Re: [PATCH v3 1/2] module: pull out add_taint_module() to be public

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Sep 04, 2026 at 11:25:01AM +0200, Petr Pavlu wrote:
> On 9/4/26 7:10 AM, Greg Kroah-Hartman wrote:
> > Other kernel code might want to call add_taint_module() so pull it out
> > and make it global.  If modules are not enabled, this defaults to a call
> > to add_taint(), so all is fine.
> > 
> > Reviewed-by: Johan Hovold <johan@kernel.org>
> > Tested-by: Johan Hovold <johan@kernel.org>
> > Reviewed-by: Bradley Morgan <brads@mainlining.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> >  include/linux/module.h | 10 ++++++++++
> >  kernel/module/main.c   | 16 +++++++++++++---
> >  2 files changed, 23 insertions(+), 3 deletions(-)
> > 
> > diff --git a/include/linux/module.h b/include/linux/module.h
> > index 96cc98568eea..f6f90cd88f15 100644
> > --- a/include/linux/module.h
> > +++ b/include/linux/module.h
> > @@ -29,6 +29,7 @@
> >  #include <linux/srcu.h>
> >  #include <linux/static_call_types.h>
> >  #include <linux/dynamic_debug.h>
> > +#include <linux/panic.h>
> 
> Note that I'm working on cleaning up linux/module.h to reduce its
> preprocessed size. The main motivation is to shorten the compilation
> time of all the small *.mod.c files. Since linux/module.h already
> includes linux/panic.h indirectly, adding this include explicitly seems
> fine to me for now. In the future, I think we should introduce something
> like kernel/module/stubs.c where the CONFIG_MODULES=n variants of
> add_taint_module() and other similar functions can live without bloating
> linux/module.h.
> 
> >  
> >  #include <linux/percpu.h>
> >  #include <asm/module.h>
> > @@ -770,6 +771,9 @@ static inline bool is_livepatch_module(struct module *mod)
> >  
> >  void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data);
> >  
> > +void add_taint_module(struct module *mod, unsigned flag,
> > +		      enum lockdep_ok lockdep_ok);
> > +
> >  #else /* !CONFIG_MODULES... */
> >  
> >  static inline struct module *__module_address(unsigned long addr)
> > @@ -877,6 +881,12 @@ static inline bool module_is_coming(struct module *mod)
> >  static inline void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data)
> >  {
> >  }
> > +
> > +static inline void add_taint_module(struct module *mod, unsigned flag,
> > +				    enum lockdep_ok lockdep_ok)
> > +{
> > +	add_taint(flag, lockdep_ok);
> > +}
> >  #endif /* CONFIG_MODULES */
> >  
> >  #ifdef CONFIG_SYSFS
> > diff --git a/kernel/module/main.c b/kernel/module/main.c
> > index d0e1e0bd2ad0..444d990c9983 100644
> > --- a/kernel/module/main.c
> > +++ b/kernel/module/main.c
> > @@ -191,11 +191,21 @@ static inline int strong_try_module_get(struct module *mod)
> >  		return -ENOENT;
> >  }
> >  
> > -static inline void add_taint_module(struct module *mod, unsigned flag,
> > -				    enum lockdep_ok lockdep_ok)
> > +/**
> > + * add_taint_module: add a taint flag if not already set for a specific module
> > + * @mod: pointer to the module that caused the problem
> > + * @flag: one of the TAINT_* constants.
> > + * @lockdep_ok: whether lock debugging is still OK.
> > + *
> > + * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
> > + * some noteworthy-but-not-corrupting cases, it can be set to true.
> 
> Nit: The final paragraph is mostly copied from the description of
> add_taint() but I don't think it is quite right. The parameter name
> should be lockdep_ok, not lockdebug_ok and the values are
> LOCKDEP_STILL_OK / LOCKDEP_NOW_UNRELIABLE, not true / false.
> 
> I suggest updating this part for both add_taint() and add_taint_module()
> to something like:
> 
>  * Use @lockdep_ok = LOCKDEP_NOW_UNRELIABLE if something serious has gone wrong.
>  * For noteworthy but non-corrupting cases, use LOCKDEP_STILL_OK instead.

How about I add another patch to the series that fixes up the
documentation for both functions?  They both should be fixed up and I
might as well get them in sync properly.

> > + */
> > +void add_taint_module(struct module *mod, unsigned flag,
> > +		      enum lockdep_ok lockdep_ok)
> >  {
> >  	add_taint(flag, lockdep_ok);
> > -	set_bit(flag, &mod->taints);
> > +	if (mod)
> > +		set_bit(flag, &mod->taints);
> >  }
> >  
> >  /*
> > 
> 
> Otherwise, this looks ok to me. Feel free to add:
> 
> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>

Great, will do, and I'll do a v4 early next week with the documentation
fixes.

thanks,

greg k-h