From: "Nicholas Piggin" <npiggin@gmail.com>
To: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
"Michael Ellerman" <mpe@ellerman.id.au>
Cc: linux-arch@vger.kernel.org, Jordan Niethe <jniethe5@gmail.com>,
linuxppc-dev@lists.ozlabs.org,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [PATCH 0/5] powerpc/kprobes: preempt related changes and cleanups
Date: Mon, 07 Nov 2022 21:24:42 +1000 [thread overview]
Message-ID: <CO60Y4MBO8W7.1OSJEIWNIBAHH@bobo> (raw)
In-Reply-To: <cover.1666262278.git.naveen.n.rao@linux.vnet.ibm.com>
+linux-arch
FYI most preempt_enable_no_resched() calls outside of core scheduler
code come from kprobes copy-and-paste, and can possibly be fixed in
similar ways as this series. It's a bit of a footgun API that should
be banished from outside kernel/sched/, at least without an explicit
comment for each case that explains the need and how the missed
resched is resolved or not applicable.
Thanks,
Nick
On Fri Oct 21, 2022 at 3:28 AM AEST, Naveen N. Rao wrote:
> This series attempts to address some of the concerns raised in
> https://github.com/linuxppc/issues/issues/440
>
> The last two patches are minor cleanups in related kprobes code.
>
> - Naveen
>
>
> Naveen N. Rao (5):
> powerpc/kprobes: Remove preempt disable around call to get_kprobe() in
> arch_prepare_kprobe()
> powerpc/kprobes: Have optimized_callback() use preempt_enable()
> powerpc/kprobes: Use preempt_enable() rather than the no_resched
> variant
> powerpc/kprobes: Setup consistent pt_regs across kprobes, optprobes
> and KPROBES_ON_FTRACE
> powerpc/kprobes: Remove unnecessary headers from kprobes
>
> arch/powerpc/kernel/kprobes-ftrace.c | 4 ----
> arch/powerpc/kernel/kprobes.c | 16 ++++++----------
> arch/powerpc/kernel/optprobes.c | 2 +-
> arch/powerpc/kernel/optprobes_head.S | 5 +----
> arch/powerpc/kernel/trace/ftrace_mprofile.S | 6 ++++++
> 5 files changed, 14 insertions(+), 19 deletions(-)
>
>
> base-commit: 7dc2a00fdd44a4d0c3bac9fd10558b3933586a0c
> --
> 2.38.0
next prev parent reply other threads:[~2022-11-07 11:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-20 17:28 [PATCH 0/5] powerpc/kprobes: preempt related changes and cleanups Naveen N. Rao
2022-10-20 17:28 ` [PATCH 1/5] powerpc/kprobes: Remove preempt disable around call to get_kprobe() in arch_prepare_kprobe() Naveen N. Rao
2022-11-07 10:14 ` Nicholas Piggin
2022-11-08 10:33 ` Naveen N. Rao
2022-10-20 17:28 ` [PATCH 2/5] powerpc/kprobes: Have optimized_callback() use preempt_enable() Naveen N. Rao
2022-11-07 10:18 ` Nicholas Piggin
2022-10-20 17:28 ` [PATCH 3/5] powerpc/kprobes: Use preempt_enable() rather than the no_resched variant Naveen N. Rao
2022-11-07 10:29 ` Nicholas Piggin
2022-10-20 17:29 ` [PATCH 4/5] powerpc/kprobes: Setup consistent pt_regs across kprobes, optprobes and KPROBES_ON_FTRACE Naveen N. Rao
2022-11-07 11:15 ` Nicholas Piggin
2022-11-08 10:52 ` Naveen N. Rao
2022-10-20 17:29 ` [PATCH 5/5] powerpc/kprobes: Remove unnecessary headers from kprobes Naveen N. Rao
2022-11-02 8:36 ` Christophe Leroy
2022-11-08 10:06 ` Naveen N. Rao
2022-11-07 11:24 ` Nicholas Piggin [this message]
2022-11-30 9:24 ` (subset) [PATCH 0/5] powerpc/kprobes: preempt related changes and cleanups Michael Ellerman
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