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* [RFC PATCH tip/master V3 0/8] kprobes/x86: Make kprobes instruction buffers read-only
@ 2017-03-29  4:55 Masami Hiramatsu
  2017-03-29  4:56 ` [RFC PATCH tip/master V3 1/8] kprobes/x86: Fix not to boost call far instruction Masami Hiramatsu
                   ` (8 more replies)
  0 siblings, 9 replies; 18+ messages in thread
From: Masami Hiramatsu @ 2017-03-29  4:55 UTC (permalink / raw)
  To: linux-kernel, Ingo Molnar
  Cc: Peter Zijlstra, Thomas Gleixner, H . Peter Anvin,
	Ananth N Mavinakayanahalli, Anil S Keshavamurthy,
	David S . Miller, Andrey Ryabinin, Ye Xiaolong, mhiramat

Hi,

This is the 3rd version of the series. I just updated 4/8 according
to Ingo's comment.

This series tries to make kprobes instruction buffers read-only
pages. Since those buffers are used for trampoline code, those
are a part of "text area" and it should be marked as ro for
avoiding unexpected modification. And this actually fix a warning
rodata sanity check reported by lkp-robot.

https://lkml.org/lkml/2017/2/27/161

This change requires changing the kprobe-booster at first
because it can modify the instruction buffer to add a jump while
resuming from single-stepping. Of course after we make the buffer
readonly, we may not be able to modify it while probing.

So, at first this series checks the current bootable instructions
and fixes a missed instruction (call far), modifies can_boost to
use x86 instruction decoder, and inserts "booster" jump while
preparing instruction buffer instead of resuming from single-stepping.
At last, it makes the buffers for kprobes and optprobe readonly.

This series also has some cleanup patches related to above 
changes.

Changes from V2:
 - [4/8]: Fix imbalanced curly braces and remove unneeded
   (void *) cast.

---

Masami Hiramatsu (8):
      kprobes/x86: Fix not to boost call far instruction
      kprobes/x86: Fix the description of __copy_instruction()
      kprobes/x86: Use instruction decoder for booster
      kprobes/x86: Do not modify singlestep buffer while resuming
      kprobes/x86: Make boostable flag boolean
      kprobes/x86: Set kprobes pages readonly
      kprobes/x86: Use probe_kernel_read instead of memcpy
      kprobes/x86: Consolidate insn decoder users for copying code


 arch/x86/include/asm/kprobes.h   |    7 +-
 arch/x86/kernel/kprobes/common.h |    4 +
 arch/x86/kernel/kprobes/core.c   |  149 +++++++++++++++++++-------------------
 arch/x86/kernel/kprobes/ftrace.c |    2 -
 arch/x86/kernel/kprobes/opt.c    |   13 +++
 5 files changed, 90 insertions(+), 85 deletions(-)

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>

^ permalink raw reply	[flat|nested] 18+ messages in thread

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Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-03-29  4:55 [RFC PATCH tip/master V3 0/8] kprobes/x86: Make kprobes instruction buffers read-only Masami Hiramatsu
2017-03-29  4:56 ` [RFC PATCH tip/master V3 1/8] kprobes/x86: Fix not to boost call far instruction Masami Hiramatsu
2017-04-12  7:32   ` [tip:perf/core] kprobes/x86: Fix kprobe-booster not to boost far call instructions tip-bot for Masami Hiramatsu
2017-03-29  4:58 ` [RFC PATCH tip/master V3 2/8] kprobes/x86: Fix the description of __copy_instruction() Masami Hiramatsu
2017-04-12  7:32   ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29  4:59 ` [RFC PATCH tip/master V3 3/8] kprobes/x86: Use instruction decoder for booster Masami Hiramatsu
2017-04-12  7:33   ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29  5:00 ` [RFC PATCH tip/master V3 4/8] kprobes/x86: Do not modify singlestep buffer while resuming Masami Hiramatsu
2017-04-12  7:33   ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29  5:01 ` [RFC PATCH tip/master V3 5/8] kprobes/x86: Make boostable flag boolean Masami Hiramatsu
2017-04-12  7:34   ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29  5:02 ` [RFC PATCH tip/master V3 6/8] kprobes/x86: Set kprobes pages readonly Masami Hiramatsu
2017-04-12  7:34   ` [tip:perf/core] kprobes/x86: Set kprobes pages read-only tip-bot for Masami Hiramatsu
2017-03-29  5:03 ` [RFC PATCH tip/master V3 7/8] kprobes/x86: Use probe_kernel_read instead of memcpy Masami Hiramatsu
2017-04-12  7:35   ` [tip:perf/core] kprobes/x86: Use probe_kernel_read() instead of memcpy() tip-bot for Masami Hiramatsu
2017-03-29  5:05 ` [RFC PATCH tip/master V3 8/8] kprobes/x86: Consolidate insn decoder users for copying code Masami Hiramatsu
2017-04-12  7:35   ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-04-11  5:44 ` [RFC PATCH tip/master V3 0/8] kprobes/x86: Make kprobes instruction buffers read-only Masami Hiramatsu

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