remarkable-linux/kernel/trace
Naveen N. Rao a0e6369e4b 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>
2017-05-17 21:52:22 -04:00
..
blktrace.c block: remove the errors field from struct request 2017-04-20 12:16:10 -06:00
bpf_trace.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-05-02 16:40:27 -07:00
ftrace.c ftrace/instances: Clear function triggers when removing instances 2017-05-17 21:52:22 -04:00
Kconfig New features for this release: 2017-05-03 18:41:21 -07:00
Makefile
power-traces.c
ring_buffer.c New features for this release: 2017-05-03 18:41:21 -07:00
ring_buffer_benchmark.c ring-buffer: Return reader page back into existing ring buffer 2017-05-01 10:26:40 -04:00
rpm-traces.c
trace.c ftrace/instances: Clear function triggers when removing instances 2017-05-17 21:52:22 -04:00
trace.h ftrace/instances: Clear function triggers when removing instances 2017-05-17 21:52:22 -04:00
trace_benchmark.c tracing: Have the trace_event benchmark thread call cond_resched_rcu_qs() 2017-04-17 15:21:19 -04:00
trace_benchmark.h
trace_branch.c
trace_clock.c
trace_entries.h trace: make trace_hwlat timestamp y2038 safe 2017-05-08 17:15:15 -07:00
trace_event_perf.c
trace_events.c tracing/ftrace: Add a better way to pass data via the probe functions 2017-04-20 22:06:46 -04:00
trace_events_filter.c
trace_events_filter_test.h
trace_events_hist.c sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h> 2017-03-02 08:42:38 +01:00
trace_events_trigger.c sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h> 2017-03-02 08:42:38 +01:00
trace_export.c
trace_functions.c tracing/ftrace: Allow for instances to trigger their own stacktrace probes 2017-04-20 22:06:49 -04:00
trace_functions_graph.c
trace_hwlat.c trace: make trace_hwlat timestamp y2038 safe 2017-05-08 17:15:15 -07:00
trace_irqsoff.c
trace_kdb.c
trace_kprobe.c tracing/kprobes: Enforce kprobes teardown after testing 2017-05-17 21:50:27 -04:00
trace_mmiotrace.c
trace_nop.c
trace_output.c trace: make trace_hwlat timestamp y2038 safe 2017-05-08 17:15:15 -07:00
trace_output.h
trace_printk.c
trace_probe.c
trace_probe.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest.c
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c rcu/tracing: Add rcu_disabled to denote when rcu_irq_enter() will not work 2017-04-10 15:22:03 -04:00
trace_stat.c
trace_stat.h
trace_syscalls.c
trace_uprobe.c sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h> 2017-03-02 08:42:38 +01:00
tracing_map.c
tracing_map.h