Hoernchen has uploaded this change for review. (
https://gerrit.osmocom.org/c/simtrace2/+/43129?usp=email )
Change subject: firmware: sniffer: fix ~INS procedure byte comparison
......................................................................
firmware: sniffer: fix ~INS procedure byte comparison
(~g_tpdu.packet[1]) == byte can never be true.
Unary ~ applies the integer promotions first,
so for tpdu INS = 0xA4 lhs should be 0x5B but as int
it gets zero extended to at least 16 bits and then flipped,
so it is 0xFFFFFF5B = -165, byte promotes to 0..255.
The ack was therefore dead code -> fallthrough to SW1
branch, fails 0x6x/0x9x test, TPDU gets flagged
SNIFF_DATA_FLAG_ERROR_MALFORMED from what I can tell.
But I am losing track of all these arcane issues to be honest.
Narrow the complement back to 8 bits.
Fyi this is unrelated to signedness and not specific to ARM.
Change-Id: I800f50ef35356429d07aa685ea919e70ec34946e
---
M firmware/libcommon/source/sniffer.c
1 file changed, 1 insertion(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/simtrace2 refs/changes/29/43129/1
diff --git a/firmware/libcommon/source/sniffer.c
b/firmware/libcommon/source/sniffer.c
index 948eee8..419e8fb 100644
--- a/firmware/libcommon/source/sniffer.c
+++ b/firmware/libcommon/source/sniffer.c
@@ -775,7 +775,7 @@
} else if (g_tpdu.packet[1] == byte) { /* get all remaining
data bytes */
change_tpdu_state(TPDU_S_DATA_REMAINING);
break;
- } else if ((~g_tpdu.packet[1]) == byte) { /* get single data
byte */
+ } else if ((uint8_t)(~g_tpdu.packet[1]) == byte) { /* get
single data byte */
change_tpdu_state(TPDU_S_DATA_SINGLE);
break;
}
--
To view, visit https://gerrit.osmocom.org/c/simtrace2/+/43129?usp=email
To unsubscribe, or for help writing mail filters, visit
https://gerrit.osmocom.org/settings?usp=email
Gerrit-MessageType: newchange
Gerrit-Project: simtrace2
Gerrit-Branch: master
Gerrit-Change-Id: I800f50ef35356429d07aa685ea919e70ec34946e
Gerrit-Change-Number: 43129
Gerrit-PatchSet: 1
Gerrit-Owner: Hoernchen <[email protected]>
