From: Masami Hiramatsu <mhiramat@kernel.org>
To: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
Jiri Kosina <jkosina@suse.cz>,
Josh Poimboeuf <jpoimboe@redhat.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Chris von Recklinghausen <crecklin@redhat.com>,
Jason Baron <jbaron@akamai.com>, Scott Wood <swood@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Clark Williams <williams@redhat.com>,
x86@kernel.org
Subject: Re: [PATCH V4 8/9] jump_label: Batch updates if arch supports it
Date: Wed, 6 Feb 2019 15:34:18 +0900 [thread overview]
Message-ID: <20190206153418.722cc7f4a83d0e48c8dca552@kernel.org> (raw)
In-Reply-To: <a36bfdbc63c5848adfaa1a466a90b62391fd2289.1549308412.git.bristot@redhat.com>
On Mon, 4 Feb 2019 20:59:01 +0100
Daniel Bristot de Oliveira <bristot@redhat.com> wrote:
> --- a/kernel/jump_label.c
> +++ b/kernel/jump_label.c
> @@ -407,6 +407,7 @@ bool jump_label_can_update_check(struct jump_entry *entry, bool init)
> return 0;
> }
>
> +#ifndef HAVE_JUMP_LABEL_BATCH
> static void __jump_label_update(struct static_key *key,
> struct jump_entry *entry,
> struct jump_entry *stop,
> @@ -419,6 +420,34 @@ static void __jump_label_update(struct static_key *key,
> }
> }
> }
> +#else
> +static void __jump_label_update(struct static_key *key,
> + struct jump_entry *entry,
> + struct jump_entry *stop,
> + bool init)
> +{
> + for_each_label_entry(key, entry, stop) {
> +
> + if (!jump_label_can_update_check(entry, init))
> + continue;
> +
> + if (arch_jump_label_transform_queue(entry,
> + jump_label_type(entry)))
> + continue;
> +
> + /*
> + * Queue's overflow: Apply the current queue, and then
> + * queue again. If it stills not possible to queue, BUG!
> + */
> + arch_jump_label_transform_apply();
> + if (!arch_jump_label_transform_queue(entry,
> + jump_label_type(entry))) {
> + BUG();
Please do not relay on BUG(), since in both case (applied or not),
jump_label is not critical for normal operation. I think you should use
WARN_ONCE() here and lock the jump_label so that root user can report it
to us :)
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2019-02-06 6:34 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-04 19:58 [PATCH V4 0/9] x86/jump_label: Bound IPIs sent when updating a static key Daniel Bristot de Oliveira
2019-02-04 19:58 ` [PATCH V4 1/9] jump_label: Add for_each_label_entry helper Daniel Bristot de Oliveira
2019-02-04 19:58 ` [PATCH V4 2/9] jump_label: Add the jump_label_can_update_check() helper Daniel Bristot de Oliveira
2019-02-05 7:22 ` Borislav Petkov
2019-02-05 13:50 ` Daniel Bristot de Oliveira
2019-02-05 21:13 ` Borislav Petkov
2019-02-07 13:21 ` Daniel Bristot de Oliveira
2019-02-07 14:08 ` Borislav Petkov
2019-02-07 17:00 ` Daniel Bristot de Oliveira
2019-02-07 17:08 ` Borislav Petkov
2019-02-04 19:58 ` [PATCH V4 3/9] x86/jump_label: Move checking code away from __jump_label_transform() Daniel Bristot de Oliveira
2019-02-05 7:33 ` Borislav Petkov
2019-02-05 15:22 ` Daniel Bristot de Oliveira
2019-02-15 10:05 ` Daniel Bristot de Oliveira
2019-02-04 19:58 ` [PATCH V4 4/9] x86/jump_label: Add __jump_label_set_jump_code() helper Daniel Bristot de Oliveira
2019-02-04 19:58 ` [PATCH V4 5/9] x86/alternative: Split text_poke_bp() into tree steps Daniel Bristot de Oliveira
2019-02-06 19:07 ` Borislav Petkov
2019-02-08 0:11 ` Steven Rostedt
2019-02-08 0:15 ` Steven Rostedt
2019-02-15 12:47 ` Daniel Bristot de Oliveira
2019-02-21 15:26 ` Steven Rostedt
2019-02-04 19:58 ` [PATCH V4 6/9] jump_label: Sort entries of the same key by the code Daniel Bristot de Oliveira
2019-02-04 19:59 ` [PATCH V4 7/9] x86/alternative: Batch of patch operations Daniel Bristot de Oliveira
2019-02-14 12:53 ` Borislav Petkov
2019-02-14 14:06 ` Steven Rostedt
2019-02-14 14:30 ` Borislav Petkov
2019-02-14 14:40 ` Steven Rostedt
2019-02-14 14:54 ` Borislav Petkov
2019-02-15 16:00 ` Daniel Bristot de Oliveira
2019-02-15 17:20 ` Steven Rostedt
2019-02-04 19:59 ` [PATCH V4 8/9] jump_label: Batch updates if arch supports it Daniel Bristot de Oliveira
2019-02-06 6:34 ` Masami Hiramatsu [this message]
2019-02-06 15:59 ` Daniel Bristot de Oliveira
2019-02-14 13:33 ` Borislav Petkov
2019-02-04 19:59 ` [PATCH V4 9/9] x86/jump_label: Batch jump label updates Daniel Bristot de Oliveira
2019-02-06 6:29 ` Masami Hiramatsu
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