linux/kernel/trace/trace_fprobe.c, branch v6.14

tracing: tprobe-events: Fix leakage of module refcount

2025-03-14T23:37:47Z

When enabling the tracepoint at loading module, the target module refcount is incremented by find_tracepoint_in_module(). But it is unnecessary because the module is not unloaded while processing module loading callbacks. Moreover, the refcount is not decremented in that function. To be clear the module refcount handling, move the try_module_get() callsite to trace_fprobe_create_internal(), where it is actually required. Link: https://lore.kernel.org/all/174182761071.83274.18334217580449925882.stgit@devnote2/ Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") Signed-off-by: Masami Hiramatsu (Google) Cc: stable@vger.kernel.org

tracing: tprobe-events: Fix to clean up tprobe correctly when module unload

2025-03-14T23:37:12Z

When unloading module, the tprobe events are not correctly cleaned up. Thus it becomes `fprobe-event` and never be enabled again even if loading the same module again. For example; # cd /sys/kernel/tracing # modprobe trace_events_sample # echo 't:my_tprobe foo_bar' >> dynamic_events # cat dynamic_events t:tracepoints/my_tprobe foo_bar # rmmod trace_events_sample # cat dynamic_events f:tracepoints/my_tprobe foo_bar As you can see, the second time my_tprobe starts with 'f' instead of 't'. This unregisters the fprobe and tracepoint callback when module is unloaded but marks the fprobe-event is tprobe-event. Link: https://lore.kernel.org/all/174158724946.189309.15826571379395619524.stgit@mhiramat.tok.corp.google.com/ Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") Signed-off-by: Masami Hiramatsu (Google)

tracing: fprobe-events: Log error for exceeding the number of entry args

2025-02-27T00:11:51Z

Add error message when the number of entry argument exceeds the maximum size of entry data. This is currently checked when registering fprobe, but in this case no error message is shown in the error_log file. Link: https://lore.kernel.org/all/174055074269.4079315.17809232650360988538.stgit@mhiramat.tok.corp.google.com/ Fixes: 25f00e40ce79 ("tracing/probes: Support $argN in return probe (kprobe and fprobe)") Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google)

tracing: tprobe-events: Reject invalid tracepoint name

2025-02-27T00:10:58Z

Commit 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") allows user to set a tprobe on non-exist tracepoint but it does not check the tracepoint name is acceptable. So it leads tprobe has a wrong character for events (e.g. with subsystem prefix). In this case, the event is not shown in the events directory. Reject such invalid tracepoint name. The tracepoint name must consist of alphabet or digit or '_'. Link: https://lore.kernel.org/all/174055073461.4079315.15875502830565214255.stgit@mhiramat.tok.corp.google.com/ Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Cc: stable@vger.kernel.org

tracing: tprobe-events: Fix a memory leak when tprobe with $retval

2025-02-27T00:10:21Z

Fix a memory leak when a tprobe is defined with $retval. This combination is not allowed, but the parse_symbol_and_return() does not free the *symbol which should not be used if it returns the error. Thus, it leaks the *symbol memory in that error path. Link: https://lore.kernel.org/all/174055072650.4079315.3063014346697447838.stgit@mhiramat.tok.corp.google.com/ Fixes: ce51e6153f77 ("tracing: fprobe-event: Fix to check tracepoint event and return") Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Cc: stable@vger.kernel.org

tracing: Adopt __free() and guard() for trace_fprobe.c

2025-01-17T02:27:07Z

Adopt __free() and guard() for trace_fprobe.c to remove gotos. Link: https://lore.kernel.org/173708043449.319651.12242878905778792182.stgit@mhiramat.roam.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

tracing/fprobe: Remove nr_maxactive from fprobe

2024-12-26T15:50:05Z

Remove depercated fprobe::nr_maxactive. This involves fprobe events to rejects the maxactive number. Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173519007257.391279.946804046982289337.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

2024-12-26T15:50:04Z

Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_FTRACE_REGS_HAVING_PT_REGS, fprobe events will not be able to be used from perf. Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173518999352.391279.13332699755290175168.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe exit handler

2024-12-26T15:50:03Z

Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which means the ftrace_regs is including the pt_regs so that ftrace_regs can provide pt_regs without memory allocation. Fprobe introduces a new dependency with that. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Cc: Huacai Chen Cc: Alexei Starovoitov Cc: Florent Revest Cc: bpf Cc: Alan Maguire Cc: Heiko Carstens Cc: WANG Xuerui Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Song Liu Cc: Jiri Olsa Cc: KP Singh Cc: Matt Bobrowski Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Eduard Zingerman Cc: Yonghong Song Cc: John Fastabend Cc: Stanislav Fomichev Cc: Hao Luo Cc: Andrew Morton Link: https://lore.kernel.org/173518995092.391279.6765116450352977627.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe entry handler

2024-12-26T15:50:03Z

This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe on arm64. Cc: Alexei Starovoitov Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173518994037.391279.2786805566359674586.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest Signed-off-by: Steven Rostedt (Google)