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Date: Thu, 4 Apr 2024 18:11:09 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
	Jiri Olsa <olsajiri@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>, linux-kernel@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org,
	Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Borislav Petkov (AMD)" <bp@alien8.de>, x86@kernel.org,
	linux-api@vger.kernel.org
Subject: Re: [PATCHv2 1/3] uprobe: Add uretprobe syscall to speed up return
 probe
Message-ID: <20240404161108.GG7153@redhat.com>
References: <20240402093302.2416467-1-jolsa@kernel.org>
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On 04/05, Masami Hiramatsu wrote:
>
> Can we make this syscall and uprobe behavior clearer? As you said, if
> the application use sigreturn or longjump, it may skip returns and
> shadow stack entries are left in the kernel. In such cases, can uretprobe
> detect it properly, or just crash the process (or process runs wrongly)?

Please see the comment in handle_trampoline(), it tries to detect this case.
This patch should not make any difference.

Oleg.