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From:   Dongliang Mu <mudongliangabcd@gmail.com>
Date:   Mon, 18 Oct 2021 17:17:41 +0800
Message-ID: <CAD-N9QV69ttLMn07tAiK7iz9ZWaREv51RYwWVP55ChPiVjgHGQ@mail.gmail.com>
Subject: Re: Any tracing mechanism can track the executed instructions of a
 user process in the kernel?
To:     FMDF <fmdefrancesco@gmail.com>
Cc:     kernelnewbies <kernelnewbies@kernelnewbies.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Pavel Skripkin <paskripkin@gmail.com>,
        Brendan Gregg <brendan.d.gregg@gmail.com>
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+Brendan Gregg

On Mon, Oct 18, 2021 at 4:41 PM Dongliang Mu <mudongliangabcd@gmail.com> wr=
ote:
>
> On Mon, Oct 18, 2021 at 4:07 PM FMDF <fmdefrancesco@gmail.com> wrote:
> >
> > On Mon, 18 Oct 2021, 04:46 Dongliang Mu, <mudongliangabcd@gmail.com> wr=
ote:
> >>
> >> Hi all,
> >>
> >> I am writing to kindly ask one question: is there any tracing
> >> mechanism in Linux kernel that can trace all the executed instructions
> >> of a user process? If this user process is run on different
> >> processors, traces of this process on different processors should be
> >> also recorded.
> >
> >
> > You've not explained in detail what is the purpose of the tracing that =
you want to do. Missing this information I can only provide you a list of l=
inks to various tools and methods. Take a look by yourself and try to figur=
e out what is better suited for your needs...
>
> I want to log all the executed instructions of a user process (e.g.,
> poc.c in syzkaller) in the kernel mode and then would like to leverage
> backward analysis to capture the root cause of kernel panic/crash.
>
> Therefore, I need the instruction-level tracing mechanisms or tools.
>
> >
> > https://lwn.net/Kernel/Index/#Development_tools-Kernel_tracing
> > trace-cmd: https://trace-cmd.org
>
> Ftrace is working at the function level. Therefore, ftrace and tracers
> based on ftrace are not suitable for my scenario.
>
> > perf ftrace: <Linux source>/tools/perf/Documentation/perf-trace.txt
> > perf-tools: https://github.com/brendangregg/perf-tools
>
> I am not familiar with the perf tool and cannot verify if it works for
> my scenario.
>
> >
> > In particular, the "function_graph" tracer of ftrace seems to be suited=
 for your purposes:
> >
> > https://man7.org/linux/man-pages/man1/trace-cmd.1.html
> > https://man7.org/linux/man-pages/man1/trace-cmd-record.1.html
> > https://man7.org/linux/man-pages/man1/trace-cmd-report.1.html
> >
> > Obviously, gdb (and friends) is still invaluable (but it may be difficu=
lt to use, depending on your knowledge and experience, so use it if you rea=
lly know that  you need it):
> >
> > https://www.kernel.org/doc/html/latest/dev-tools/gdb-kernel-debugging.h=
tml
> > https://www.kernel.org/doc/html/latest/dev-tools/kgdb.html
> >
> > Regards,
> >
> > Fabio M. De Francesco
> >
> >>
> >> Any comment is welcome.
> >>
> >> --
> >> My best regards to you.
> >>
> >>      No System Is Safe!
> >>      Dongliang Mu
> >>
> >> _______________________________________________
> >> Kernelnewbies mailing list
> >> Kernelnewbies@kernelnewbies.org
> >> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies