From d9308d912da2997b944c80b3dd01b80594c9cce1 Mon Sep 17 00:00:00 2001
From: Philippe Teuwen <phil@teuwen.org>
Date: Tue, 12 Mar 2019 23:59:43 +0100
Subject: [PATCH] fix: shifting signed 32-bit value by 31 bits is undefined
 behaviour

---
 armsrc/lfops.c         | 4 ++--
 client/cmdlft55xx.c    | 6 +++---
 client/cmdlfti.c       | 2 +-
 include/at91sam7s512.h | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index b5a905c98..752158929 100644
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -317,7 +317,7 @@ void ReadTItag(void) {
                 // expected for either the low or high frequency
                 if ((samples > (sampleslo - threshold)) && (samples < (sampleslo + threshold))) {
                     // low frequency represents a 1
-                    shift3 |= (1 << 31);
+                    shift3 |= (1u << 31);
                 } else if ((samples > (sampleshi - threshold)) && (samples < (sampleshi + threshold))) {
                     // high frequency represents a 0
                 } else {
@@ -481,7 +481,7 @@ void AcquireTiType(void) {
     // unpack buffer
     for (i = TIBUFLEN - 1; i >= 0; i--) {
         for (j = 0; j < 32; j++) {
-            if (buf[i] & (1 << j)) {
+            if (buf[i] & (1u << j)) {
                 dest[--n] = 1;
             } else {
                 dest[--n] = -1;
diff --git a/client/cmdlft55xx.c b/client/cmdlft55xx.c
index 91f4a456f..41512c6b9 100644
--- a/client/cmdlft55xx.c
+++ b/client/cmdlft55xx.c
@@ -1882,7 +1882,7 @@ int CmdT55xxRecoverPW(const char *Cmd) {
 
     // first try fliping each bit in the expected password
     while (bit < 32) {
-        curr_password = orig_password ^ (1 << bit);
+        curr_password = orig_password ^ (1u << bit);
         found = tryOnePassword(curr_password);
         if (found == -1) return 0;
         bit++;
@@ -1897,7 +1897,7 @@ int CmdT55xxRecoverPW(const char *Cmd) {
     // from low bit to high bit
     bit = 0;
     while (bit < 32) {
-        mask += (1 << bit);
+        mask += (1u << bit);
         curr_password = orig_password & mask;
         // if updated mask didn't change the password, don't try it again
         if (prev_password == curr_password) {
@@ -1916,7 +1916,7 @@ int CmdT55xxRecoverPW(const char *Cmd) {
     bit = 0;
     mask = 0xffffffff;
     while (bit < 32) {
-        mask -= (1 << bit);
+        mask -= (1u << bit);
         curr_password = orig_password & mask;
         // if updated mask didn't change the password, don't try it again
         if (prev_password == curr_password) {
diff --git a/client/cmdlfti.c b/client/cmdlfti.c
index 6abb9b5de..5d3c2e399 100644
--- a/client/cmdlfti.c
+++ b/client/cmdlfti.c
@@ -191,7 +191,7 @@ int CmdTIDemod(const char *Cmd) {
             bits[i] = '1';
             maxPos += highLen;
             // bitstream arrives lsb first so shift right
-            shift3 |= (1 << 31);
+            shift3 |= (1u << 31);
         } else {
             bits[i] = '.';
             maxPos += lowLen;
diff --git a/include/at91sam7s512.h b/include/at91sam7s512.h
index f8fa2e8d4..f9f5f69b1 100644
--- a/include/at91sam7s512.h
+++ b/include/at91sam7s512.h
@@ -375,7 +375,7 @@ typedef struct _AT91S_DBGU {
 #define AT91C_US_TXBUFE       (0x1 << 11) // (DBGU) TXBUFE Interrupt
 #define AT91C_US_RXBUFF       (0x1 << 12) // (DBGU) RXBUFF Interrupt
 #define AT91C_US_COMM_TX      (0x1 << 30) // (DBGU) COMM_TX Interrupt
-#define AT91C_US_COMM_RX      (0x1 << 31) // (DBGU) COMM_RX Interrupt
+#define AT91C_US_COMM_RX      (0x1u << 31) // (DBGU) COMM_RX Interrupt
 // -------- DBGU_IDR : (DBGU Offset: 0xc) Debug Unit Interrupt Disable Register --------
 // -------- DBGU_IMR : (DBGU Offset: 0x10) Debug Unit Interrupt Mask Register --------
 // -------- DBGU_CSR : (DBGU Offset: 0x14) Debug Unit Channel Status Register --------