Re: [PATCH -tip 0/2] x86: Prohibit kprobes on XEN_EMULATE_PREFIX

Peter Zijlstra
2019-09-04T12:02:50Z

On Wed, Sep 04, 2019 at 08:45:47PM +0900, Masami Hiramatsu wrote:
> Hi,
>
> These patches allow x86 instruction decoder to decode
> xen-cpuid which has XEN_EMULATE_PREFIX, and prohibit
> kprobes to probe on it.
>
> Josh reported that the objtool can not decode such special
> prefixed instructions, and I found that we also have to
> prohibit kprobes to probe on such instruction.
>
> This series can be applied on -tip master branch which
> has merged Josh's objtool/perf sharing common x86 insn
> decoder series.
>
>
> Thank you,
>
> ---
>
> Masami Hiramatsu (2):
> x86: xen: insn: Decode XEN_EMULATE_PREFIX correctly
> x86: kprobes: Prohibit probing on instruction which has Xen prefix
>
>
> arch/x86/include/asm/insn.h | 2 +
> arch/x86/include/asm/xen/interface.h | 7 ++++-
> arch/x86/include/asm/xen/prefix.h | 10 +++++++
> arch/x86/kernel/kprobes/core.c | 4 +++
> arch/x86/lib/insn.c | 43 +++++++++++++++++++++++++++++++
> tools/arch/x86/include/asm/insn.h | 2 +
> tools/arch/x86/include/asm/xen/prefix.h | 10 +++++++
> tools/arch/x86/lib/insn.c | 43 +++++++++++++++++++++++++++++++
> tools/objtool/sync-check.sh | 3 +-
> 9 files changed, 121 insertions(+), 3 deletions(-)
> create mode 100644 arch/x86/include/asm/xen/prefix.h
> create mode 100644 tools/arch/x86/include/asm/xen/prefix.h

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>