[PATCH AUTOSEL 5.16 012/109] usb: cdnsp: fix cdnsp_decode_trb function to properly handle ret value

From: Sasha Levin
Date: Fri Apr 01 2022 - 11:02:20 EST


From: Pawel Laszczak <pawell@xxxxxxxxxxx>

[ Upstream commit 03db9289b5ab59437e42a111a34545a7cedb5190 ]

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@xxxxxxxxx>
Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220112053237.14309-1-pawell@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/cdns3/cdnsp-debug.h | 305 ++++++++++++++++----------------
1 file changed, 154 insertions(+), 151 deletions(-)

diff --git a/drivers/usb/cdns3/cdnsp-debug.h b/drivers/usb/cdns3/cdnsp-debug.h
index a8776df2d4e0..f0ca865cce2a 100644
--- 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;
}

--
2.34.1