Steven Rostedt (VMware) 11f5efc3ab tracing: Add a vmalloc_sync_mappings() for safe measure ... x86_64 lazily maps in the vmalloc pages, and the way this works with per_cpu areas can be complex, to say the least. Mappings may happen at boot up, and if nothing synchronizes the page tables, those page mappings may not be synced till they are used. This causes issues for anything that might touch one of those mappings in the path of the page fault handler. When one of those unmapped mappings is touched in the page fault handler, it will cause another page fault, which in turn will cause a page fault, and leave us in a loop of page faults. Commit 763802b53a ("x86/mm: split vmalloc_sync_all()") split vmalloc_sync_all() into vmalloc_sync_unmappings() and vmalloc_sync_mappings(), as on system exit, it did not need to do a full sync on x86_64 (although it still needed to be done on x86_32). By chance, the vmalloc_sync_all() would synchronize the page mappings done at boot up and prevent the per cpu area from being a problem for tracing in the page fault handler. But when that synchronization in the exit of a task became a nop, it caused the problem to appear. Link: https://lore.kernel.org/r/20200429054857.66e8e333@oasis.local.home Cc: stable@vger.kernel.org Fixes: 737223fbca ("tracing: Consolidate buffer allocation code") Reported-by: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> Suggested-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>		2020-05-07 13:32:57 -04:00
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blktrace.c	blktrace: fix dereference after null check	2020-03-05 13:42:40 -07:00
bpf_trace.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2020-03-30 19:52:37 -07:00
fgraph.c
ftrace_internal.h
ftrace.c	ftrace: Fix memory leak caused by not freeing entry in unregister_ftrace_direct()	2020-04-22 22:04:27 -04:00
Kconfig
kprobe_event_gen_test.c
Makefile
power-traces.c
preemptirq_delay_test.c	tracing: Wait for preempt irq delay thread to finish	2020-05-07 13:32:40 -04:00
ring_buffer_benchmark.c
ring_buffer.c	ring-buffer/tracing: Have iterator acknowledge dropped events	2020-03-27 16:39:01 -04:00
rpm-traces.c
synth_event_gen_test.c
trace_benchmark.c
trace_benchmark.h
trace_boot.c	tracing/boottime: Fix kprobe event API usage	2020-05-06 09:04:11 -04:00
trace_branch.c
trace_clock.c
trace_dynevent.c
trace_dynevent.h
trace_entries.h	tracing: Have hwlat ts be first instance and record count of instances	2020-03-03 17:33:43 -05:00
trace_event_perf.c
trace_events_filter_test.h
trace_events_filter.c
trace_events_hist.c	tracing: Fix memory leaks in trace_events_hist.c	2020-04-22 21:24:00 -04:00
trace_events_inject.c
trace_events_trigger.c	tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation	2020-04-14 22:02:10 -04:00
trace_events.c	tracing: Create set_event_notrace_pid to not trace tasks	2020-03-27 16:39:02 -04:00
trace_export.c
trace_functions_graph.c	ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance()	2020-03-19 19:11:19 -04:00
trace_functions.c
trace_hwlat.c	tracing: Have hwlat ts be first instance and record count of instances	2020-03-03 17:33:43 -05:00
trace_irqsoff.c
trace_kdb.c
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_kprobe.c	tracing/kprobes: Reject new event if loc is NULL	2020-05-06 09:04:11 -04:00
trace_mmiotrace.c
trace_nop.c
trace_output.c	tracing: Save off entry when peeking at next entry	2020-03-19 17:48:36 -04:00
trace_output.h
trace_preemptirq.c
trace_printk.c
trace_probe_tmpl.h
trace_probe.c
trace_probe.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest_dynamic.c
trace_selftest.c
trace_seq.c
trace_stack.c
trace_stat.c
trace_stat.h
trace_syscalls.c
trace_uprobe.c
trace.c	tracing: Add a vmalloc_sync_mappings() for safe measure	2020-05-07 13:32:57 -04:00
trace.h	tracing: Create set_event_notrace_pid to not trace tasks	2020-03-27 16:39:02 -04:00
tracing_map.c	tracing: Convert local functions in tracing_map.c to static	2020-04-22 22:07:26 -04:00
tracing_map.h