linux-kernel - Re: [PATCH] PM: domains: not update genpd status when power on fail

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

Date:   Tue, 6 Jul 2021 11:44:32 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     "Peng Fan (OSS)" <peng.fan@....nxp.com>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>, Pavel Machek <pavel@....cz>,
        Len Brown <len.brown@...el.com>,
        Linux PM <linux-pm@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Peng Fan <peng.fan@....com>
Subject: Re: [PATCH] PM: domains: not update genpd status when power on fail

On Tue, 6 Jul 2021 at 11:31, <peng.fan@....nxp.com> wrote:
>
> From: Peng Fan <peng.fan@....com>
>
> When _genpd_power_on fail, the generic power domain status
> should not be changed to GENPD_STATE_ON.
>
> Signed-off-by: Peng Fan <peng.fan@....com>
> ---
>  drivers/base/power/domain.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index ab0b740cc0f1..754a5d384479 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1101,6 +1101,7 @@ static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
>                                 unsigned int depth)
>  {
>         struct gpd_link *link;
> +       int ret;
>
>         if (genpd_status_on(genpd))
>                 return;
> @@ -1117,8 +1118,9 @@ static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
>                         genpd_unlock(link->parent);
>         }
>
> -       _genpd_power_on(genpd, false);
> -       genpd->status = GENPD_STATE_ON;
> +       ret = _genpd_power_on(genpd, false);
> +       if (!ret)

To support this error path, a lot more code needs to be added. Just
have a look at the callers of genpd_sync_power_on() and compare it
with genpd_power_on().

In my opinion, supporting this error path isn't really worth it, at
least until someone comes with a valid use case. Do you have one - or
did you send the $subject patch based solely on code inspection?

> +               genpd->status = GENPD_STATE_ON;
>  }
>
>  /**
> --
> 2.30.0
>

Kind regards
Uffe