linux/kernel/trace
Steven Rostedt (Red Hat) ca1643186d tracing: Fix crash when ftrace=nop on the kernel command line
If ftrace=<tracer> is on the kernel command line, when that tracer is
registered, it will be initiated by tracing_set_tracer() to execute that
tracer.

The nop tracer is just a stub tracer that is used to have no tracer
enabled. It is assigned at early bootup as it is the default tracer.

But if ftrace=nop is on the kernel command line, the registering of the
nop tracer will call tracing_set_tracer() which will try to execute
the nop tracer. But it expects tr->current_trace to be assigned something
as it usually is assigned to the nop tracer. As it hasn't been assigned
to anything yet, it causes the system to crash.

The simple fix is to move the tr->current_trace = nop before registering
the nop tracer. The functionality is still the same as the nop tracer
doesn't do anything anyway.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-05-23 11:57:25 -04:00
..
blktrace.c Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block 2013-05-08 11:51:05 -07:00
ftrace.c ftrace: Fix function probe when more than one probe is added 2013-05-09 20:16:27 -04:00
Kconfig ring-buffer: Select IRQ_WORK 2013-05-03 19:24:17 -04:00
Makefile trace: Stop compiling in trace_clock unconditionally 2012-09-13 22:52:08 -04:00
power-traces.c PM / tracing: remove deprecated power trace API 2013-01-26 00:39:12 +01:00
ring_buffer_benchmark.c tracing: Use NUMA allocation for per-cpu ring buffer pages 2011-06-14 22:04:39 -04:00
ring_buffer.c Tracing updates for Linux 3.10 2013-04-29 13:55:38 -07:00
rpm-traces.c PM / Runtime: Introduce trace points for tracing rpm_* functions 2011-09-27 22:53:27 +02:00
trace_branch.c tracing: Fix the branch tracer that broke with buffer change 2013-03-15 00:35:54 -04:00
trace_clock.c tracing: Add "uptime" trace clock that uses jiffies 2013-03-15 00:36:09 -04:00
trace_entries.h tracing: Add trace_puts() for even faster trace_printk() tracing 2013-03-15 00:35:55 -04:00
trace_event_perf.c perf/core improvements and fixes: 2012-08-21 11:27:00 +02:00
trace_events_filter_test.h tracing/filter: Add startup tests for events filter 2011-08-19 14:35:59 -04:00
trace_events_filter.c tracing: Fix leaks of filter preds 2013-05-15 13:49:18 -04:00
trace_events.c tracing: Return -EBUSY when event_enable_func() fails to get module 2013-05-16 11:01:16 -04:00
trace_export.c tracing: Fix some section mismatch warnings 2013-03-15 00:34:54 -04:00
trace_functions_graph.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_functions.c tracing: Add function probe to trigger stack traces 2013-03-15 00:36:05 -04:00
trace_irqsoff.c tracing: Add function-trace option to disable function tracing of latency tracers 2013-03-15 00:36:08 -04:00
trace_kdb.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_kprobe.c tracing/kprobes: Make print_*probe_event static 2013-05-15 13:50:24 -04:00
trace_mmiotrace.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_nop.c
trace_output.c Tracing updates for Linux 3.10 2013-04-29 13:55:38 -07:00
trace_output.h tracing: Rename trace_event_mutex to trace_event_sem 2013-03-15 13:22:10 -04:00
trace_printk.c tracing: Add percpu buffers for trace_printk() 2012-04-23 21:15:55 -04:00
trace_probe.c tracing: Replace strict_strto* with kstrto* 2012-10-31 16:45:23 -04:00
trace_probe.h uprobes/tracing: Introduce is_trace_uprobe_enabled() 2013-02-08 18:24:30 +01:00
trace_sched_switch.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_sched_wakeup.c tracing: Add function-trace option to disable function tracing of latency tracers 2013-03-15 00:36:08 -04:00
trace_selftest_dynamic.c ftrace: Add self-tests for multiple function trace users 2011-05-18 19:24:51 -04:00
trace_selftest.c tracing: Fix ftrace_dump() 2013-03-15 19:24:56 -04:00
trace_stack.c Tracing updates for Linux 3.10 2013-04-29 13:55:38 -07:00
trace_stat.c tracing: Check return value of tracing_init_dentry() 2013-04-12 23:02:32 -04:00
trace_stat.h
trace_syscalls.c tracing: Fix comment about prefix in arch_syscall_match_sym_name() 2013-03-15 13:22:09 -04:00
trace_uprobe.c uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty 2013-04-15 17:39:52 +02:00
trace.c tracing: Fix crash when ftrace=nop on the kernel command line 2013-05-23 11:57:25 -04:00
trace.h Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-30 07:41:01 -07:00