linux-toradex.git/kernel/trace/trace_boot.c, branch v5.10-rc3

tracing/boot: Add ftrace.instance.*.alloc_snapshot option

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

Add ftrace.instance.*.alloc_snapshot option.

This option has been described in Documentation/trace/boottime-trace.rst
but not implemented yet.

ftrace.[instance.INSTANCE.]alloc_snapshot
   Allocate snapshot buffer.

The difference from kernel.alloc_snapshot is that the kernel.alloc_snapshot
will allocate the buffer only for the main instance, but this can allocate
buffer for any new instances.

Link: https://lkml.kernel.org/r/160234368948.400560.15313384470765915015.stgit@devnote2

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

tracing/boot, kprobe, synth: Initialize boot-time tracing earlier

2020-09-22T01:06:04+00:00

Initialize boot-time tracing in core_initcall_sync instead of
fs_initcall, and initialize required tracers (kprobes and synth)
in core_initcall. This will allow the boot-time tracing to trace
__init code from the beginning of postcore_initcall stage.

Link: https://lkml.kernel.org/r/159974155727.478751.7486926132902849578.stgit@devnote2

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

tracing/boot: Add per-instance tracing_on option support

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

Add per-instance tracing_on option, which will be useful with
traceon/traceoff event trigger actions. For example, if we
disable tracing_on by default and set traceon and traceoff on
a pair of events, we can trace functions between the pair of
events.

Link: https://lkml.kernel.org/r/159972811538.428528.2561315102284268611.stgit@devnote2

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

tracing/boottime: Fix kprobe multiple events

2020-06-24T01:51:50+00:00

Fix boottime kprobe events to report and abort after each failure when
adding probes.

As an example, when we try to set multiprobe kprobe events in
bootconfig like this:

ftrace.event.kprobes.vfsevents {
        probes = "vfs_read $arg1 $arg2,,
                 !error! not reported;?", // leads to error
                 "vfs_write $arg1 $arg2"
}

This will not work as expected. After
commit da0f1f4167e3af69e ("tracing/boottime: Fix kprobe event API usage"),
the function trace_boot_add_kprobe_event will not produce any error
message when adding a probe fails at kprobe_event_gen_cmd_start.
Furthermore, we continue to add probes when kprobe_event_gen_cmd_end fails
(and kprobe_event_gen_cmd_start did not fail). In this case the function
even returns successfully when the last call to kprobe_event_gen_cmd_end
is successful.

The behaviour of reporting and aborting after failures is not
consistent.

The function trace_boot_add_kprobe_event now reports each failure and
stops adding probes immediately.

Link: https://lkml.kernel.org/r/20200618163301.25854-1-sascha.ortmann@stud.uni-hannover.de

Cc: stable@vger.kernel.org
Cc: linux-kernel@i4.cs.fau.de
Co-developed-by: Maximilian Werner 
Fixes: da0f1f4167e3 ("tracing/boottime: Fix kprobe event API usage")
Acked-by: Masami Hiramatsu 
Signed-off-by: Maximilian Werner 
Signed-off-by: Sascha Ortmann 
Signed-off-by: Steven Rostedt (VMware)

tracing/boot: Fix config dependency for synthedic event

2020-06-24T01:51:22+00:00

Since commit 726721a51838 ("tracing: Move synthetic events to
a separate file") decoupled synthetic event from histogram,
boot-time tracing also has to check CONFIG_SYNTH_EVENT instead
of CONFIG_HIST_TRIGGERS.

Link: http://lkml.kernel.org/r/159262475441.185015.5300725180746017555.stgit@devnote2

Fixes: 726721a51838 ("tracing: Move synthetic events to a separate file")
Reviewed-by: Tom Zanussi 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/boottime: Fix kprobe event API usage

2020-05-06T13:04:11+00:00

Fix boottime kprobe events to use API correctly for
multiple events.

For example, when we set a multiprobe kprobe events in
bootconfig like below,

  ftrace.event.kprobes.myevent {
  	probes = "vfs_read $arg1 $arg2", "vfs_write $arg1 $arg2"
  }

This cause an error;

  trace_boot: Failed to add probe: p:kprobes/myevent (null)  vfs_read $arg1 $arg2  vfs_write $arg1 $arg2

This shows the 1st argument becomes NULL and multiprobes
are merged to 1 probe.

Link: http://lkml.kernel.org/r/158779375766.6082.201939936008972838.stgit@devnote2

Cc: Ingo Molnar 
Cc: stable@vger.kernel.org
Fixes: 29a154810546 ("tracing: Change trace_boot to use kprobe_event interface")
Reviewed-by: Tom Zanussi 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing: Change trace_boot to use synth_event interface

2020-01-31T17:59:26+00:00

Have trace_boot_add_synth_event() use the synth_event interface.

Also, rename synth_event_run_cmd() to synth_event_run_command() now
that trace_boot's version is gone.

Link: http://lkml.kernel.org/r/94f1fa0e31846d0bddca916b8663404b20559e34.1580323897.git.zanussi@kernel.org

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

tracing: Change trace_boot to use kprobe_event interface

2020-01-30T14:46:28+00:00

Have trace_boot_add_kprobe_event() use the kprobe_event interface.

Also, rename kprobe_event_run_cmd() to kprobe_event_run_command() now
that trace_boot's version is gone.

Link: http://lkml.kernel.org/r/af5429d11291ab1e9a85a0ff944af3b2bcf193c7.1580323897.git.zanussi@kernel.org

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

tracing/boot: Move external function declarations to kernel/trace/trace.h

2020-01-29T13:49:04+00:00

Move external function declarations into kernel/trace/trace.h
from trace_boot.c for tracing subsystem internal use.

Link: http://lkml.kernel.org/r/158029060405.12381.11944554430359702545.stgit@devnote2

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

tracing/boot: Include required headers and sort it alphabetically

2020-01-29T13:48:44+00:00

Include some required (but currently indirectly included)
headers and sort it alphabetically.

Link: http://lkml.kernel.org/r/158029059514.12381.6597832266860248781.stgit@devnote2

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