linux-toradex.git/kernel/trace/trace_probe.h, branch v5.12-rc5

tracing/dynevent: Delegate parsing to create function

2021-02-09T17:52:15+00:00

Delegate command parsing to each create function so that the
command syntax can be customized.

This requires changes to the kprobe/uprobe/synthetic event handling,
which are also included here.

Link: https://lkml.kernel.org/r/e488726f49cbdbc01568618f8680584306c4c79f.1612208610.git.zanussi@kernel.org

Signed-off-by: Masami Hiramatsu 
[ zanussi@kernel.org: added synthetic event modifications ]
Signed-off-by: Tom Zanussi 
Signed-off-by: Steven Rostedt (VMware)

tracing: Move is_good_name() from trace_probe.h to trace.h

2020-10-15T16:01:13+00:00

is_good_name() is useful for other trace infrastructure, such as
synthetic events, so make it available via trace.h.

Link: https://lkml.kernel.org/r/cc6d6a2d7da6957fcbe1e2922e76d18d2bb459b4.1602598160.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu 
Tested-by: Masami Hiramatsu 
Signed-off-by: Tom Zanussi 
Signed-off-by: Steven Rostedt (VMware)

tracing/kprobes: Support perf-style return probe

2020-09-22T01:06:03+00:00

Support perf-style return probe ("SYMBOL%return") for kprobe events.
This will allow boot-time tracing user to define a return probe event.

Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Replace zero-length array with flexible-array

2020-06-16T04:08:32+00:00

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva

tracing/uprobe: Fix to make trace_uprobe_filter alignment safe

2020-01-22T12:09:20+00:00

Commit 99c9a923e97a ("tracing/uprobe: Fix double perf_event
linking on multiprobe uprobe") moved trace_uprobe_filter on
trace_probe_event. However, since it introduced a flexible
data structure with char array and type casting, the
alignment of trace_uprobe_filter can be broken.

This changes the type of the array to trace_uprobe_filter
data strucure to fix it.

Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net
Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2

Fixes: 99c9a923e97a ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe")
Suggested-by: Peter Zijlstra 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/uprobe: Fix double perf_event linking on multiprobe uprobe

2020-01-14T20:57:59+00:00

Fix double perf_event linking to trace_uprobe_filter on
multiple uprobe event by moving trace_uprobe_filter under
trace_probe_event.

In uprobe perf event, trace_uprobe_filter data structure is
managing target mm filters (in perf_event) related to each
uprobe event.

Since commit 60d53e2c3b75 ("tracing/probe: Split trace_event
related data from trace_probe") left the trace_uprobe_filter
data structure in trace_uprobe, if a trace_probe_event has
multiple trace_uprobe (multi-probe event), a perf_event is
added to different trace_uprobe_filter on each trace_uprobe.
This leads a linked list corruption.

To fix this issue, move trace_uprobe_filter to trace_probe_event
and link it once on each event instead of each probe.

Link: http://lkml.kernel.org/r/157862073931.1800.3800576241181489174.stgit@devnote2

Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: "Naveen N . Rao" 
Cc: Anil S Keshavamurthy 
Cc: "David S . Miller" 
Cc: Namhyung Kim 
Cc: =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?b?w7hyZ2Vuc2Vu?= 
Cc: Jean-Tsung Hsiao 
Cc: Jesper Dangaard Brouer 
Cc: stable@vger.kernel.org
Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe")
Link: https://lkml.kernel.org/r/20200108171611.GA8472@kernel.org
Reported-by: Arnaldo Carvalho de Melo 
Tested-by: Arnaldo Carvalho de Melo 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Reject exactly same probe event

2019-09-19T15:09:16+00:00

Reject exactly same probe events as existing probes.

Multiprobe allows user to define multiple probes on same
event. If user appends a probe which exactly same definition
(same probe address and same arguments) on existing event,
the event will record same probe information twice.
That can be confusing users, so reject it.

Link: http://lkml.kernel.org/r/156879694602.31056.5533024778165036763.stgit@devnote2

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Add immediate string parameter support

2019-08-31T16:19:39+00:00

Add immediate string parameter (\"string") support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching a string from
memory.

This feature looks odd, but imagine that you put a probe
on a code to trace some string data. If the code is
compiled into 2 instructions and 1 instruction has a
string on memory but other has no string since it is
optimized out. In that case, you can not fold those into
one event, even if ftrace supported multiple probes on
one event. With this feature, you can set a dummy string
like foo=\"(optimized)":string instead of something
like foo=+0(+0(%bp)):string.

Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.stgit@devnote2

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Add immediate parameter support

2019-08-31T16:19:39+00:00

Add immediate value parameter (\1234) support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching from memory
or register.

This feature looks odd, but imagine when you put a probe
on a code to trace some data. If the code is compiled into
2 instructions and 1 instruction has a value but other has
nothing since it is optimized out.
In that case, you can not fold those into one event, even
if ftrace supported multiple probes on one event.
With this feature, you can set a dummy value like
foo=\deadbeef instead of something like foo=%di.

Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/kprobe: Add per-probe delete from event

2019-08-31T16:19:38+00:00

Allow user to delete a probe from event. This is done by head
match. For example, if we have 2 probes on an event

$ cat kprobe_events
p:kprobes/testprobe _do_fork r1=%ax r2=%dx
p:kprobes/testprobe idle_fork r1=%ax r2=%cx

Then you can remove one of them by passing the head of definition
which identify the probe.

$ echo "-:kprobes/testprobe idle_fork" >> kprobe_events

Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)