Re: [PATCH 1/2] tracing: Prevent unloadable modules from usingtrace_bprintk()

From: Steven Rostedt
Date: Wed Oct 20 2010 - 23:48:03 EST


On Thu, 2010-10-21 at 05:42 +0200, Frederic Weisbecker wrote:

> > +/*
> > + * Module code must not use trace_bprintk, because if it is unloaded
> > + * then we leave a pointer back to the module code inside
> > + * the ring buffer, and then reading the ring buffer may cause a bug.
> > + *
> > + * We do allow for modules to use it if the kernel does not allow
> > + * unloading of modules, and MODVERSIONS is set (to make sure kernel
> > + * and module are the same). If you load modules without MODVERSIONS
> > + * set, then you deserve what you get.
> > + */
> > +#if defined(MODULE) && \
>
>
>
> Did you mean CONFIG_MODULE may be?

Nope, then the a kernel that allows modules wont use it. I do mean
"MODULE", as in defined by the Makefile:

KBUILD_AFLAGS_MODULE := -DMODULE
KBUILD_CFLAGS_MODULE := -DMODULE

-- Steve


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