Re: [PATCH v5 00/21] kprobes: Unify kretprobe trampoline handlers and make kretprobe lockless

From: Masami Hiramatsu
Date: Tue Sep 01 2020 - 20:37:49 EST


On Tue, 1 Sep 2020 21:08:08 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Sat, Aug 29, 2020 at 09:59:49PM +0900, Masami Hiramatsu wrote:
> > Masami Hiramatsu (16):
> > kprobes: Add generic kretprobe trampoline handler
> > x86/kprobes: Use generic kretprobe trampoline handler
> > arm: kprobes: Use generic kretprobe trampoline handler
> > arm64: kprobes: Use generic kretprobe trampoline handler
> > arc: kprobes: Use generic kretprobe trampoline handler
> > csky: kprobes: Use generic kretprobe trampoline handler
> > ia64: kprobes: Use generic kretprobe trampoline handler
> > mips: kprobes: Use generic kretprobe trampoline handler
> > parisc: kprobes: Use generic kretprobe trampoline handler
> > powerpc: kprobes: Use generic kretprobe trampoline handler
> > s390: kprobes: Use generic kretprobe trampoline handler
> > sh: kprobes: Use generic kretprobe trampoline handler
> > sparc: kprobes: Use generic kretprobe trampoline handler
> > kprobes: Remove NMI context check
> > kprobes: Free kretprobe_instance with rcu callback
> > kprobes: Make local used functions static
> >
> > Peter Zijlstra (5):
> > llist: Add nonatomic __llist_add() and __llist_dell_all()
> > kprobes: Remove kretprobe hash
> > asm-generic/atomic: Add try_cmpxchg() fallbacks
> > freelist: Lock less freelist
> > kprobes: Replace rp->free_instance with freelist
>
> This looks good to me, do you want me to merge them through -tip? If so,
> do we want to try and get them in this release still?

Yes, thanks. For the kretprobe missing issue, we will need the first half
(up to "kprobes: Remove NMI context check"), so we can split the series
if someone think the lockless is still immature.

>
> Ingo, opinions? This basically fixes a regression cauesd by
>
> 0d00449c7a28 ("x86: Replace ist_enter() with nmi_enter()")
>

Oops, I missed Ingo in CC.

Thank you,

--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>