linux/kernel/trace/trace_events_hist.c, branch v4.19

tracing: Fix synthetic event to allow semicolon at end

2018-10-19T21:25:11Z

Fix synthetic event to allow independent semicolon at end. The synthetic_events interface accepts a semicolon after the last word if there is no space. # echo "myevent u64 var;" >> synthetic_events But if there is a space, it returns an error. # echo "myevent u64 var ;" > synthetic_events sh: write error: Invalid argument This behavior is difficult for users to understand. Let's allow the last independent semicolon too. Link: http://lkml.kernel.org/r/153986835420.18251.2191216690677025744.stgit@devbox Cc: Shuah Khan Cc: Tom Zanussi Cc: stable@vger.kernel.org Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Fix synthetic event to accept unsigned modifier

2018-10-19T21:25:11Z

Fix synthetic event to accept unsigned modifier for its field type correctly. Currently, synthetic_events interface returns error for "unsigned" modifiers as below; # echo "myevent unsigned long var" >> synthetic_events sh: write error: Invalid argument This is because argv_split() breaks "unsigned long" into "unsigned" and "long", but parse_synth_field() doesn't expected it. With this fix, synthetic_events can handle the "unsigned long" correctly like as below; # echo "myevent unsigned long var" >> synthetic_events # cat synthetic_events myevent unsigned long var Link: http://lkml.kernel.org/r/153986832571.18251.8448135724590496531.stgit@devbox Cc: Shuah Khan Cc: Tom Zanussi Cc: stable@vger.kernel.org Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Add SPDX License format tags to tracing files

2018-08-16T23:08:06Z

Add the SPDX License header to ease license compliance management. Signed-off-by: Steven Rostedt (VMware)

tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()

2018-08-10T19:12:01Z

Now that some trace events can be protected by srcu_read_lock(tracepoint_srcu), we need to make sure all locations that depend on this are also protected. There were many places that did a synchronize_sched() thinking that it was enough to protect againts access to trace events. This use to be the case, but now that we use SRCU for _rcuidle() trace events, they may not be protected by synchronize_sched(), as they may be called in paths that RCU is not watching for preempt disable. Fixes: e6753f23d961d ("tracepoint: Make rcuidle tracepoint callers use SRCU") Signed-off-by: Steven Rostedt (VMware)

tracing: Avoid string overflow

2018-07-03T22:14:39Z

'err' is used as a NUL-terminated string, but using strncpy() with the length equal to the buffer size may result in lack of the termination: kernel/trace/trace_events_hist.c: In function 'hist_err_event': kernel/trace/trace_events_hist.c:396:3: error: 'strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation] strncpy(err, var, MAX_FILTER_STR_VAL); This changes it to use the safer strscpy() instead. Link: http://lkml.kernel.org/r/20180328140920.2842153-1-arnd@arndb.de Cc: stable@vger.kernel.org Fixes: f404da6e1d46 ("tracing: Add 'last error' error facility for hist triggers") Acked-by: Tom Zanussi Signed-off-by: Arnd Bergmann Signed-off-by: Steven Rostedt (VMware)

tracing: Allow histogram triggers to access ftrace internal events

2018-05-29T12:29:22Z

Now that trace_marker can have triggers, including a histogram triggers, the onmatch() and onmax() access the trace event. To do so, the search routine to find the event file needs to use the raw __find_event_file() that does not filter out ftrace events. Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware)

tracing: Add field modifier parsing hist error for hist triggers

2018-04-27T01:39:58Z

If the user specifies an invalid field modifier for a hist trigger, the current code correctly flags that as an error, but doesn't tell the user what happened. Fix this by invoking hist_err() with an appropriate message when invalid modifiers are specified. Before: # echo 'hist:keys=pid:ts0=common_timestamp.junkusecs' >> /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger -su: echo: write error: Invalid argument # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist After: # echo 'hist:keys=pid:ts0=common_timestamp.junkusecs' >> /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger -su: echo: write error: Invalid argument # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist ERROR: Invalid field modifier: junkusecs Last command: keys=pid:ts0=common_timestamp.junkusecs Link: http://lkml.kernel.org/r/b043c59fa79acd06a5f14a1d44dee9e5a3cd1248.1524790601.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Add field parsing hist error for hist triggers

2018-04-27T01:39:32Z

If the user specifies a nonexistent field for a hist trigger, the current code correctly flags that as an error, but doesn't tell the user what happened. Fix this by invoking hist_err() with an appropriate message when nonexistent fields are specified. Before: # echo 'hist:keys=pid:ts0=common_timestamp.usecs' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger -su: echo: write error: Invalid argument # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist After: # echo 'hist:keys=pid:ts0=common_timestamp.usecs' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger -su: echo: write error: Invalid argument # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist ERROR: Couldn't find field: pid Last command: keys=pid:ts0=common_timestamp.usecs Link: http://lkml.kernel.org/r/fdc8746969d16906120f162b99dd71c741e0b62c.1524790601.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Reported-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Restore proper field flag printing when displaying triggers

2018-04-27T01:38:43Z

The flag-printing code used when displaying hist triggers somehow got dropped during refactoring of the inter-event patchset. This restores it. Below are a couple examples - in the first case, .usecs wasn't being displayed properly for common_timestamps and the second illustrates the same for other flags such as .execname. Before: # echo 'hist:key=common_pid.execname:val=count:sort=count' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger hist:keys=common_pid:vals=hitcount,count:sort=count:size=2048 [active] # echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger hist:keys=pid:vals=hitcount:ts0=common_timestamp:sort=hitcount:size=2048:clock=global if comm=="cyclictest" [active] After: # echo 'hist:key=common_pid.execname:val=count:sort=count' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger hist:keys=common_pid.execname:vals=hitcount,count:sort=count:size=2048 [active] # echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger hist:keys=pid:vals=hitcount:ts0=common_timestamp.usecs:sort=hitcount:size=2048:clock=global if comm=="cyclictest" [active] Link: http://lkml.kernel.org/r/492bab42ff21806600af98a8ea901af10efbee0c.1524790601.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Uninitialized variable in create_tracing_map_fields()

2018-04-06T12:56:50Z

Smatch complains that idx can be used uninitialized when we check if (idx < 0). It has to be the first iteration through the loop and the HIST_FIELD_FL_STACKTRACE bit has to be clear and the HIST_FIELD_FL_VAR bit has to be set to reach the bug. Link: http://lkml.kernel.org/r/20180328114815.GC29050@mwanda Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers") Acked-by: Tom Zanussi Signed-off-by: Dan Carpenter Signed-off-by: Steven Rostedt (VMware)