[Spice-devel] [usbredir v2] usbredirhost: Fix coverity sign_extension warning
Victor Toso
victortoso at redhat.com
Wed Aug 3 17:31:54 UTC 2016
Complain from coverity:
usbredir-0.7.1/usbredirhost/usbredirhost.c:1159: sign_extension:
Suspicious implicit sign extension: "max_packetsize" with type
"unsigned short" (16 bits, unsigned) is promoted in
"pkts_per_transfer * transfer_count * max_packetsize" to type "int"
(32 bits, signed), then sign-extended to type "unsigned long"
(64 bits, unsigned). If "pkts_per_transfer * transfer_count *
max_packetsize" is greater than 0x7FFFFFFF, the upper bits of the
result will all be 1.
Pretty sure that reaching 0x7FFFFFFF is improbable but let's make
coverity happy.
---
usbredirhost/usbredirhost.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/usbredirhost/usbredirhost.c b/usbredirhost/usbredirhost.c
index 3e80677..909ebdd 100644
--- a/usbredirhost/usbredirhost.c
+++ b/usbredirhost/usbredirhost.c
@@ -1156,7 +1156,8 @@ static void usbredirhost_stop_stream(struct usbredirhost *host,
static void usbredirhost_set_iso_threshold(struct usbredirhost *host,
uint8_t pkts_per_transfer, uint8_t transfer_count, uint16_t max_packetsize)
{
- uint64_t reference = pkts_per_transfer * transfer_count * max_packetsize;
+ uint64_t reference = ((size_t) (pkts_per_transfer)) * transfer_count * max_packetsize;
+
host->iso_threshold.lower = reference / 2;
host->iso_threshold.higher = reference * 3;
DEBUG("higher threshold is %" PRIu64 " bytes | lower threshold is %" PRIu64 " bytes",
--
2.7.4
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