[coreboot-gerrit] Change in em100[master]: trace: Handle empty and oversized packets

[Stefan Reinauer (Code Review)]

Stefan Reinauer has submitted this change. ( https://review.coreboot.org/c/em100/+/48587 )

Change subject: trace: Handle empty and oversized packets
......................................................................

trace: Handle empty and oversized packets

Signed-off-by: Stefan Reinauer 
Signed-off-by: Duncan Laurie 
Change-Id: I24f5d5973b47652ff1357756d9a01b85c41c1682
Reviewed-on: https://review.coreboot.org/c/em100/+/48587
Reviewed-by: Furquan Shaikh 
Reviewed-by: Angel Pons 
Tested-by: build bot (Jenkins) 
---
M trace.c
1 file changed, 4 insertions(+), 2 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Furquan Shaikh: Looks good to me, approved
  Angel Pons: Looks good to me, approved

diff --git a/trace.c b/trace.c
index 7ab2f5c..2afdbad 100644
--- a/trace.c
+++ b/trace.c
@@ -195,9 +195,11 @@
    for (report = 0; report < REPORT_BUFFER_COUNT; report++) {
    	data = &reportdata[report][0];
    	count = (data[0] << 8) | data[1];
-		if (count > 1022) {
+		if (!count)
+			continue;
+		if (count > 1023) {
    		printf("Warning: EM100pro sends too much data.\n");
-			count = 1022;
+			count = 1023;
    	}
    	for (i = 0; i < count; i++) {
    		int address_bytes = 0;