linux-stable.git/kernel/trace/trace_eprobe.c, branch v5.15.208

tracing/eprobe: Fix to release eprobe when failed to add dyn_event

2024-12-14T18:51:44+00:00

[ Upstream commit 494b332064c0ce2f7392fa92632bc50191c1b517 ]

Fix eprobe event to unregister event call and release eprobe when it fails
to add dynamic event correctly.

Link: https://lore.kernel.org/all/173289886698.73724.1959899350183686006.stgit@devnote2/

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Sasha Levin

kernel/trace: Fix cleanup logic of enable_trace_eprobe

2023-07-23T11:47:43+00:00

[ Upstream commit cf0a624dc706c306294c14e6b3e7694702f25191 ]

The enable_trace_eprobe() function enables all event probes, attached
to given trace probe. If an error occurs in enabling one of the event
probes, all others should be roll backed. There is a bug in that roll
back logic - instead of all event probes, only the failed one is
disabled.

Link: https://lore.kernel.org/all/20230703042853.1427493-1-tz.stoyanov@gmail.com/

Reported-by: Dan Carpenter 
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Tzvetomir Stoyanov (VMware) 
Acked-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google) 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Sasha Levin

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

2023-01-12T10:58:54+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

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

2022-11-26T08:24:43+00:00

commit 94eedf3dded5fb472ce97bfaf3ac1c6c29c35d26 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/linux-trace-kernel/20221117214249.2addbe10@gandalf.local.home

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

tracing: Move duplicate code of trace_kprobe/eprobe.c into header

2022-10-26T10:34:31+00:00

commit f1d3cbfaafc10464550c6d3a125f4fc802bbaed5 upstream.

The functions:

  fetch_store_strlen_user()
  fetch_store_strlen()
  fetch_store_string_user()
  fetch_store_string()

are identical in both trace_kprobe.c and trace_eprobe.c. Move them into
a new header file trace_probe_kernel.h to share it. This code will later
be used by the synthetic events as well.

Marked for stable as a fix for a crash in synthetic events requires it.

Link: https://lkml.kernel.org/r/20221012104534.467668078@goodmis.org

Cc: stable@vger.kernel.org
Cc: Andrew Morton 
Cc: Tom Zanussi 
Acked-by: Masami Hiramatsu (Google) 
Reviewed-by: Tom Zanussi 
Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing/eprobes: Fix reading of string fields

2022-08-25T09:40:28+00:00

commit f04dec93466a0481763f3b56cdadf8076e28bfbf upstream.

Currently when an event probe (eprobe) hooks to a string field, it does
not display it as a string, but instead as a number. This makes the field
rather useless. Handle the different kinds of strings, dynamic, static,
relational/dynamic etc.

Now when a string field is used, the ":string" type can be used to display
it:

  echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events

Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar 
Cc: Andrew Morton 
Cc: Tzvetomir Stoyanov 
Cc: Tom Zanussi 
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing/eprobes: Have event probes be consistent with kprobes and uprobes

2022-08-25T09:39:58+00:00

commit 6a832ec3d680b3a4f4fad5752672827d71bae501 upstream.

Currently, if a symbol "@" is attempted to be used with an event probe
(eprobes), it will cause a NULL pointer dereference crash.

Both kprobes and uprobes can reference data other than the main registers.
Such as immediate address, symbols and the current task name. Have eprobes
do the same thing.

For "comm", if "comm" is used and the event being attached to does not
have the "comm" field, then make it the "$comm" that kprobes has. This is
consistent to the way histograms and filters work.

Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar 
Cc: Andrew Morton 
Cc: Masami Hiramatsu 
Cc: Tzvetomir Stoyanov 
Cc: Tom Zanussi 
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix misspelling of "missing"

2021-10-29T13:54:14+00:00

My snake instinct was on and I wrote "misssing" instead of "missing".

Signed-off-by: Steven Rostedt (VMware)

tracing: Do not warn when connecting eprobe to non existing event

2021-10-28T01:47:55+00:00

When the syscall trace points are not configured in, the kselftests for
ftrace will try to attach an event probe (eprobe) to one of the system
call trace points. This triggered a WARNING, because the failure only
expects to see memory issues. But this is not the only failure. The user
may attempt to attach to a non existent event, and the kernel must not
warn about it.

Link: https://lkml.kernel.org/r/20211027120854.0680aa0f@gandalf.local.home

Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (VMware)

tracing: Fix event probe removal from dynamic events

2021-10-13T23:26:57+00:00

When an event probe is to be removed via the API that created it via the
dynamic events, an -ENOENT error is returned.

This is because the removal of the event probe does not expect to see the
event system and name that the event probe is attached to, even though
that's part of the API to create it. As the removal of probes is to use
the same API as they are created.

In fact, the removal is not consistent with the kprobes and uprobes
removal. Fix that by allowing various ways to remove the eprobe.

The eprobe is created with:

 e:[GROUP/]NAME SYSTEM/EVENT [OPTIONS]

Have it get removed by echoing in the following into dynamic_events:

 # Remove all eprobes with NAME
 echo '-:NAME' >> dynamic_events

 # Remove a specific eprobe
 echo '-:GROUP/NAME' >> dynamic_events
 echo '-:GROUP/NAME SYSTEM/EVENT' >> dynamic_events
 echo '-:NAME SYSTEM/EVENT' >> dynamic_events
 echo '-:GROUP/NAME SYSTEM/EVENT OPTIONS' >> dynamic_events
 echo '-:NAME SYSTEM/EVENT OPTIONS' >> dynamic_events

Link: https://lkml.kernel.org/r/20211012081925.0e19cc4f@gandalf.local.home
Link: https://lkml.kernel.org/r/20211013205533.630722129@goodmis.org

Suggested-by: Masami Hiramatsu 
Acked-by: Masami Hiramatsu 
Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (VMware)