linux-kernel - Re: [PATCH] base: fix a missing check of clk

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, 1 Jan 2019 21:13:01 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Pavel Machek <pavel@....cz>
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>, kjlu@....edu,
        pakki001@....edu, "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <len.brown@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] base: fix a missing check of clk_prepare

On Mon, Dec 31, 2018 at 6:25 PM Pavel Machek <pavel@....cz> wrote:
>
> On Wed 2018-12-26 10:37:54, Rafael J. Wysocki wrote:
> > On Wed, Dec 26, 2018 at 3:47 AM Kangjie Lu <kjlu@....edu> wrote:
> > >
> > > clk_prepare() could fail, so let's check its status, and if it fails,
> > > issue an error message.
> > >
> > > Signed-off-by: Kangjie Lu <kjlu@....edu>
> > > ---
> > >  drivers/base/power/clock_ops.c | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
> > > index 5a42ae4078c2..cb6144fb24e2 100644
> > > --- a/drivers/base/power/clock_ops.c
> > > +++ b/drivers/base/power/clock_ops.c
> > > @@ -65,7 +65,9 @@ static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
> > >         if (IS_ERR(ce->clk)) {
> > >                 ce->status = PCE_STATUS_ERROR;
> > >         } else {
> > > -               clk_prepare(ce->clk);
> > > +               if (clk_prepare(ce->clk))
> > > +                       dev_err(dev, "clk_prepare failed.\n");
> >
> > I'm not sure that this is useful.  The code continues regardless of
> > the error anyway and it should at least set ce->status to
> > PCE_STATUS_ERROR in the failing case.
>
> Maybe this is not complete fix, but dev_err() is preferable to silent
> failure.

Preferable to you I suppose?