Re: [PATCH 3/3] Add marker_query service

* Mathieu Desnoyers ([email protected]) wrote:
> Will apply, but I wonder why we start "instance" at 1 instead of 0... ?
> 

Nevermind... it starts at 0.. I should fix my brain ;)

> * Jan Kiszka ([email protected]) wrote:
> > Introduce marker_query(name, instance) to obtain a reference to a
> > marker's __mark_marker_data structure. This information can be used to
> > search for markers of a specific name and check the returned format
> > string for consistency in more flexible ways or defer the check. So far
> > consistency checks are done via a full string match on marker_set_probe
> > invocation, now we can also apply checksum tests without having to know
> > the string in advance in the context of marker_set_probe.
> > 
> > 
> > Signed-off-by: Jan Kiszka <[email protected]>
> > 
> > ---
> >  include/linux/marker.h |    1 +
> >  kernel/module.c        |   47 +++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 48 insertions(+)
> > 
> > Index: linux-2.6.21.1/kernel/module.c
> > ===================================================================
> > --- linux-2.6.21.1.orig/kernel/module.c
> > +++ linux-2.6.21.1/kernel/module.c
> > @@ -448,6 +448,26 @@ static int marker_list_probe_range(marke
> >  	return found;
> >  }
> >  
> > +/* Looks up a marker by its name and instance number within the specificed
> > + * range and returns the associated data structure. */
> > +const struct __mark_marker_data *marker_query_range(const char *name,
> > +	int instance,
> > +	const struct __mark_marker *begin,
> > +	const struct __mark_marker *end)
> > +{
> > +	const struct __mark_marker *iter;
> > +	int found = 0;
> > +
> > +	for (iter = begin; iter < end; iter++) {
> > +		if (strcmp(name, iter->mdata->name) != 0)
> > +			continue;
> > +
> > +		if (found++ == instance)
> > +			return iter->mdata;
> > +	}
> > +	return NULL;
> > +}
> > +
> >  /* Calls _marker_set_probe_range for the core markers and modules markers.
> >   * Marker enabling/disabling use the modlist_lock to synchronise. */
> >  int _marker_set_probe(int flags, const char *name, const char *format,
> > @@ -522,6 +542,33 @@ int marker_list_probe(marker_probe_func 
> >  	return found;
> >  }
> >  EXPORT_SYMBOL_GPL(marker_list_probe);
> > +
> > +/* Looks up a marker by its name and instance number and returns the
> > + * associated data structure. */
> > +const struct __mark_marker_data *marker_query(const char *name, int instance)
> > +{
> > +	struct module *mod;
> > +	const struct __mark_marker_data *mdata;
> > +
> > +	mutex_lock(&module_mutex);
> > +	/* Core kernel markers */
> > +	mdata = marker_query_range(name, instance,
> > +			__start___markers, __stop___markers);
> > +	if (!mdata) {
> > +		/* Markers in modules. */
> > +		list_for_each_entry(mod, &modules, list)
> > +			if (!mod->taints) {
> > +				mdata = marker_query_range(name, instance,
> > +					mod->markers,
> > +					mod->markers+mod->num_markers);
> > +				if (mdata)
> > +					break;
> > +			}
> > +	}
> > +	mutex_unlock(&module_mutex);
> > +	return mdata;
> > +}
> > +EXPORT_SYMBOL_GPL(marker_query);
> >  #endif
> >  
> >  #ifdef CONFIG_SMP
> > Index: linux-2.6.21.1/include/linux/marker.h
> > ===================================================================
> > --- linux-2.6.21.1.orig/include/linux/marker.h
> > +++ linux-2.6.21.1/include/linux/marker.h
> > @@ -116,6 +116,7 @@ extern int _marker_set_probe(int flags, 
> >  
> >  extern int marker_remove_probe(const char *name);
> >  extern int marker_list_probe(marker_probe_func *probe);
> > +const struct __mark_marker_data *marker_query(const char *name, int instance);
> >  
> >  #endif /* __KERNEL__ */
> >  #endif
> > 
> 
> 
> 
> > _______________________________________________
> > Ltt-dev mailing list
> > [email protected]
> > http://listserv.shafik.org/mailman/listinfo/ltt-dev
> 
> 
> -- 
> Mathieu Desnoyers
> Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68



> _______________________________________________
> Ltt-dev mailing list
> [email protected]
> http://listserv.shafik.org/mailman/listinfo/ltt-dev


-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

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