Commit 4e965200 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: control: Annotate snd_kcontrol with __counted_by() 

struct snd_kcontrol contains a flex array of snd_kcontrol_volatile
objects at its end, and the array size is stored in count field.
This can be annotated gracefully with __counted_by() for catching
possible array overflows.

One additional change is the order of the count field initialization;
The assignment of the count field is moved before assignment of vd[]
elements for avoiding false-positive warnings from compilers.

Link: https://patch.msgid.link/20240726152840.8629-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 3c0e1ed9

include/sound/control.h

+1 −1
Original line number Diff line number Diff line
@@ -81,7 +81,7 @@ struct snd_kcontrol { 
	unsigned long private_value;

	void *private_data;

	void (*private_free)(struct snd_kcontrol *kcontrol);

	struct snd_kcontrol_volatile vd[];	/* volatile data */

	struct snd_kcontrol_volatile vd[] __counted_by(count);	/* volatile data */

};



#define snd_kcontrol(n) list_entry(n, struct snd_kcontrol, list)

sound/core/control.c

+1 −1
Original line number Diff line number Diff line
@@ -237,11 +237,11 @@ static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count, 
	if (!*kctl)

		return -ENOMEM;



	(*kctl)->count = count;

	for (idx = 0; idx < count; idx++) {

		(*kctl)->vd[idx].access = access;

		(*kctl)->vd[idx].owner = file;

	}

	(*kctl)->count = count;



	return 0;

}