On Tue, 29 Oct 2024 13:11:32 +0100, Amadeusz Sławiński wrote: > > On 10/29/2024 11:30 AM, Takashi Iwai wrote: > > On Tue, 29 Oct 2024 10:50:21 +0100, > > Amadeusz Sławiński wrote: > >> > >> On 10/28/2024 11:50 PM, Aleksei Vetrov wrote: > >>> The widgets array in the snd_soc_dapm_widget_list has a __counted_by > >>> attribute attached to it, which points to the num_widgets variable. This > >>> attribute is used in bounds checking, and if it is not set before the > >>> array is filled, then the bounds sanitizer will issue a warning or a > >>> kernel panic if CONFIG_UBSAN_TRAP is set. > >>> > >>> This patch sets the size of the widgets list calculated with > >>> list_for_each as the initial value for num_widgets as it is used for > >>> allocating memory for the array. It is updated with the actual number of > >>> added elements after the array is filled. > >>> > >>> Signed-off-by: Aleksei Vetrov <[email protected]> > >>> --- > >>> sound/soc/soc-dapm.c | 2 ++ > >>> 1 file changed, 2 insertions(+) > >>> > >>> diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c > >>> index > >>> c34934c31ffec3970b34b24dcaa0826dfb7d8e86..99521c784a9b16a232a558029a2f3e88bd8ebfb1 > >>> 100644 > >>> --- a/sound/soc/soc-dapm.c > >>> +++ b/sound/soc/soc-dapm.c > >>> @@ -1147,6 +1147,8 @@ static int dapm_widget_list_create(struct > >>> snd_soc_dapm_widget_list **list, > >>> if (*list == NULL) > >>> return -ENOMEM; > >>> + (*list)->num_widgets = size; > >>> + > >>> list_for_each_entry(w, widgets, work_list) > >>> (*list)->widgets[i++] = w; > >>> > >> > >> and after that there is (*list)->num_widgets = i; > >> > >> Can this be somehow simplified to remove 'i', if it set before assignment? > > > > That line can be removed after this change, I suppose. > > The size is calculated from the list at the beginning, and it must be > > the exact size. > > > > Actually looking at this again, first iteration iterates through all > widgets, while second one, only through work_list, which looks to me > like it allocates more memory than needed in most cases.
Oh, you're right. I don't know why two different loops are used, though... Takashi
