From: Uwe Kleine-König <uwe@xxxxxxxxxxxxxxxxx>
Before commit e42ee61017f5 ("of: Let of_for_each_phandle fallback to
non-negative cell_count") the iterator functions calling
of_for_each_phandle assumed a cell count of 0 if cells_name was NULL.
This corner case was missed when implementing the fallback logic in
e42ee61017f5 and resulted in an endless loop.
Restore the old behaviour of of_count_phandle_with_args() and
of_parse_phandle_with_args() and add a check to
of_phandle_iterator_init() to prevent a similar failure as a safety
precaution. of_parse_phandle_with_args_map() doesn't need a similar fix
as cells_name isn't NULL there.
Affected drivers are:
- drivers/base/power/domain.c
- drivers/base/power/domain.c
- drivers/clk/ti/clk-dra7-atl.c
- drivers/hwmon/ibmpowernv.c
- drivers/i2c/muxes/i2c-demux-pinctrl.c
- drivers/iommu/mtk_iommu.c
- drivers/net/ethernet/freescale/fman/mac.c
- drivers/opp/of.c
- drivers/perf/arm_dsu_pmu.c
- drivers/regulator/of_regulator.c
- drivers/remoteproc/imx_rproc.c
- drivers/soc/rockchip/pm_domains.c
- sound/soc/fsl/imx-audmix.c
- sound/soc/fsl/imx-audmix.c
- sound/soc/meson/axg-card.c
- sound/soc/samsung/tm2_wm5110.c
- sound/soc/samsung/tm2_wm5110.c
Thanks to Geert Uytterhoeven for reporting the issue, Peter Rosin for
helping pinpoint the actual problem and the testers for confirming this
fix.
Fixes: e42ee61017f5 ("of: Let of_for_each_phandle fallback to non-negative cell_count")
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
Hello,
compared to the untested patch I sent yesterday I also fixed
of_parse_phandle_with_args which has three users that pass
cells_name=NULL. (i.e. drivers/clk/ti/clk-dra7-atl.c,
sound/soc/fsl/imx-audmix.c, sound/soc/samsung/tm2_wm5110.c) I didn't
look closely, but maybe these could be converted to use of_parse_phandle
as there are no arguments to be processed with no cells_name?!
Best regards
Uwe
drivers/of/base.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 2f25d2dfecfa..25ee07c0a3cd 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1286,6 +1286,13 @@ int of_phandle_iterator_init(struct of_phandle_iterator *it,
memset(it, 0, sizeof(*it));
+ /*
+ * one of cell_count or cells_name must be provided to determine the
+ * argument length.
+ */
+ if (cell_count < 0 && !cells_name)
+ return -EINVAL;
+
list = of_get_property(np, list_name, &size);
if (!list)
return -ENOENT;
@@ -1512,10 +1519,17 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
const char *cells_name, int index,
struct of_phandle_args *out_args)
{
+ int cell_count = -1;
+
if (index < 0)
return -EINVAL;
- return __of_parse_phandle_with_args(np, list_name, cells_name, -1,
- index, out_args);
+
+ /* If cells_name if NULL we assume a cell count of 0 */
+ if (!cells_name)
+ cell_count = 0;
+
+ return __of_parse_phandle_with_args(np, list_name, cells_name,
+ cell_count, index, out_args);
}
EXPORT_SYMBOL(of_parse_phandle_with_args);
@@ -1765,6 +1779,18 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
struct of_phandle_iterator it;
int rc, cur_index = 0;
+ /* If cells_name is NULL we assume a cell count of 0 */
+ if (cells_name == NULL) {
+ const __be32 *list;
+ int size;
+
+ list = of_get_property(np, list_name, &size);
+ if (!list)
+ return -ENOENT;
+
+ return size / sizeof(*list);
+ }
+
rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
if (rc)
return rc;
--
2.23.0
