Steven Rostedt (VMware) 7da261e6bb tracing / histogram: Give calculation hist_fields a size ... commit 2c05caa7ba upstream. When working on my user space applications, I found a bug in the synthetic event code where the automated synthetic event field was not matching the event field calculation it was attached to. Looking deeper into it, it was because the calculation hist_field was not given a size. The synthetic event fields are matched to their hist_fields either by having the field have an identical string type, or if that does not match, then the size and signed values are used to match the fields. The problem arose when I tried to match a calculation where the fields were "unsigned int". My tool created a synthetic event of type "u32". But it failed to match. The string was: diff=field1-field2:onmatch(event).trace(synth,$diff) Adding debugging into the kernel, I found that the size of "diff" was 0. And since it was given "unsigned int" as a type, the histogram fallback code used size and signed. The signed matched, but the size of u32 (4) did not match zero, and the event failed to be created. This can be worse if the field you want to match is not one of the acceptable fields for a synthetic event. As event fields can have any type that is supported in Linux, this can cause an issue. For example, if a type is an enum. Then there's no way to use that with any calculations. Have the calculation field simply take on the size of what it is calculating. Link: https://lkml.kernel.org/r/20210730171951.59c7743f@oasis.local.home Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: 100719dcef ("tracing: Add simple expression support to hist triggers") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-08-12 13:21:00 +02:00
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blktrace.c	blktrace: ensure our debugfs dir exists	2020-09-03 11:26:42 +02:00
bpf_trace.c	tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing	2021-07-14 16:53:08 +02:00
fgraph.c	fgraph: Initialize tracing_graph_pause at task creation	2021-02-10 09:25:29 +01:00
ftrace.c	ftrace: Do not blindly read the ip address in ftrace_bug()	2021-06-16 11:59:45 +02:00
ftrace_internal.h
Kconfig	tracing/kprobes: Do the notrace functions check without kprobes on ftrace	2021-01-19 18:26:12 +01:00
Makefile
power-traces.c
preemptirq_delay_test.c
ring_buffer.c	tracing: Fix bug in rb_per_cpu_empty() that might cause deadloop.	2021-07-28 13:31:00 +02:00
ring_buffer_benchmark.c
rpm-traces.c
trace.c	tracing/histogram: Rename "cpu" to "common_cpu"	2021-07-28 13:31:00 +02:00
trace.h	ftrace: Handle tracing when switching between context	2020-11-10 12:37:28 +01:00
trace_benchmark.c
trace_benchmark.h
trace_branch.c
trace_clock.c	tracing: Do no increment trace_clock_global() by one	2021-06-23 14:41:28 +02:00
trace_dynevent.c
trace_dynevent.h
trace_entries.h	tracing: Set kernel_stack's caller size properly	2020-10-01 13:17:29 +02:00
trace_event_perf.c
trace_events.c	tracing: Do not count ftrace events in top level enable output	2021-02-17 10:35:14 +01:00
trace_events_filter.c
trace_events_filter_test.h
trace_events_hist.c	tracing / histogram: Give calculation hist_fields a size	2021-08-12 13:21:00 +02:00
trace_events_trigger.c	tracing: Fix event trigger to accept redundant spaces	2020-06-30 15:37:10 -04:00
trace_export.c
trace_functions.c
trace_functions_graph.c
trace_hwlat.c	tracing: Remove WARN_ON in start_thread()	2020-12-08 10:40:28 +01:00
trace_irqsoff.c
trace_kdb.c
trace_kprobe.c	tracing/kprobe: Fix to support kretprobe events on unloaded modules	2021-02-13 13:52:54 +01:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c
trace_nop.c
trace_output.c	tracing: Make the space reserved for the pid wider	2020-10-07 08:01:27 +02:00
trace_output.h
trace_preemptirq.c	lockdep: fix order in trace_hardirqs_off_caller()	2020-10-01 13:18:14 +02:00
trace_printk.c
trace_probe.c	tracing/probe: Fix memleak in fetch_op_data operations	2020-06-24 17:50:51 +02:00
trace_probe.h
trace_probe_tmpl.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest.c	ftrace: Handle tracing when switching between context	2020-11-10 12:37:28 +01:00
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c
trace_stat.c
trace_stat.h
trace_syscalls.c
trace_uprobe.c	tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobes	2020-06-24 17:50:43 +02:00
tracing_map.c
tracing_map.h