RE: [PATCH 02/13] module: add a module_loaded helper

[David Laight <David.Laight@ACULAB.COM>]

From: Christophe Leroy
> Sent: 21 January 2021 10:00
> 
> Le 21/01/2021 à 08:49, Christoph Hellwig a écrit :
> > Add a helper that takes modules_mutex and uses find_module to check if a
> > given module is loaded.  This provides a better abstraction for the two
> > callers, and allows to unexport modules_mutex and find_module.
> >
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> >   drivers/gpu/drm/drm_fb_helper.c |  7 +------
> >   include/linux/module.h          |  3 +++
> >   kernel/module.c                 | 14 ++++++++++++--
> >   kernel/trace/trace_kprobe.c     |  4 +---
> >   4 files changed, 17 insertions(+), 11 deletions(-)
> >
> 
> > diff --git a/include/linux/module.h b/include/linux/module.h
> > index 7a0bcb5b1ffccd..b4654f8a408134 100644
> > --- a/include/linux/module.h
> > +++ b/include/linux/module.h
> > @@ -589,6 +589,9 @@ static inline bool within_module(unsigned long addr, const struct module *mod)
> >   /* Search for module by name: must hold module_mutex. */
> >   struct module *find_module(const char *name);
> >
> > +/* Check if a module is loaded. */
> > +bool module_loaded(const char *name);
> 
> Maybe module_is_loaded() would be a better name.

I can't see the original patch.

What is the point of the function.
By the time it returns the information is stale - so mostly useless.

Surely you need to use try_module_get() instead?

	David

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