usb: cdnsp: fix cdnsp_decode_trb function to properly handle ret value

Variable ret in function cdnsp_decode_trb is initialized but not
used. To fix this compiler warning patch adds checking whether the
data buffer has not been overflowed.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Link: https://lore.kernel.org/r/20220112053237.14309-1-pawell@gli-login.cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/cdns3/cdnsp-debug.h b/drivers/usb/cdns3/cdnsp-debug.h
index a8776df..f0ca865 100644 (file)
--- a/drivers/usb/cdns3/cdnsp-debug.h
+++ b/drivers/usb/cdns3/cdnsp-debug.h
@@ -182,208 +182,211 @@ static inline const char *cdnsp_decode_trb(char *str, size_t size, u32 field0,
        int ep_id = TRB_TO_EP_INDEX(field3) - 1;
        int type = TRB_FIELD_TO_TYPE(field3);
        unsigned int ep_num;
-       int ret = 0;
+       int ret;
        u32 temp;
 
        ep_num = DIV_ROUND_UP(ep_id, 2);
 
        switch (type) {
        case TRB_LINK:
-               ret += snprintf(str, size,
-                               "LINK %08x%08x intr %ld type '%s' flags %c:%c:%c:%c",
-                               field1, field0, GET_INTR_TARGET(field2),
-                               cdnsp_trb_type_string(type),
-                               field3 & TRB_IOC ? 'I' : 'i',
-                               field3 & TRB_CHAIN ? 'C' : 'c',
-                               field3 & TRB_TC ? 'T' : 't',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "LINK %08x%08x intr %ld type '%s' flags %c:%c:%c:%c",
+                              field1, field0, GET_INTR_TARGET(field2),
+                              cdnsp_trb_type_string(type),
+                              field3 & TRB_IOC ? 'I' : 'i',
+                              field3 & TRB_CHAIN ? 'C' : 'c',
+                              field3 & TRB_TC ? 'T' : 't',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_TRANSFER:
        case TRB_COMPLETION:
        case TRB_PORT_STATUS:
        case TRB_HC_EVENT:
-               ret += snprintf(str, size,
-                               "ep%d%s(%d) type '%s' TRB %08x%08x status '%s'"
-                               " len %ld slot %ld flags %c:%c",
-                               ep_num, ep_id % 2 ? "out" : "in",
-                               TRB_TO_EP_INDEX(field3),
-                               cdnsp_trb_type_string(type), field1, field0,
-                               cdnsp_trb_comp_code_string(GET_COMP_CODE(field2)),
-                               EVENT_TRB_LEN(field2), TRB_TO_SLOT_ID(field3),
-                               field3 & EVENT_DATA ? 'E' : 'e',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "ep%d%s(%d) type '%s' TRB %08x%08x status '%s'"
+                              " len %ld slot %ld flags %c:%c",
+                              ep_num, ep_id % 2 ? "out" : "in",
+                              TRB_TO_EP_INDEX(field3),
+                              cdnsp_trb_type_string(type), field1, field0,
+                              cdnsp_trb_comp_code_string(GET_COMP_CODE(field2)),
+                              EVENT_TRB_LEN(field2), TRB_TO_SLOT_ID(field3),
+                              field3 & EVENT_DATA ? 'E' : 'e',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_MFINDEX_WRAP:
-               ret += snprintf(str, size, "%s: flags %c",
-                               cdnsp_trb_type_string(type),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size, "%s: flags %c",
+                              cdnsp_trb_type_string(type),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_SETUP:
-               ret += snprintf(str, size,
-                               "type '%s' bRequestType %02x bRequest %02x "
-                               "wValue %02x%02x wIndex %02x%02x wLength %d "
-                               "length %ld TD size %ld intr %ld Setup ID %ld "
-                               "flags %c:%c:%c",
-                               cdnsp_trb_type_string(type),
-                               field0 & 0xff,
-                               (field0 & 0xff00) >> 8,
-                               (field0 & 0xff000000) >> 24,
-                               (field0 & 0xff0000) >> 16,
-                               (field1 & 0xff00) >> 8,
-                               field1 & 0xff,
-                               (field1 & 0xff000000) >> 16 |
-                               (field1 & 0xff0000) >> 16,
-                               TRB_LEN(field2), GET_TD_SIZE(field2),
-                               GET_INTR_TARGET(field2),
-                               TRB_SETUPID_TO_TYPE(field3),
-                               field3 & TRB_IDT ? 'D' : 'd',
-                               field3 & TRB_IOC ? 'I' : 'i',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "type '%s' bRequestType %02x bRequest %02x "
+                              "wValue %02x%02x wIndex %02x%02x wLength %d "
+                              "length %ld TD size %ld intr %ld Setup ID %ld "
+                              "flags %c:%c:%c",
+                              cdnsp_trb_type_string(type),
+                              field0 & 0xff,
+                              (field0 & 0xff00) >> 8,
+                              (field0 & 0xff000000) >> 24,
+                              (field0 & 0xff0000) >> 16,
+                              (field1 & 0xff00) >> 8,
+                              field1 & 0xff,
+                              (field1 & 0xff000000) >> 16 |
+                              (field1 & 0xff0000) >> 16,
+                              TRB_LEN(field2), GET_TD_SIZE(field2),
+                              GET_INTR_TARGET(field2),
+                              TRB_SETUPID_TO_TYPE(field3),
+                              field3 & TRB_IDT ? 'D' : 'd',
+                              field3 & TRB_IOC ? 'I' : 'i',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_DATA:
-               ret += snprintf(str, size,
-                               "type '%s' Buffer %08x%08x length %ld TD size %ld "
-                               "intr %ld flags %c:%c:%c:%c:%c:%c:%c",
-                               cdnsp_trb_type_string(type),
-                               field1, field0, TRB_LEN(field2),
-                               GET_TD_SIZE(field2),
-                               GET_INTR_TARGET(field2),
-                               field3 & TRB_IDT ? 'D' : 'i',
-                               field3 & TRB_IOC ? 'I' : 'i',
-                               field3 & TRB_CHAIN ? 'C' : 'c',
-                               field3 & TRB_NO_SNOOP ? 'S' : 's',
-                               field3 & TRB_ISP ? 'I' : 'i',
-                               field3 & TRB_ENT ? 'E' : 'e',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "type '%s' Buffer %08x%08x length %ld TD size %ld "
+                              "intr %ld flags %c:%c:%c:%c:%c:%c:%c",
+                              cdnsp_trb_type_string(type),
+                              field1, field0, TRB_LEN(field2),
+                              GET_TD_SIZE(field2),
+                              GET_INTR_TARGET(field2),
+                              field3 & TRB_IDT ? 'D' : 'i',
+                              field3 & TRB_IOC ? 'I' : 'i',
+                              field3 & TRB_CHAIN ? 'C' : 'c',
+                              field3 & TRB_NO_SNOOP ? 'S' : 's',
+                              field3 & TRB_ISP ? 'I' : 'i',
+                              field3 & TRB_ENT ? 'E' : 'e',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_STATUS:
-               ret += snprintf(str, size,
-                               "Buffer %08x%08x length %ld TD size %ld intr"
-                               "%ld type '%s' flags %c:%c:%c:%c",
-                               field1, field0, TRB_LEN(field2),
-                               GET_TD_SIZE(field2),
-                               GET_INTR_TARGET(field2),
-                               cdnsp_trb_type_string(type),
-                               field3 & TRB_IOC ? 'I' : 'i',
-                               field3 & TRB_CHAIN ? 'C' : 'c',
-                               field3 & TRB_ENT ? 'E' : 'e',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "Buffer %08x%08x length %ld TD size %ld intr"
+                              "%ld type '%s' flags %c:%c:%c:%c",
+                              field1, field0, TRB_LEN(field2),
+                              GET_TD_SIZE(field2),
+                              GET_INTR_TARGET(field2),
+                              cdnsp_trb_type_string(type),
+                              field3 & TRB_IOC ? 'I' : 'i',
+                              field3 & TRB_CHAIN ? 'C' : 'c',
+                              field3 & TRB_ENT ? 'E' : 'e',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_NORMAL:
        case TRB_ISOC:
        case TRB_EVENT_DATA:
        case TRB_TR_NOOP:
-               ret += snprintf(str, size,
-                               "type '%s' Buffer %08x%08x length %ld "
-                               "TD size %ld intr %ld "
-                               "flags %c:%c:%c:%c:%c:%c:%c:%c:%c",
-                               cdnsp_trb_type_string(type),
-                               field1, field0, TRB_LEN(field2),
-                               GET_TD_SIZE(field2),
-                               GET_INTR_TARGET(field2),
-                               field3 & TRB_BEI ? 'B' : 'b',
-                               field3 & TRB_IDT ? 'T' : 't',
-                               field3 & TRB_IOC ? 'I' : 'i',
-                               field3 & TRB_CHAIN ? 'C' : 'c',
-                               field3 & TRB_NO_SNOOP ? 'S' : 's',
-                               field3 & TRB_ISP ? 'I' : 'i',
-                               field3 & TRB_ENT ? 'E' : 'e',
-                               field3 & TRB_CYCLE ? 'C' : 'c',
-                               !(field3 & TRB_EVENT_INVALIDATE) ? 'V' : 'v');
+               ret = snprintf(str, size,
+                              "type '%s' Buffer %08x%08x length %ld "
+                              "TD size %ld intr %ld "
+                              "flags %c:%c:%c:%c:%c:%c:%c:%c:%c",
+                              cdnsp_trb_type_string(type),
+                              field1, field0, TRB_LEN(field2),
+                              GET_TD_SIZE(field2),
+                              GET_INTR_TARGET(field2),
+                              field3 & TRB_BEI ? 'B' : 'b',
+                              field3 & TRB_IDT ? 'T' : 't',
+                              field3 & TRB_IOC ? 'I' : 'i',
+                              field3 & TRB_CHAIN ? 'C' : 'c',
+                              field3 & TRB_NO_SNOOP ? 'S' : 's',
+                              field3 & TRB_ISP ? 'I' : 'i',
+                              field3 & TRB_ENT ? 'E' : 'e',
+                              field3 & TRB_CYCLE ? 'C' : 'c',
+                              !(field3 & TRB_EVENT_INVALIDATE) ? 'V' : 'v');
                break;
        case TRB_CMD_NOOP:
        case TRB_ENABLE_SLOT:
-               ret += snprintf(str, size, "%s: flags %c",
-                               cdnsp_trb_type_string(type),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size, "%s: flags %c",
+                              cdnsp_trb_type_string(type),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_DISABLE_SLOT:
-               ret += snprintf(str, size, "%s: slot %ld flags %c",
-                               cdnsp_trb_type_string(type),
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size, "%s: slot %ld flags %c",
+                              cdnsp_trb_type_string(type),
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_ADDR_DEV:
-               ret += snprintf(str, size,
-                               "%s: ctx %08x%08x slot %ld flags %c:%c",
-                               cdnsp_trb_type_string(type), field1, field0,
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_BSR ? 'B' : 'b',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "%s: ctx %08x%08x slot %ld flags %c:%c",
+                              cdnsp_trb_type_string(type), field1, field0,
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_BSR ? 'B' : 'b',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_CONFIG_EP:
-               ret += snprintf(str, size,
-                               "%s: ctx %08x%08x slot %ld flags %c:%c",
-                               cdnsp_trb_type_string(type), field1, field0,
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_DC ? 'D' : 'd',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "%s: ctx %08x%08x slot %ld flags %c:%c",
+                              cdnsp_trb_type_string(type), field1, field0,
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_DC ? 'D' : 'd',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_EVAL_CONTEXT:
-               ret += snprintf(str, size,
-                               "%s: ctx %08x%08x slot %ld flags %c",
-                               cdnsp_trb_type_string(type), field1, field0,
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "%s: ctx %08x%08x slot %ld flags %c",
+                              cdnsp_trb_type_string(type), field1, field0,
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_RESET_EP:
        case TRB_HALT_ENDPOINT:
        case TRB_FLUSH_ENDPOINT:
-               ret += snprintf(str, size,
-                               "%s: ep%d%s(%d) ctx %08x%08x slot %ld flags %c",
-                               cdnsp_trb_type_string(type),
-                               ep_num, ep_id % 2 ? "out" : "in",
-                               TRB_TO_EP_INDEX(field3), field1, field0,
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "%s: ep%d%s(%d) ctx %08x%08x slot %ld flags %c",
+                              cdnsp_trb_type_string(type),
+                              ep_num, ep_id % 2 ? "out" : "in",
+                              TRB_TO_EP_INDEX(field3), field1, field0,
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_STOP_RING:
-               ret += snprintf(str, size,
-                               "%s: ep%d%s(%d) slot %ld sp %d flags %c",
-                               cdnsp_trb_type_string(type),
-                               ep_num, ep_id % 2 ? "out" : "in",
-                               TRB_TO_EP_INDEX(field3),
-                               TRB_TO_SLOT_ID(field3),
-                               TRB_TO_SUSPEND_PORT(field3),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "%s: ep%d%s(%d) slot %ld sp %d flags %c",
+                              cdnsp_trb_type_string(type),
+                              ep_num, ep_id % 2 ? "out" : "in",
+                              TRB_TO_EP_INDEX(field3),
+                              TRB_TO_SLOT_ID(field3),
+                              TRB_TO_SUSPEND_PORT(field3),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_SET_DEQ:
-               ret += snprintf(str, size,
-                               "%s: ep%d%s(%d) deq %08x%08x stream %ld slot %ld  flags %c",
-                               cdnsp_trb_type_string(type),
-                               ep_num, ep_id % 2 ? "out" : "in",
-                               TRB_TO_EP_INDEX(field3), field1, field0,
-                               TRB_TO_STREAM_ID(field2),
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size,
+                              "%s: ep%d%s(%d) deq %08x%08x stream %ld slot %ld  flags %c",
+                              cdnsp_trb_type_string(type),
+                              ep_num, ep_id % 2 ? "out" : "in",
+                              TRB_TO_EP_INDEX(field3), field1, field0,
+                              TRB_TO_STREAM_ID(field2),
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_RESET_DEV:
-               ret += snprintf(str, size, "%s: slot %ld flags %c",
-                               cdnsp_trb_type_string(type),
-                               TRB_TO_SLOT_ID(field3),
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               ret = snprintf(str, size, "%s: slot %ld flags %c",
+                              cdnsp_trb_type_string(type),
+                              TRB_TO_SLOT_ID(field3),
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        case TRB_ENDPOINT_NRDY:
-               temp  = TRB_TO_HOST_STREAM(field2);
-
-               ret += snprintf(str, size,
-                               "%s: ep%d%s(%d) H_SID %x%s%s D_SID %lx flags %c:%c",
-                               cdnsp_trb_type_string(type),
-                               ep_num, ep_id % 2 ? "out" : "in",
-                               TRB_TO_EP_INDEX(field3), temp,
-                               temp == STREAM_PRIME_ACK ? "(PRIME)" : "",
-                               temp == STREAM_REJECTED ? "(REJECTED)" : "",
-                               TRB_TO_DEV_STREAM(field0),
-                               field3 & TRB_STAT ? 'S' : 's',
-                               field3 & TRB_CYCLE ? 'C' : 'c');
+               temp = TRB_TO_HOST_STREAM(field2);
+
+               ret = snprintf(str, size,
+                              "%s: ep%d%s(%d) H_SID %x%s%s D_SID %lx flags %c:%c",
+                              cdnsp_trb_type_string(type),
+                              ep_num, ep_id % 2 ? "out" : "in",
+                              TRB_TO_EP_INDEX(field3), temp,
+                              temp == STREAM_PRIME_ACK ? "(PRIME)" : "",
+                              temp == STREAM_REJECTED ? "(REJECTED)" : "",
+                              TRB_TO_DEV_STREAM(field0),
+                              field3 & TRB_STAT ? 'S' : 's',
+                              field3 & TRB_CYCLE ? 'C' : 'c');
                break;
        default:
-               ret += snprintf(str, size,
-                               "type '%s' -> raw %08x %08x %08x %08x",
-                               cdnsp_trb_type_string(type),
-                               field0, field1, field2, field3);
+               ret = snprintf(str, size,
+                              "type '%s' -> raw %08x %08x %08x %08x",
+                              cdnsp_trb_type_string(type),
+                              field0, field1, field2, field3);
        }
 
+       if (ret >= size)
+               pr_info("CDNSP: buffer overflowed.\n");
+
        return str;
 }