From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Masami Hiramatsu <mhiramat@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Will Deacon <will@kernel.org>, Kees Cook <keescook@chromium.org>,
Arnd Bergmann <arnd@arndb.de>, Alexandre Ghiti <alex@ghiti.fr>,
Masahiro Yamada <masahiroy@kernel.org>,
Sami Tolvanen <samitolvanen@google.com>,
Peter Collingbourne <pcc@google.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Stephen Boyd <sboyd@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Mike Rapoport <rppt@linux.ibm.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Jiri Olsa <jolsa@redhat.com>
Subject: Re: [PATCH RFC] kprobes: Remove MODULES dependency
Date: Fri, 10 Jul 2020 13:36:38 +0300 [thread overview]
Message-ID: <20200710103638.GA2614@linux.intel.com> (raw)
In-Reply-To: <20200710090344.GX4800@hirez.programming.kicks-ass.net>
On Fri, Jul 10, 2020 at 11:03:44AM +0200, Peter Zijlstra wrote:
> On Fri, Jul 10, 2020 at 02:45:19AM +0300, Jarkko Sakkinen wrote:
> > Remove MODULES dependency and migrate from module_alloc to vmalloc().
> > According to Andi, the history with this dependency is that kprobes
> > originally required custom LKM's, which does not hold today anymore.
> >
> > Right now one has to compile LKM support only to enable kprobes. With
> > this change applied, it is somewhat easier to create custom test
> > kernel's with a proper debugging capabilities, thus making Linux more
> > developer friendly.
> >
> > Cc: Andi Kleen <ak@linux.intel.com>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>
> NAK
>
> this patch is horrific, it sprinkles a metric ton of #ifdef and silently
> disables a lot of kprobe features (like all the opt stuff).
Perfectly nderstandable. I just drafted something quick andy dirty
together for idea's sake (and put RFC tag to state that).
The application where I use this chhange, is when I refactor large patch
set that I'm working on (namely SGX patch set in my case). I just want
squeece all the extra out from the kernel build and still have means for
instrumentation. A static kernel is very convenient for this kind of
purpose, as with EFI stub and statically linked user space you can have
a single test binary.
> How about unconditionally providing module_alloc() instead?
I believe so, yes.
Just so that I know (and learn), what did exactly disable optprobes?
Not too familiar with this part of the kernel - that's why I'm asking.
Does the module_alloc to vmalloc change disable it?
/Jarkko
next prev parent reply other threads:[~2020-07-10 10:37 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 23:45 [PATCH RFC] kprobes: Remove MODULES dependency Jarkko Sakkinen
2020-07-10 9:03 ` Peter Zijlstra
2020-07-10 10:36 ` Jarkko Sakkinen [this message]
2020-07-10 10:49 ` Peter Zijlstra
2020-07-13 5:05 ` Jarkko Sakkinen
2020-07-13 10:17 ` Peter Zijlstra
2020-07-14 11:52 ` Masami Hiramatsu
2020-07-10 10:32 ` Masami Hiramatsu
2020-07-10 11:32 ` Peter Zijlstra
2020-07-10 13:04 ` Christoph Hellwig
2020-07-13 5:52 ` Jarkko Sakkinen
2020-07-10 13:18 ` Masami Hiramatsu
2020-07-10 13:22 ` Steven Rostedt
2020-07-13 5:55 ` Jarkko Sakkinen
2020-07-13 5:49 ` Jarkko Sakkinen
2020-07-14 11:45 ` Masami Hiramatsu
2020-07-10 15:51 ` Kees Cook
2020-07-13 5:56 ` Jarkko Sakkinen
2020-07-13 5:39 ` Jarkko Sakkinen
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