flash/nand/core: fix clang static analyzer warning

core.c:446:
The left operand of '>>' is a garbage value

There are many places where an error code returned from nand->controller
operations are ignored. To keep the change minimal, the error checks are
added only to reading of extended nand info as it was suspected
to be the cause of the warning.

Addition of the error checks did not fix the warning.
scan-build-9 report was inspected and IMHO the warning is bogus:
the term (nand->device->erase_size == 0) cannot give false at line 395
and then evaluate true at line 462. Fixed by zeroing id_buff.

Change-Id: I97ed7ce0fdf1aa23d746d5fb898bacd050e20ae8
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/5518
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>

diff --git a/src/flash/nand/core.c b/src/flash/nand/core.c
index b9ac793f2353a059b7602538e84de0c9f12612eb..baef5d59cbb25ee62800e127029879f0b41989cc 100644 (file)
--- a/src/flash/nand/core.c
+++ b/src/flash/nand/core.c
@@ -263,6 +263,7 @@ int nand_read_status(struct nand_device *nand, uint8_t *status)
                return ERROR_NAND_DEVICE_NOT_PROBED;
 
        /* Send read status command */
+       /* FIXME: errors returned from nand->controller are mostly ignored! */
        nand->controller->command(nand, NAND_CMD_STATUS);
 
        alive_sleep(1);
@@ -301,7 +302,8 @@ static int nand_poll_ready(struct nand_device *nand, int timeout)
 int nand_probe(struct nand_device *nand)
 {
        uint8_t manufacturer_id, device_id;
-       uint8_t id_buff[6];
+       uint8_t id_buff[6] = { 0 };     /* zero buff to silence false warning
+                                        * from clang static analyzer */
        int retval;
        int i;
 
@@ -392,19 +394,34 @@ int nand_probe(struct nand_device *nand)
        if (nand->device->page_size == 0 ||
                        nand->device->erase_size == 0) {
                if (nand->bus_width == 8) {
-                       nand->controller->read_data(nand, id_buff + 3);
-                       nand->controller->read_data(nand, id_buff + 4);
-                       nand->controller->read_data(nand, id_buff + 5);
+                       retval = nand->controller->read_data(nand, id_buff + 3);
+                       if (retval != ERROR_OK)
+                               return retval;
+
+                       retval = nand->controller->read_data(nand, id_buff + 4);
+                       if (retval != ERROR_OK)
+                               return retval;
+
+                       retval = nand->controller->read_data(nand, id_buff + 5);
+                       if (retval != ERROR_OK)
+                               return retval;
+
                } else {
                        uint16_t data_buf;
 
-                       nand->controller->read_data(nand, &data_buf);
+                       retval = nand->controller->read_data(nand, &data_buf);
+                       if (retval != ERROR_OK)
+                               return retval;
                        id_buff[3] = data_buf;
 
-                       nand->controller->read_data(nand, &data_buf);
+                       retval = nand->controller->read_data(nand, &data_buf);
+                       if (retval != ERROR_OK)
+                               return retval;
                        id_buff[4] = data_buf;
 
-                       nand->controller->read_data(nand, &data_buf);
+                       retval = nand->controller->read_data(nand, &data_buf);
+                       if (retval != ERROR_OK)
+                               return retval;
                        id_buff[5] = data_buf >> 8;
                }
        }