[PATCH -tip v4 00/27] kprobes: Cleanup jprobe implementation
From: Masami Hiramatsu
Date: Mon May 28 2018 - 02:59:45 EST
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)