On Wed, 2021-03-24 at 13:17 +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > When CONFIG_OF is disabled, building with 'make W=1' produces warnings > about out of bounds array access: > > drivers/gpu/drm/imx/imx-ldb.c: In function 'imx_ldb_set_clock.constprop': > drivers/gpu/drm/imx/imx-ldb.c:186:8: error: array subscript -22 is below array bounds of 'struct clk *[4]' [-Werror=array-bounds] > > Add an error check before the index is used, which helps with the > warning, as well as any possible other error condition that may be > triggered at runtime. > > The warning could be fixed by adding a Kconfig depedency on CONFIG_OF, > but Liu Ying points out that the driver may hit the out-of-bounds > problem at runtime anyway. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > v2: fix subject line > expand patch description > print mux number > check upper bound as well [] > diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c [] > @@ -197,6 +197,12 @@ static void imx_ldb_encoder_enable(struct drm_encoder *encoder) > int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN; > int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder); > > + if (mux < 0 || mux >= ARRAY_SIZE(ldb->clk_sel)) { > + dev_warn(ldb->dev, "%s: invalid mux %d\n", > + __func__, ERR_PTR(mux)); This does not compile without warnings. drivers/gpu/drm/imx/imx-ldb.c: In function ‘imx_ldb_encoder_enable’: drivers/gpu/drm/imx/imx-ldb.c:201:22: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘void *’ [-Wformat=] 201 | dev_warn(ldb->dev, "%s: invalid mux %d\n", | ^~~~~~~~~~~~~~~~~~~~~~ If you want to use ERR_PTR, the %d should be %pe as ERR_PTR is converting an int a void * to decode the error type and emit it as a string. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel