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Message-Id: <20180530180108.e3a7a37672e65d5ee685596f@kernel.org>
Date: Wed, 30 May 2018 18:01:08 +0900
From: Masami Hiramatsu <mhiramat@...nel.org>
To: naveen.n.rao@...ux.vnet.ibm.com
Cc: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...nel.org>, x86@...nel.org,
Ingo Molnar <mingo@...hat.com>,
"H . Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
Ananth N Mavinakayanahalli <ananth@...ux.vnet.ibm.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Steven Rostedt <rostedt@...dmis.org>,
Laura Abbott <labbott@...hat.com>, Josef Bacik <jbacik@...com>,
Alexei Starovoitov <ast@...nel.org>,
Ravi Bangoria <ravi.bangoria@...ux.vnet.ibm.com>,
Vineet Gupta <vgupta@...opsys.com>,
Russell King <linux@...linux.org.uk>,
Arnd Bergmann <arnd@...db.de>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Tony Luck <tony.luck@...el.com>,
Fenghua Yu <fenghua.yu@...el.com>,
Ralf Baechle <ralf@...ux-mips.org>,
James Hogan <jhogan@...nel.org>,
Martin Schwidefsky <schwidefsky@...ibm.com>,
Heiko Carstens <heiko.carstens@...ibm.com>,
Yoshinori Sato <ysato@...rs.sourceforge.jp>,
Rich Felker <dalias@...c.org>,
"David S . Miller" <davem@...emloft.net>,
linux-arch@...r.kernel.org
Subject: Re: [PATCH -tip v4 00/27] kprobes: Cleanup jprobe implementation
Hi Naveen,
Sorry, I might miss to add you on CC list. Could you test and review this on powerpc?
Thank you,
On Mon, 28 May 2018 15:59:09 +0900
Masami Hiramatsu <mhiramat@...nel.org> wrote:
> Hello,
>
> Since we decided to remove jprobe from kernel last year,
> its APIs are disabled and we worked on moving in-kernel
> jprobe users to kprobes or trace-events. And now no jprobe
> users are here anymore.
>
> This is the 4th version of the series for removing jprobe.
> Previous version is here:
>
> https://lkml.org/lkml/2018/5/16/1052
>
> Unlike previous versions, this version removes jprobe from
> all architectures, as Ingo asked me in the previous thread.
>
> I marked this as RFC again because it introduced changes for
> many arch. It should be reviewed by some arch which is not
> simply removing code (e.g. powerpc, arm).
>
> BTW, this series are based on -tip tree as same as its
> previous version, and I'm sure it can be applied to
> linus tree/linux-next too.
>
> Series structure
> =====
> Basically this series introduces 3 major changes;
>
> - Remove jprobe implementation ([2/27] - [12/27])
>
> - Remove break_handler() related code ([13/27] - [23/27])
> This should be done after (or with) removing jprobe
> because break_handler is only used by jprobe.
> (I'm not so sure, should I merge above patches into one
> arch-wide patch as next one does?)
>
> - Clean current_kprobe and enable preempt if pre_handler()
> returns !0 ([24/27] and [25/27]<- x86 specific update)
> This also depends on above patches because those
> current_kprobe and preemption are expected to be adjusted
> by jprobe implementation via break_handler.
>
> And some minor changes;
>
> - Document cleanup and update ([1/27], [26/27])
>
> And finally remove jprobe stub APIs and break_handler
> from kprobes.h ([27/27]). Of course this depends on
> above patches.
>
> Since removing jprobes and break_handler related code
> involve archtecture specific changes in some archs,
> I splitted it for each arch. But "clean current_kprobe and
> enable preempt if pre_handler() returns !0" patch modifies
> all architectures, since it changes expected kprobe
> handler behavior. I think this would be better done in
> one patch for consistency.
>
> Result
> =====
> I've tested it with kprobe sanity test on x86-64, and arm64
> but for other archs, I just did cross-build test.
>
> With this series, we finally cleanup all jprobe code
> and break_handler as below.
>
> $ git grep -wi break_handler | wc -l
> 0
> $ git grep -wi jprobe | wc -l
> 0
>
> Actually, there is one place where mentioning jprobe,
> Documentation/kprobes.txt explains jprobe is deprecated
> and how to migrate jprobe user to ftrace or kprobe.
> I didn't remove it because it might be useful for
> some users.
>
> Thank you,
>
> ---
>
> Masami Hiramatsu (27):
> Documentation/kprobes: Fix to remove remaining jprobe
> kprobes: Remove jprobe API implementation
> kprobes/x86: Remove jprobe implementation
> ARC: kprobes: Remove jprobe implementation
> ARM: kprobes: Remove jprobe arm implementation
> arm64: kprobes: Remove jprobe implementation
> powerpc/kprobes: Remove jprobe powerpc implementation
> ia64: kprobes: Remove jprobe implementation
> MIPS: kprobes: Remove jprobe implementation
> s390/kprobes: Remove jprobe implementation
> sh: kprobes: Remove jprobe implementation
> sparc64: kprobes: Remove jprobe implementation
> kprobes: Don't check the ->break_handler() in generic kprobes code
> kprobes/x86: Don't call ->break_handler() in x86 kprobes
> ARC: kprobes: Don't call the ->break_handler() in ARC kprobes code
> ARM: kprobes: Don't call the ->break_handler() in arm kprobes code
> arm64: kprobes: Don't call the ->break_handler() in arm kprobes code
> powerpc/kprobes: Don't call the ->break_handler() in arm kprobes code
> ia64: kprobes: Don't call the ->break_handler() in ia64 kprobes code
> MIPS: kprobes: Don't call the ->break_handler() in MIPS kprobes code
> s390/kprobes: Don't call the ->break_handler() in s390 kprobes code
> sh: kprobes: Don't call the ->break_handler() in SH kprobes code
> sparc64: kprobes: Don't call the ->break_handler() in sparc64 kprobes code
> bpf: error-inject: kprobes: Clear current_kprobe and enable preempt in kprobe
> x86: kprobes: Do not disable preempt on int3 path
> Documentation: kprobes: Add how to change the execution path
> kprobes: Remove jprobe stub API
>
>
> Documentation/kprobes.txt | 35 +++++-
> arch/arc/include/asm/kprobes.h | 2
> arch/arc/kernel/kprobes.c | 50 +--------
> arch/arm/include/asm/kprobes.h | 2
> arch/arm/include/asm/probes.h | 1
> arch/arm/probes/kprobes/core.c | 135 +-----------------------
> arch/arm64/include/asm/kprobes.h | 1
> arch/arm64/kernel/probes/kprobes.c | 86 +--------------
> arch/ia64/include/asm/kprobes.h | 2
> arch/ia64/include/uapi/asm/break.h | 1
> arch/ia64/kernel/Makefile | 2
> arch/ia64/kernel/jprobes.S | 90 ----------------
> arch/ia64/kernel/kprobes.c | 93 +----------------
> arch/mips/include/asm/kprobes.h | 13 --
> arch/mips/kernel/kprobes.c | 70 ++----------
> arch/powerpc/include/asm/kprobes.h | 12 --
> arch/powerpc/kernel/kprobes-ftrace.c | 31 +-----
> arch/powerpc/kernel/kprobes.c | 92 +++-------------
> arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 39 +------
> arch/s390/include/asm/kprobes.h | 2
> arch/s390/kernel/kprobes.c | 86 +--------------
> arch/sh/include/asm/kprobes.h | 4 -
> arch/sh/kernel/kprobes.c | 72 +------------
> arch/sparc/include/asm/kprobes.h | 1
> arch/sparc/kernel/kprobes.c | 65 +-----------
> arch/x86/include/asm/kprobes.h | 5 -
> arch/x86/kernel/kprobes/common.h | 10 --
> arch/x86/kernel/kprobes/core.c | 119 +--------------------
> arch/x86/kernel/kprobes/ftrace.c | 31 ++----
> arch/x86/kernel/kprobes/opt.c | 1
> include/linux/kprobes.h | 53 ---------
> kernel/fail_function.c | 3 -
> kernel/kprobes.c | 115 +-------------------
> kernel/test_kprobes.c | 94 -----------------
> kernel/trace/trace_kprobe.c | 11 +-
> lib/Kconfig.debug | 2
> 36 files changed, 125 insertions(+), 1306 deletions(-)
> delete mode 100644 arch/ia64/kernel/jprobes.S
>
> --
> Masami Hiramatsu (Linaro)
--
Masami Hiramatsu <mhiramat@...nel.org>
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