Re: [PATCH v2 0/4] arm64: kprobes: Update blacklist checking on arm64

From: Masami Hiramatsu
Date: Sat Jan 19 2019 - 08:31:33 EST


Hi Will,

On Wed, 16 Jan 2019 13:40:07 +0000
Will Deacon <will.deacon@xxxxxxx> wrote:

> Hi Masami,
>
> On Tue, Jan 15, 2019 at 03:23:39PM +0900, Masami Hiramatsu wrote:
> > Hello,
> >
> > Here is the v2 series of update of the kprobe blacklist
> > checking on arm64.
> >
> > I found that some blacklist checking code were mis-placed in
> > arch_prepare_kprobe() and arch_within_kprobe_blacklist().
> > Since the blacklist just filters by symbol, smaller than the
> > symbol, like extable must be checked in arch_prepare_kprobe().
> > Also, all function (symbol) level check must be done by blacklist.
> >
> > For arm64, it checks the extable entry address in blacklist
> > and exception/irqentry function in arch_prepare_kprobe().
> > And, RODATA check is unneeded since kernel/kprobes.c
> > already ensures the probe address is in kernel-text area.
> >
> > In v2, I updated [1/4]'s description and added James'
> > Reviewed-by. Also, in this version, I added a patch which
> > uses arch_populate_kprobe_blacklist() instead of
> > arch_within_kprobe_blacklist() so that user can see the full
> > list of blacklisted symbols under the debugfs.
>
> Assuming these are targetting the arm64 tree, are you intending to get them
> merged for 5.0?

No, I don't rush it, since these are not bugfix but just enhancements.
(User can see the blacklisted symbols precisely) If you think you are
easy to pick this to arm64/next, it is OK to me.

Thank you,

--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>