Steven Rostedt (VMware) c9d01b9fb5 ftrace: Handle tracing when switching between context ... commit 726b3d3f141fba6f841d715fc4d8a4a84f02c02a upstream. When an interrupt or NMI comes in and switches the context, there's a delay from when the preempt_count() shows the update. As the preempt_count() is used to detect recursion having each context have its own bit get set when tracing starts, and if that bit is already set, it is considered a recursion and the function exits. But if this happens in that section where context has changed but preempt_count() has not been updated, this will be incorrectly flagged as a recursion. To handle this case, create another bit call TRANSITION and test it if the current context bit is already set. Flag the call as a recursion if the TRANSITION bit is already set, and if not, set it and continue. The TRANSITION bit will be cleared normally on the return of the function that set it, or if the current context bit is clear, set it and clear the TRANSITION bit to allow for another transition between the current context and an even higher one. Cc: stable@vger.kernel.org Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-03-16 16:40:23 +08:00
..
Kconfig	Stop the ad-hoc games with -Wno-maybe-initialized	2021-03-16 16:27:58 +08:00
Makefile	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blktrace.c	blktrace: ensure our debugfs dir exists	2021-03-16 16:34:47 +08:00
bpf_trace.c	bpf: Fix deadlock with rq_lock in bpf_send_signal()	2021-03-16 16:25:53 +08:00
fgraph.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
ftrace.c	ftrace: Move RCU is watching check after recursion check	2021-03-16 16:37:44 +08:00
ftrace_internal.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
power-traces.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
preemptirq_delay_test.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
ring_buffer.c	ring-buffer: Fix recursion protection transitions between interrupt context	2021-03-16 16:40:22 +08:00
ring_buffer_benchmark.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
rpm-traces.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace.c	tracing: Make the space reserved for the pid wider	2021-03-16 16:37:46 +08:00
trace.h	ftrace: Handle tracing when switching between context	2021-03-16 16:40:23 +08:00
trace_benchmark.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_benchmark.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_branch.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_clock.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_dynevent.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_dynevent.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_entries.h	tracing: Set kernel_stack's caller size properly	2021-03-16 16:36:48 +08:00
trace_event_perf.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_events.c	tracing: Adding NULL checks for trace_array descriptor pointer	2021-03-16 16:36:38 +08:00
trace_events_filter.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_events_filter_test.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_events_hist.c	tracing: fix double free	2021-03-16 16:37:39 +08:00
trace_events_trigger.c	tracing: Fix event trigger to accept redundant spaces	2021-03-16 16:31:10 +08:00
trace_export.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_functions.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_functions_graph.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_hwlat.c	tracing/hwlat: Honor the tracing_cpumask	2021-03-16 16:34:08 +08:00
trace_irqsoff.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_kdb.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_kprobe.c	tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobes	2021-03-16 16:30:34 +08:00
trace_kprobe_selftest.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_kprobe_selftest.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_mmiotrace.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_nop.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_output.c	tracing: Make the space reserved for the pid wider	2021-03-16 16:37:46 +08:00
trace_output.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_preemptirq.c	lockdep: fix order in trace_hardirqs_off_caller()	2021-03-16 16:37:31 +08:00
trace_printk.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_probe.c	tracing/probe: Fix memleak in fetch_op_data operations	2021-03-16 16:30:43 +08:00
trace_probe.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_probe_tmpl.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_sched_switch.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_sched_wakeup.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_selftest.c	ftrace: Handle tracing when switching between context	2021-03-16 16:40:23 +08:00
trace_selftest_dynamic.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_seq.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_stack.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_stat.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_stat.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_syscalls.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
trace_uprobe.c	tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobes	2021-03-16 16:30:34 +08:00
tracing_map.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
tracing_map.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00