From: Steven Rostedt <rostedt@goodmis.org>
To: Jiri Olsa <olsajiri@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@kernel.org>,
Menglong Dong <menglong8.dong@gmail.com>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
kees@kernel.org, samitolvanen@google.com, rppt@kernel.org,
luto@kernel.org, ast@kernel.org, andrii@kernel.org,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH] tracing: fgraph: Protect return handler from recursion loop
Date: Mon, 22 Sep 2025 10:42:28 -0400 [thread overview]
Message-ID: <20250922104228.4993227e@batman.local.home> (raw)
In-Reply-To: <aNFRRa3m6Qm8zzQu@krava>
On Mon, 22 Sep 2025 15:38:13 +0200
Jiri Olsa <olsajiri@gmail.com> wrote:
> > I found ftrace_test_recursion_trylock() allows one nest level, can you
> > make sure it is OK?
>
> hum, I recall being surprised by that already in the past,
> I thought we fixed that somehow, will check later today
It still does allow one level of recursion, because there's still
locations that can trace in interrupt context before the preempt count
is updated to the new context.
I looked at fixing these, but IIRC, there's several locations in
assembly that do this and it started getting messy. I guess I can try
to fix this again.
-- Steve
next prev parent reply other threads:[~2025-09-22 14:42 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-18 12:09 [PATCH] x86/ibt: make is_endbr() notrace Menglong Dong
2025-09-18 13:05 ` Peter Zijlstra
2025-09-18 13:32 ` Menglong Dong
2025-09-18 16:02 ` Alexei Starovoitov
2025-09-18 16:59 ` Peter Zijlstra
2025-09-18 17:53 ` Alexei Starovoitov
2025-09-19 1:13 ` Menglong Dong
2025-09-22 6:52 ` Peter Zijlstra
2025-09-22 7:13 ` menglong.dong
2025-09-22 7:19 ` Peter Zijlstra
2025-09-22 7:21 ` Menglong Dong
2025-09-22 6:36 ` Peter Zijlstra
2025-09-18 16:56 ` Peter Zijlstra
2025-09-19 12:35 ` Masami Hiramatsu
2025-09-19 8:52 ` Masami Hiramatsu
2025-09-19 8:58 ` Menglong Dong
2025-09-19 12:32 ` Masami Hiramatsu
2025-09-19 11:57 ` [PATCH] tracing: fgraph: Protect return handler from recursion loop Masami Hiramatsu (Google)
2025-09-19 15:27 ` Steven Rostedt
2025-09-20 7:45 ` Jiri Olsa
2025-09-22 6:16 ` Masami Hiramatsu
2025-09-22 13:38 ` Jiri Olsa
2025-09-22 14:42 ` Steven Rostedt [this message]
2025-09-22 19:45 ` Jiri Olsa
2025-09-21 4:05 ` Masami Hiramatsu
2025-09-21 22:52 ` Steven Rostedt
2025-09-24 22:58 ` Masami Hiramatsu
2025-09-20 13:39 ` Menglong Dong
2025-09-21 4:06 ` Masami Hiramatsu
2025-09-21 23:00 ` Steven Rostedt
2025-09-24 22:59 ` Masami Hiramatsu
2025-09-22 5:19 ` Masami Hiramatsu
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