linux/kernel/trace
Kalesh Singh 9710b2f341 tracing: Fix operator precedence for hist triggers expression
The current histogram expression evaluation logic evaluates the
expression from right to left. This can lead to incorrect results
if the operations are not associative (as is the case for subtraction
and, the now added, division operators).
	e.g. 16-8-4-2 should be 2 not 10 --> 16-8-4-2 = ((16-8)-4)-2
	     64/8/4/2 should be 1 not 16 --> 64/8/4/2 = ((64/8)/4)/2

Division and multiplication are currently limited to single operation
expression due to operator precedence support not yet implemented.

Rework the expression parsing to support the correct evaluation of
expressions containing operators of different precedences; and fix
the associativity error by evaluating expressions with operators of
the same precedence from left to right.

Examples:
        (1) echo 'hist:keys=common_pid:a=8,b=4,c=2,d=1,w=$a-$b-$c-$d' \
                  >> event/trigger
        (2) echo 'hist:keys=common_pid:x=$a/$b/3/2' >> event/trigger
        (3) echo 'hist:keys=common_pid:y=$a+10/$c*1024' >> event/trigger
        (4) echo 'hist:keys=common_pid:z=$a/$b+$c*$d' >> event/trigger

Link: https://lkml.kernel.org/r/20211025200852.3002369-4-kaleshsingh@google.com

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26 20:27:19 -04:00
..
blktrace.c blktrace: Fix uaf in blk_trace access after removing by sysfs 2021-09-24 11:06:15 -06:00
bpf_trace.c bpf: Fix bpf-next builds without CONFIG_BPF_EVENTS 2021-08-25 19:41:39 -07:00
bpf_trace.h bpf: Use dedicated bpf_trace_printk event instead of trace_printk() 2020-07-13 16:55:49 -07:00
error_report-traces.c tracing: add error_report_end trace point 2021-02-26 09:41:02 -08:00
fgraph.c x86/ftrace: Make function graph use ftrace directly 2021-10-20 23:44:43 -04:00
ftrace_internal.h x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up 2020-05-12 18:24:34 -04:00
ftrace.c ftrace: Make ftrace_profile_pages_init static 2021-10-25 22:27:07 -04:00
Kconfig tracing: Simplify the Kconfig dependency of FTRACE 2021-08-16 11:37:20 -04:00
kprobe_event_gen_test.c
Makefile tracing: Place trace_pid_list logic into abstract functions 2021-10-05 17:30:08 -04:00
pid_list.c tracing: Initialize upper and lower vars in pid_list_refill_irq() 2021-10-07 09:56:38 -04:00
pid_list.h tracing: Create a sparse bitmask for pid filtering 2021-10-05 17:38:45 -04:00
power-traces.c
preemptirq_delay_test.c kernel: trace: preemptirq_delay_test: add cpu affinity 2021-02-02 17:02:07 -05:00
ring_buffer_benchmark.c sched,tracing: Convert to sched_set_fifo() 2020-07-29 11:43:53 +02:00
ring_buffer.c tracing/perf: Add interrupt_context_level() helper 2021-10-19 20:33:20 -04:00
rpm-traces.c
synth_event_gen_test.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_benchmark.c tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00
trace_benchmark.h
trace_boot.c tracing: Fix missing trace_boot_init_histograms kstrdup NULL checks 2021-10-26 09:18:10 -04:00
trace_branch.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_clock.c tracing: Do no increment trace_clock_global() by one 2021-06-18 09:10:00 -04:00
trace_dynevent.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_dynevent.h tracing: Add DYNAMIC flag for dynamic events 2021-08-18 18:10:32 -04:00
trace_entries.h trace: Add timerlat tracer 2021-06-25 19:57:24 -04:00
trace_eprobe.c tracing: Fix some alloc_event_probe() error handling bugs 2021-09-07 20:58:23 -04:00
trace_event_perf.c tracing: Have dynamic events have a ref counter 2021-08-18 18:13:47 -04:00
trace_events_filter_test.h
trace_events_filter.c tracing: Update create_system_filter() kernel-doc comment 2021-03-25 16:04:35 -04:00
trace_events_hist.c tracing: Fix operator precedence for hist triggers expression 2021-10-26 20:27:19 -04:00
trace_events_inject.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_events_synth.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_events_trigger.c tracing: Add a probe that attaches to trace events 2021-08-20 14:18:40 -04:00
trace_events.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_export.c tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00
trace_functions_graph.c tracing: in_irq() cleanup 2021-10-13 18:19:41 -04:00
trace_functions.c tracing: Add "func_no_repeats" option for function tracing 2021-04-15 14:50:02 -04:00
trace_hwlat.c tracing/hwlat: Make some internal symbols static 2021-10-26 09:18:28 -04:00
trace_irqsoff.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_kdb.c kdb: Rename members of struct kdbtab_t 2021-07-27 17:05:06 +01:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_kprobe.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_mmiotrace.c tracing: Remove definition of DEBUG in trace_mmiotrace.c 2021-02-02 17:02:07 -05:00
trace_nop.c
trace_osnoise.c trace/timerlat: Add migrate-disabled field to the timerlat header 2021-10-25 23:02:36 -04:00
trace_output.c tracing: Show kretprobe unknown indicator only for kretprobe_trampoline 2021-09-30 21:24:08 -04:00
trace_output.h ftrace: Add recording of functions that caused recursion 2020-11-06 08:42:26 -05:00
trace_preemptirq.c lockdep: fix order in trace_hardirqs_off_caller() 2020-09-14 10:08:07 +02:00
trace_printk.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_probe_tmpl.h tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs 2021-08-19 09:09:03 -04:00
trace_probe.c tracing: Add a probe that attaches to trace events 2021-08-20 14:18:40 -04:00
trace_probe.h tracing: Add a probe that attaches to trace events 2021-08-20 14:18:40 -04:00
trace_recursion_record.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_sched_switch.c
trace_sched_wakeup.c tracing: Change variable type as bool for clean-up 2021-06-30 09:19:14 -04:00
trace_selftest_dynamic.c
trace_selftest.c tracing: Fix selftest config check for function graph start up test 2021-10-21 14:18:48 -04:00
trace_seq.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_stack.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_stat.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_stat.h
trace_synth.h tracing: synth events: increase max fields count 2021-09-08 15:29:16 -04:00
trace_syscalls.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_uprobe.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace.h tracing: in_irq() cleanup 2021-10-13 18:19:41 -04:00
tracing_map.c tracing/cfi: Fix cmp_entries_* functions signature mismatch 2021-10-19 20:33:20 -04:00
tracing_map.h tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00