On Fri, Mar 20, 2026 at 11:32 AM Kees Cook <[email protected]> wrote:
>
> On Thu, Mar 19, 2026 at 05:49:28PM -0700, Rosen Penev wrote:
> > Change to a flexible array member to allocate once instead of twice.
> >
> > Allows using __counted_by for extra runtime analysis. Move the counting
> > variable assignment to right after allocation as required by
> > __counted_by.
> >
> > Remove + 1 to allocation. It's already done in the previous line.
>
> Are you sure this is an accidental +1? I see the "num_sifr++" that
> happens earlier, but it's not immediately clear why either that or the
> +1 in the original allocation are needed. I'd like to understand why
> either/both are/aren't needed.
Looks like a rebasing mistake to me honestly.
>
> -Kees
>
> >
> > Signed-off-by: Rosen Penev <[email protected]>
> > ---
> > drivers/platform/x86/panasonic-laptop.c | 17 ++++-------------
> > 1 file changed, 4 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/platform/x86/panasonic-laptop.c
> > b/drivers/platform/x86/panasonic-laptop.c
> > index d923ddaa4849..4d663fffbcc8 100644
> > --- a/drivers/platform/x86/panasonic-laptop.c
> > +++ b/drivers/platform/x86/panasonic-laptop.c
> > @@ -248,11 +248,11 @@ struct pcc_acpi {
> > int ac_brightness;
> > int dc_brightness;
> > int current_brightness;
> > - u32 *sinf;
> > struct acpi_device *device;
> > struct input_dev *input_dev;
> > struct backlight_device *backlight;
> > struct platform_device *platform;
> > + u32 sinf[] __counted_by(num_sifr);
> > };
> >
> > /*
> > @@ -1017,21 +1017,15 @@ static int acpi_pcc_hotkey_add(struct acpi_device
> > *device)
> > */
> > num_sifr++;
> >
> > - pcc = kzalloc_obj(struct pcc_acpi);
> > + pcc = kzalloc_flex(*pcc, sinf, num_sifr);
> > if (!pcc) {
> > pr_err("Couldn't allocate mem for pcc");
> > return -ENOMEM;
> > }
> >
> > - pcc->sinf = kcalloc(num_sifr + 1, sizeof(u32), GFP_KERNEL);
> > - if (!pcc->sinf) {
> > - result = -ENOMEM;
> > - goto out_hotkey;
> > - }
> > -
> > + pcc->num_sifr = num_sifr;
> > pcc->device = device;
> > pcc->handle = device->handle;
> > - pcc->num_sifr = num_sifr;
> > device->driver_data = pcc;
> > strscpy(acpi_device_name(device), ACPI_PCC_DEVICE_NAME);
> > strscpy(acpi_device_class(device), ACPI_PCC_CLASS);
> > @@ -1039,7 +1033,7 @@ static int acpi_pcc_hotkey_add(struct acpi_device
> > *device)
> > result = acpi_pcc_init_input(pcc);
> > if (result) {
> > pr_err("Error installing keyinput handler\n");
> > - goto out_sinf;
> > + goto out_hotkey;
> > }
> >
> > if (!acpi_pcc_retrieve_biosdata(pcc)) {
> > @@ -1111,8 +1105,6 @@ static int acpi_pcc_hotkey_add(struct acpi_device
> > *device)
> > backlight_device_unregister(pcc->backlight);
> > out_input:
> > input_unregister_device(pcc->input_dev);
> > -out_sinf:
> > - kfree(pcc->sinf);
> > out_hotkey:
> > kfree(pcc);
> >
> > @@ -1140,7 +1132,6 @@ static void acpi_pcc_hotkey_remove(struct acpi_device
> > *device)
> >
> > input_unregister_device(pcc->input_dev);
> >
> > - kfree(pcc->sinf);
> > kfree(pcc);
> > }
> >
> > --
> > 2.53.0
> >
>
> --
> Kees Cook
