 60420000 3c4c00f7 3842a020 <81230008> 2f890000 409e02f0 a14d0008
---[ end trace b917b8985d0e650b ]---
Unable to handle kernel paging request for data at address 0x00000008
Faulting instruction address: 0xc0000000021edde8
Unable to handle kernel paging request for data at address 0x00000008
Faulting instruction address: 0xc0000000021edde8
Faulting instruction address: 0xc0000000021edde8
To address this, let's clear all registered function probes before
deleting the ftrace instance.
Link: http://lkml.kernel.org/r/c5f1ca624043690bd94642bb6bffd3f2fc504035.1494956770.git.naveen.n.rao@linux.vnet.ibm.com
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>