nvmutil: macro safety

maximum safety.

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/nvmutil/nvmutil.c

@@ -77,26 +77,41 @@ op_t op[] = {
 };
 void (*cmd)(void) = NULL;
 
-#define err_if(x) if (x) err(EXIT_FAILURE, "%s", filename)
+#define err_if(x) \
+	do { \
+		if (x) { \
+			err(EXIT_FAILURE, "%s", filename); \
+		} \
+	} while(0)
 
 #define xopen(f,l,p) \
 	do { \
-	if ((f = open_on_eintr(l, p)) == -1) \
+		if ((f = open_on_eintr(l, p)) == -1) { \
-		err(EXIT_FAILURE, "%s", l); \
+			err(EXIT_FAILURE, "%s", l); \
-	if (fstat(f, &st) == -1) \
+		} \
-		err(EXIT_FAILURE, "%s", l); \
+		if (fstat(f, &st) == -1) { \
+			err(EXIT_FAILURE, "%s", l); \
+		} \
 	} while(0)
 
-#define word(pos16, partnum) ((uint16_t *) gbe[partnum])[pos16]
+#define word(pos16, partnum) \
-#define setWord(pos16, p, val16) if (word(pos16, p) != val16) \
+	(((uint16_t *) gbe[partnum])[pos16])
-    nvmPartChanged[p] = 1 | (word(pos16, p) = val16)
 
-#define SUCCESS(x) ((x) >= 0)
+#define setWord(pos16, p, val16) \
+	do { \
+		if (word(pos16, p) != val16) { \
+			nvmPartChanged[p] = 1 | (word(pos16, p) = val16); \
+		} \
+	} while(0)
+
+#define SUCCESS(x) \
+	((x) >= 0)
 
 #define reset_caller_errno(return_value) \
 	do { \
-	if (SUCCESS(return_value) && (!errno)) \
+		if (SUCCESS(return_value) && (!errno)) { \
-		errno = saved_errno; \
+			errno = saved_errno; \
+		} \
 	} while (0)
 
 int
@@ -283,7 +298,7 @@ cmd_setmac(void)
 	if (mac_updated)
 		return;
 
-	errno = EINVAL;
+	errno = ECANCELED;
 	err(EXIT_FAILURE, "Error updating MAC address");
 }
 
@@ -376,6 +391,11 @@ cmd_dump(void)
 		printf("MAC (part %d): ", partnum);
 		macf(partnum);
 		hexdump(partnum);
+
+		if (numInvalid > 1) {
+			errno = EINVAL;
+			err(EXIT_FAILURE, "dump: No valid checksums");
+		}
 	}
 }
 
@@ -407,6 +427,7 @@ hexdump(int partnum)
 	}
 }
 
+/* WARNING: Cannot fail. Make sure the file is valid. */
 void
 cmd_setchecksum(void)
 {
@@ -420,22 +441,30 @@ cmd_setchecksum(void)
 void
 cmd_brick(void)
 {
-	if (goodChecksum(part))
+	if (goodChecksum(part)) {
 		setWord(NVM_CHECKSUM_WORD, part,
 		    ((word(NVM_CHECKSUM_WORD, part)) ^ 0xFF));
+	} else {
+		errno = ECANCELED;
+		err(EXIT_FAILURE, "brick: Bad checksum in part %d", part);
+	}
 }
 
 void
 cmd_copy(void)
 {
 	nvmPartChanged[part ^ 1] = goodChecksum(part);
+	if (!nvmPartChanged[part ^ 1]) {
+		errno = ECANCELED;
+		err(EXIT_FAILURE, "copy: Bad checksum in part %d", part);
+	}
 }
 
 void
 cmd_swap(void) {
 	if(!(goodChecksum(0) || goodChecksum(1))) {
-		errno = EINVAL;
+		errno = ECANCELED;
-		err(EXIT_FAILURE, "Invalid checksums");
+		err(EXIT_FAILURE, "swap: Bad checksums");
 	}
 
 	gbe[0] ^= gbe[1];
@@ -502,8 +531,10 @@ xclose(int *fd)
 	int saved_errno = errno;
 	int rval = 0;
 
-	if (fd == NULL)
+	if (fd == NULL) {
+		errno = EBADF;
 		err(EXIT_FAILURE, "xclose: null pointer");
+	}
 	if (*fd < 0)
 		return;
 
@@ -710,21 +741,24 @@ if_err_sys(int condition)
 #define fs_err_retry() \
 	do { \
 		if ((rval == -1) && \
-		    (errno == EINTR)) \
+		    (errno == EINTR)) { \
 			return 1; \
-		if (rval >= 0 && !errno) \
+		} \
+		if (rval >= 0 && !errno) { \
 			errno = saved_errno; \
-		return 0; \
+		} \
 	} while(0)
 
 int
 fs_retry(int saved_errno, int rval)
 {
 	fs_err_retry();
+	return 0;
 }
 
 int
 rw_retry(int saved_errno, ssize_t rval)
 {
 	fs_err_retry();
+	return 0;
 }