linux-stable.git/kernel/trace, branch v6.1.9

tracing/osnoise: Use built-in RCU list checking

2023-02-01T07:34:46+00:00

[ Upstream commit 685b64e4d6da4be8b4595654a57db663b3d1dfc2 ]

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence false lockdep
warning when CONFIG_PROVE_RCU_LIST is enabled.

Execute as follow:

 [tracing]# echo osnoise > current_tracer
 [tracing]# echo 1 > tracing_on
 [tracing]# echo 0 > tracing_on

The trace_types_lock is held when osnoise_tracer_stop() or
timerlat_tracer_stop() are called in the non-RCU read side section.
So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep
warning.

Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@gmail.com

Cc: Masami Hiramatsu 
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Acked-by: Daniel Bristot de Oliveira 
Signed-off-by: Chuang Wang 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Sasha Levin

trace_events_hist: add check for return value of 'create_hist_field'

2023-02-01T07:34:37+00:00

commit 8b152e9150d07a885f95e1fd401fc81af202d9a4 upstream.

Function 'create_hist_field' is called recursively at
trace_events_hist.c:1954 and can return NULL-value that's why we have
to check it to avoid null pointer dereference.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Link: https://lkml.kernel.org/r/20230111120409.4111-1-n.petrova@fintech.ru

Cc: stable@vger.kernel.org
Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers")
Signed-off-by: Natalia Petrova 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing: Make sure trace_printk() can output as soon as it can be used

2023-02-01T07:34:37+00:00

commit 3bb06eb6e9acf7c4a3e1b5bc87aed398ff8e2253 upstream.

Currently trace_printk() can be used as soon as early_trace_init() is
called from start_kernel(). But if a crash happens, and
"ftrace_dump_on_oops" is set on the kernel command line, all you get will
be:

  [    0.456075]   -0         0dN.2. 347519us : Unknown type 6
  [    0.456075]   -0         0dN.2. 353141us : Unknown type 6
  [    0.456075]   -0         0dN.2. 358684us : Unknown type 6

This is because the trace_printk() event (type 6) hasn't been registered
yet. That gets done via an early_initcall(), which may be early, but not
early enough.

Instead of registering the trace_printk() event (and other ftrace events,
which are not trace events) via an early_initcall(), have them registered at
the same time that trace_printk() can be used. This way, if there is a
crash before early_initcall(), then the trace_printk()s will actually be
useful.

Link: https://lkml.kernel.org/r/20230104161412.019f6c55@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu 
Fixes: e725c731e3bb1 ("tracing: Split tracing initialization into two for early initialization")
Reported-by: "Joel Fernandes (Google)" 
Tested-by: Joel Fernandes (Google) 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

ftrace: Export ftrace_free_filter() to modules

2023-02-01T07:34:37+00:00

commit 8be9fbd5345da52f4a74f7f81d55ff9fa0a2958e upstream.

Setting filters on an ftrace ops results in some memory being allocated
for the filter hashes, which must be freed before the ops can be freed.
This can be done by removing every individual element of the hash by
calling ftrace_set_filter_ip() or ftrace_set_filter_ips() with `remove`
set, but this is somewhat error prone as it's easy to forget to remove
an element.

Make it easier to clean this up by exporting ftrace_free_filter(), which
can be used to clean up all of the filter hashes after an ftrace_ops has
been unregistered.

Using this, fix the ftrace-direct* samples to free hashes prior to being
unloaded. All other code either removes individual filters explicitly or
is built-in and already calls ftrace_free_filter().

Link: https://lkml.kernel.org/r/20230103124912.2948963-3-mark.rutland@arm.com

Cc: stable@vger.kernel.org
Cc: Florent Revest 
Cc: Masami Hiramatsu 
Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface")
Fixes: 5fae941b9a6f ("ftrace/samples: Add multi direct interface test module")
Reviewed-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google) 
Signed-off-by: Mark Rutland 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix infinite loop in tracing_read_pipe on overflowed print_trace_line

2023-01-07T10:11:49+00:00

commit c1ac03af6ed45d05786c219d102f37eb44880f28 upstream.

print_trace_line may overflow seq_file buffer. If the event is not
consumed, the while loop keeps peeking this event, causing a infinite loop.

Link: https://lkml.kernel.org/r/20221129113009.182425-1-yangjihong1@huawei.com

Cc: Masami Hiramatsu 
Cc: stable@vger.kernel.org
Fixes: 088b1e427dbba ("ftrace: pipe fixes")
Signed-off-by: Yang Jihong 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix issue of missing one synthetic field

2023-01-07T10:11:48+00:00

commit ff4837f7fe59ff018eca4705a70eca5e0b486b97 upstream.

The maximum number of synthetic fields supported is defined as
SYNTH_FIELDS_MAX which value currently is 64, but it actually fails
when try to generate a synthetic event with 64 fields by executing like:

  # echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\
   int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\
   int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\
   int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\
   int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\
   int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\
   int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\
   int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\
   int v63; int v64" >> /sys/kernel/tracing/synthetic_events

Correct the field counting to fix it.

Link: https://lore.kernel.org/linux-trace-kernel/20221207091557.3137904-1-zhengyejian1@huawei.com

Cc: 
Cc: 
Cc: stable@vger.kernel.org
Fixes: c9e759b1e845 ("tracing: Rework synthetic event command parsing")
Signed-off-by: Zheng Yejian 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing/probes: Handle system names with hyphens

2023-01-07T10:11:48+00:00

commit 575b76cb885532aae13a9d979fd476bb2b156cb9 upstream.

When creating probe names, a check is done to make sure it matches basic C
standard variable naming standards. Basically, starts with alphabetic or
underline, and then the rest of the characters have alpha-numeric or
underline in them.

But system names do not have any true naming conventions, as they are
created by the TRACE_SYSTEM macro and nothing tests to see what they are.
The "xhci-hcd" trace events has a '-' in the system name. When trying to
attach a eprobe to one of these trace points, it fails because the system
name does not follow the variable naming convention because of the
hyphen, and the eprobe checks fail on this.

Allow hyphens in the system name so that eprobes can attach to the
"xhci-hcd" trace events.

Link: https://lore.kernel.org/all/Y3eJ8GiGnEvVd8%2FN@macondo/
Link: https://lore.kernel.org/linux-trace-kernel/20221122122345.160f5077@gandalf.local.home

Cc: Masami Hiramatsu 
Cc: stable@vger.kernel.org
Fixes: 5b7a96220900e ("tracing/probe: Check event/group naming rule at parsing")
Reported-by: Rafael Mendonca 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing/hist: Fix wrong return value in parse_action_params()

2023-01-07T10:11:48+00:00

commit 2cc6a528882d0e0ccbc1bca5f95b8c963cedac54 upstream.

When number of synth fields is more than SYNTH_FIELDS_MAX,
parse_action_params() should return -EINVAL.

Link: https://lore.kernel.org/linux-trace-kernel/20221207034635.2253990-1-zhengyejian1@huawei.com

Cc: 
Cc: 
Cc: stable@vger.kernel.org
Fixes: c282a386a397 ("tracing: Add 'onmatch' hist trigger action support")
Signed-off-by: Zheng Yejian 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix complicated dependency of CONFIG_TRACER_MAX_TRACE

2023-01-07T10:11:48+00:00

commit e25e43a4e5d8cb2323553d8b6a7ba08d2ebab21f upstream.

Both CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER partially enables the
CONFIG_TRACER_MAX_TRACE code, but that is complicated and has
introduced a bug; It declares tracing_max_lat_fops data structure outside
of #ifdefs, but since it is defined only when CONFIG_TRACER_MAX_TRACE=y
or CONFIG_HWLAT_TRACER=y, if only CONFIG_OSNOISE_TRACER=y, that
declaration comes to a definition(!).

To fix this issue, and do not repeat the similar problem, makes
CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER enables the
CONFIG_TRACER_MAX_TRACE always. It has there benefits;
- Fix the tracing_max_lat_fops bug
- Simplify the #ifdefs
- CONFIG_TRACER_MAX_TRACE code is fully enabled, or not.

Link: https://lore.kernel.org/linux-trace-kernel/167033628155.4111793.12185405690820208159.stgit@devnote3

Fixes: 424b650f35c7 ("tracing: Fix missing osnoise tracer on max_latency")
Cc: Daniel Bristot de Oliveira 
Cc: stable@vger.kernel.org
Reported-by: David Howells 
Reported-by: kernel test robot 
Signed-off-by: Masami Hiramatsu (Google) 
Link: https://lore.kernel.org/all/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ (original thread and v1)
Link: https://lore.kernel.org/all/202212052253.VuhZ2ulJ-lkp@intel.com/T/#u (v1 error report)
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix race where eprobes can be called before the event

2023-01-07T10:11:48+00:00

commit d5f30a7da8ea8e6450250275cec5670cee3c4264 upstream.

The flag that tells the event to call its triggers after reading the event
is set for eprobes after the eprobe is enabled. This leads to a race where
the eprobe may be triggered at the beginning of the event where the record
information is NULL. The eprobe then dereferences the NULL record causing
a NULL kernel pointer bug.

Test for a NULL record to keep this from happening.

Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/
Link: https://lore.kernel.org/all/20221117214249.2addbe10@gandalf.local.home/

Cc: stable@vger.kernel.org
Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events")
Reported-by: Rafael Mendonca 
Signed-off-by: Steven Rostedt (Google) 
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Greg Kroah-Hartman