Steven Rostedt (VMware) 3d9622c12c tracing: Add barrier to trace_printk() buffer nesting modification ... trace_printk() uses 4 buffers, one for each context (normal, softirq, irq and NMI), such that it does not need to worry about one context preempting the other. There's a nesting counter that gets incremented to figure out which buffer to use. If the context gets preempted by another context which calls trace_printk() it will increment the counter and use the next buffer, and restore the counter when it is finished. The problem is that gcc may optimize the modification of the buffer nesting counter and it may not be incremented in memory before the buffer is used. If this happens, and the context gets interrupted by another context, it could pick the same buffer and corrupt the one that is being used. Compiler barriers need to be added after the nesting variable is incremented and before it is decremented to prevent usage of the context buffers by more than one context at the same time. Cc: Andy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Fixes: e2ace00117 ("tracing: Choose static tp_printk buffer by explicit nesting count") Hat-tip-to: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>		2017-09-05 11:54:33 -04:00
..
blktrace.c
bpf_trace.c	bpf: fix bpf_trace_printk on 32 bit archs	2017-08-15 17:32:15 -07:00
ftrace.c	ftrace: Fix memleak when unregistering dynamic ops when tracing disabled	2017-09-01 13:55:49 -04:00
Kconfig
Makefile
power-traces.c
ring_buffer.c	ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPU	2017-08-02 14:23:02 -04:00
ring_buffer_benchmark.c	ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPU	2017-08-02 14:23:02 -04:00
rpm-traces.c
trace.c	tracing: Add barrier to trace_printk() buffer nesting modification	2017-09-05 11:54:33 -04:00
trace.h	tracing: Only have rmmod clear buffers that its events were active in	2017-08-31 17:47:38 -04:00
trace_benchmark.c
trace_benchmark.h
trace_branch.c
trace_clock.c
trace_entries.h
trace_event_perf.c
trace_events.c	tracing: Only have rmmod clear buffers that its events were active in	2017-08-31 17:47:38 -04:00
trace_events_filter.c	tracing: Fix freeing of filter in create_filter() when set_str is false	2017-08-24 10:07:38 -04:00
trace_events_filter_test.h
trace_events_hist.c
trace_events_trigger.c
trace_export.c
trace_functions.c
trace_functions_graph.c
trace_hwlat.c
trace_irqsoff.c
trace_kdb.c
trace_kprobe.c	A few more minor updates:	2017-07-13 13:17:19 -07:00
trace_mmiotrace.c
trace_nop.c
trace_output.c
trace_output.h
trace_printk.c
trace_probe.c
trace_probe.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest.c	ftrace: Fix selftest goto location on error	2017-09-01 12:04:09 -04:00
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c	tracing: Do note expose stack_trace_filter without DYNAMIC_FTRACE	2017-07-11 19:21:04 -04:00
trace_stat.c
trace_stat.h
trace_syscalls.c
trace_uprobe.c
tracing_map.c	tracing: Fix kmemleak in tracing_map_array_free()	2017-08-24 10:05:51 -04:00
tracing_map.h