From 4ee236219f6da367093b503b52fcceb609397c6f Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 26 Jun 2017 14:07:54 -0400 Subject: media: v4l2-fwnode: suppress a warning at OF parsing logic smatch produce this warning: drivers/media/v4l2-core/v4l2-fwnode.c:76 v4l2_fwnode_endpoint_parse_csi_bus() error: buffer overflow 'array' 5 <= u16max That's because, in thesis, the routine might have called with some value at bus->num_data_lanes. That's not the current case. Yet, better to shut up this warning, and make the code more reliable if some future changes might cause a bug. While here, simplify the code a little bit by reading only once from lanes-properties array. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-fwnode.c | 32 ++++++++++++++------------------ include/media/v4l2-fwnode.h | 6 ++++-- 2 files changed, 18 insertions(+), 20 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c index ca755a4832fc..d07c54efaa99 100644 --- a/drivers/media/v4l2-core/v4l2-fwnode.c +++ b/drivers/media/v4l2-core/v4l2-fwnode.c @@ -48,10 +48,9 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode, rval = fwnode_property_read_u32_array(fwnode, "data-lanes", NULL, 0); if (rval > 0) { - u32 array[ARRAY_SIZE(bus->data_lanes)]; + u32 array[MAX_DATA_LANES + 1]; - bus->num_data_lanes = - min_t(int, ARRAY_SIZE(bus->data_lanes), rval); + bus->num_data_lanes = min_t(int, MAX_DATA_LANES, rval); fwnode_property_read_u32_array(fwnode, "data-lanes", array, bus->num_data_lanes); @@ -64,24 +63,21 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode, bus->data_lanes[i] = array[i]; } - } - rval = fwnode_property_read_u32_array(fwnode, "lane-polarities", NULL, - 0); - if (rval > 0) { - u32 array[ARRAY_SIZE(bus->lane_polarities)]; + rval = fwnode_property_read_u32_array(fwnode, + "lane-polarities", array, + 1 + bus->num_data_lanes); + if (rval > 0) { + if (rval != 1 + bus->num_data_lanes /* clock + data */) { + pr_warn("invalid number of lane-polarities entries (need %u, got %u)\n", + 1 + bus->num_data_lanes, rval); + return -EINVAL; + } - if (rval < 1 + bus->num_data_lanes /* clock + data */) { - pr_warn("too few lane-polarities entries (need %u, got %u)\n", - 1 + bus->num_data_lanes, rval); - return -EINVAL; - } - fwnode_property_read_u32_array(fwnode, "lane-polarities", array, - 1 + bus->num_data_lanes); - - for (i = 0; i < 1 + bus->num_data_lanes; i++) - bus->lane_polarities[i] = array[i]; + for (i = 0; i < 1 + bus->num_data_lanes; i++) + bus->lane_polarities[i] = array[i]; + } } if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) { diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h index 29ae22bbbbaf..b373c43f65e8 100644 --- a/include/media/v4l2-fwnode.h +++ b/include/media/v4l2-fwnode.h @@ -26,6 +26,8 @@ struct fwnode_handle; +#define MAX_DATA_LANES 4 + /** * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure * @flags: media bus (V4L2_MBUS_*) flags @@ -37,10 +39,10 @@ struct fwnode_handle; */ struct v4l2_fwnode_bus_mipi_csi2 { unsigned int flags; - unsigned char data_lanes[4]; + unsigned char data_lanes[MAX_DATA_LANES]; unsigned char clock_lane; unsigned short num_data_lanes; - bool lane_polarities[5]; + bool lane_polarities[MAX_DATA_LANES + 1]; }; /** -- cgit v1.2.3-59-g8ed1b