Messages in this thread | | | Subject | Re: [PATCH] clk: Emit a stern warning with writable debugfs enabled | From | Stephen Boyd <> | Date | Fri, 10 Dec 2021 15:12:07 -0800 |
| |
Quoting Geert Uytterhoeven (2021-12-09 23:57:25) > Hi Stephen, > > On Fri, Dec 10, 2021 at 2:42 AM Stephen Boyd <sboyd@kernel.org> wrote: > > We don't want vendors to be enabling this part of the clk code and > > shipping it to customers. Exposing the ability to change clk frequencies > > and parents via debugfs is potentially damaging to the system if folks > > don't know what they're doing. Emit a strong warning so that the message > > is clear: don't enable this outside of development systems. > > > > Fixes: 37215da5553e ("clk: Add support for setting clk_rate via debugfs") > > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > > Signed-off-by: Stephen Boyd <sboyd@kernel.org> > > Thanks for your patch! > > > --- a/drivers/clk/clk.c > > +++ b/drivers/clk/clk.c > > @@ -3383,6 +3383,24 @@ static int __init clk_debug_init(void) > > { > > struct clk_core *core; > > > > +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS > > + pr_warn("\n"); > > + pr_warn("********************************************************************\n"); > > + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); > > + pr_warn("** **\n"); > > + pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n"); > > + pr_warn("** **\n"); > > + pr_warn("** This means that this kernel is built to expose clk operations **\n"); > > + pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n"); > > + pr_warn("** to userspace, which may compromise security on your system. **\n"); > > + pr_warn("** **\n"); > > + pr_warn("** If you see this message and you are not debugging the **\n"); > > + pr_warn("** kernel, report this immediately to your vendor! **\n"); > > + pr_warn("** **\n"); > > + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); > > + pr_warn("********************************************************************\n"); > > So how many variants of such blocks do we have now in the kernel? >
Quite a few!
| |