Steven Rostedt (VMware) f706acc931 tracing: Fix stack trace event size ... commit 9deb193af69d3fd6dd8e47f292b67c805a787010 upstream. Commit cbc3b92ce0 fixed an issue to modify the macros of the stack trace event so that user space could parse it properly. Originally the stack trace format to user space showed that the called stack was a dynamic array. But it is not actually a dynamic array, in the way that other dynamic event arrays worked, and this broke user space parsing for it. The update was to make the array look to have 8 entries in it. Helper functions were added to make it parse it correctly, as the stack was dynamic, but was determined by the size of the event stored. Although this fixed user space on how it read the event, it changed the internal structure used for the stack trace event. It changed the array size from [0] to [8] (added 8 entries). This increased the size of the stack trace event by 8 words. The size reserved on the ring buffer was the size of the stack trace event plus the number of stack entries found in the stack trace. That commit caused the amount to be 8 more than what was needed because it did not expect the caller field to have any size. This produced 8 entries of garbage (and reading random data) from the stack trace event: <idle>-0 [002] d... 1976396.837549: <stack trace> => trace_event_raw_event_sched_switch => __traceiter_sched_switch => __schedule => schedule_idle => do_idle => cpu_startup_entry => secondary_startup_64_no_verify => 0xc8c5e150ffff93de => 0xffff93de => 0 => 0 => 0xc8c5e17800000000 => 0x1f30affff93de => 0x00000004 => 0x200000000 Instead, subtract the size of the caller field from the size of the event to make sure that only the amount needed to store the stack trace is reserved. Link: https://lore.kernel.org/lkml/your-ad-here.call-01617191565-ext-9692@work.hours/ Cc: stable@vger.kernel.org Fixes: cbc3b92ce0 ("tracing: Set kernel_stack's caller size properly") Reported-by: Vasily Gorbik <gor@linux.ibm.com> Tested-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-04-07 15:00:10 +02:00
..
blktrace.c	block: add a bdget_part helper	2020-10-05 10:38:33 -06:00
bpf_trace.c	bpf: Unbreak BPF_PROG_TYPE_KPROBE when kprobe is called via do_int3	2021-02-17 11:02:25 +01:00
bpf_trace.h
fgraph.c	fgraph: Initialize tracing_graph_pause at task creation	2021-02-10 09:29:16 +01:00
ftrace_internal.h
ftrace.c	ftrace: Fix modify_ftrace_direct.	2021-03-30 14:32:00 +02:00
Kconfig	tracing/kprobes: Do the notrace functions check without kprobes on ftrace	2021-01-19 18:27:19 +01:00
kprobe_event_gen_test.c
Makefile
power-traces.c
preemptirq_delay_test.c
ring_buffer_benchmark.c
ring_buffer.c	ring-buffer: Force before_stamp and write_stamp to be different on discard	2021-03-09 11:11:12 +01:00
rpm-traces.c
synth_event_gen_test.c	tracing: Add support for dynamic strings to synthetic events	2020-10-05 19:32:18 -04:00
trace_benchmark.c
trace_benchmark.h
trace_boot.c	tracing: Disable ftrace selftests when any tracer is running	2020-12-30 11:54:28 +01:00
trace_branch.c
trace_clock.c
trace_dynevent.c
trace_dynevent.h
trace_entries.h
trace_event_perf.c
trace_events_filter_test.h
trace_events_filter.c
trace_events_hist.c	tracing: Check return value of __create_val_fields() before using its result	2020-10-15 12:00:59 -04:00
trace_events_inject.c
trace_events_synth.c	tracing: Make -ENOMEM the default error for parse_synth_field()	2020-11-02 15:58:32 -05:00
trace_events_trigger.c
trace_events.c	tracing: Do not count ftrace events in top level enable output	2021-02-17 11:02:20 +01:00
trace_export.c	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
trace_functions_graph.c
trace_functions.c
trace_hwlat.c	tracing: Remove WARN_ON in start_thread()	2020-11-30 21:43:07 -05:00
trace_irqsoff.c	tracing: Use pause-on-trace with the latency tracers	2021-02-10 09:29:16 +01:00
trace_kdb.c
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_kprobe.c	tracing/kprobe: Fix to support kretprobe events on unloaded modules	2021-02-10 09:29:16 +01:00
trace_mmiotrace.c
trace_nop.c
trace_output.c
trace_output.h
trace_preemptirq.c
trace_printk.c	Updates for tracing and bootconfig:	2020-10-15 15:51:28 -07:00
trace_probe_tmpl.h
trace_probe.c
trace_probe.h	tracing: Move is_good_name() from trace_probe.h to trace.h	2020-10-15 12:01:13 -04:00
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest_dynamic.c
trace_selftest.c	tracing: Disable ftrace selftests when any tracer is running	2020-12-30 11:54:28 +01:00
trace_seq.c
trace_stack.c
trace_stat.c
trace_stat.h
trace_synth.h	tracing: Add support for dynamic strings to synthetic events	2020-10-05 19:32:18 -04:00
trace_syscalls.c
trace_uprobe.c
trace.c	tracing: Fix stack trace event size	2021-04-07 15:00:10 +02:00
trace.h	tracing: Disable ftrace selftests when any tracer is running	2020-12-30 11:54:28 +01:00
tracing_map.c
tracing_map.h