linux-kernel - Re: [PATCH] PM: sleep: Drop superfluous might

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAJZ5v0hbuQ8sRctAB7eC3JTr5TrDBnu5yjjG82HrSiJ23_99bQ@mail.gmail.com>
Date: Thu, 3 Jul 2025 16:35:55 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Zhongqiu Han <quic_zhonhan@...cinc.com>
Cc: rafael@...nel.org, len.brown@...el.com, pavel@...nel.org, 
	gregkh@...uxfoundation.org, dakr@...nel.org, linux-pm@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] PM: sleep: Drop superfluous might_sleep() calls

On Tue, Jun 17, 2025 at 10:47 AM Zhongqiu Han <quic_zhonhan@...cinc.com> wrote:
>
> Drop superfluous might_sleep() calls from dpm_resume(), dpm_complete(),
> and dpm_prepare(). These functions already invoke primitives that
> implicitly check for sleep in atomic context:
>
> - dpm_resume() and dpm_complete() invoke mutex_lock(), which internally
>   triggers might_sleep()
> - dpm_prepare() calls wait_for_device_probe(), which internally uses
>   flush_work(), and thus might_sleep()
>
> These annotations are unnecessary and can be dropped to reduce clutter.
>
> Signed-off-by: Zhongqiu Han <quic_zhonhan@...cinc.com>
> ---
>  drivers/base/power/main.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index eebe699fdf4f..0f40c00c1401 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -1095,7 +1095,6 @@ void dpm_resume(pm_message_t state)
>         ktime_t starttime = ktime_get();
>
>         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
> -       might_sleep();
>
>         pm_transition = state;
>         async_error = 0;
> @@ -1198,7 +1197,6 @@ void dpm_complete(pm_message_t state)
>         struct list_head list;
>
>         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
> -       might_sleep();
>
>         INIT_LIST_HEAD(&list);
>         mutex_lock(&dpm_list_mtx);
> @@ -2109,7 +2107,6 @@ int dpm_prepare(pm_message_t state)
>         int error = 0;
>
>         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
> -       might_sleep();
>
>         /*
>          * Give a chance for the known devices to complete their probes, before
> --

Applied as 6.17 material, thanks!