diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c537a73a62e8..c09182e07b05 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -383,13 +383,12 @@ enum format_type {
 };
 
 struct printf_spec {
-	u8	type;		/* format_type enum */
-	u8	flags;		/* flags to number() */
-	u8	base;		/* number base, 8, 10 or 16 only */
-	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
-	s16	field_width;	/* width of output field */
-	s16	precision;	/* # of digits/chars */
-};
+	unsigned int	type:8;		/* format_type enum */
+	signed int	field_width:24;	/* width of output field */
+	unsigned int	flags:8;	/* flags to number() */
+	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
+	signed int	precision:16;	/* # of digits/chars */
+} __packed;
 
 static noinline_for_stack
 char *number(char *buf, char *end, unsigned long long num,
@@ -403,6 +402,8 @@ char *number(char *buf, char *end, unsigned long long num,
 	int i;
 	bool is_zero = num == 0LL;
 
+	BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
+
 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
 	 * produces same digits or (maybe lowercased) letters */
 	locase = (spec.flags & SMALL);
@@ -1670,6 +1671,7 @@ static noinline_for_stack
 int format_decode(const char *fmt, struct printf_spec *spec)
 {
 	const char *start = fmt;
+	char qualifier;
 
 	/* we finished early by reading the field width */
 	if (spec->type == FORMAT_TYPE_WIDTH) {
@@ -1752,16 +1754,16 @@ precision:
 
 qualifier:
 	/* get the conversion qualifier */
-	spec->qualifier = -1;
+	qualifier = 0;
 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
 	    _tolower(*fmt) == 'z' || *fmt == 't') {
-		spec->qualifier = *fmt++;
-		if (unlikely(spec->qualifier == *fmt)) {
-			if (spec->qualifier == 'l') {
-				spec->qualifier = 'L';
+		qualifier = *fmt++;
+		if (unlikely(qualifier == *fmt)) {
+			if (qualifier == 'l') {
+				qualifier = 'L';
 				++fmt;
-			} else if (spec->qualifier == 'h') {
-				spec->qualifier = 'H';
+			} else if (qualifier == 'h') {
+				qualifier = 'H';
 				++fmt;
 			}
 		}
@@ -1818,19 +1820,19 @@ qualifier:
 		return fmt - start;
 	}
 
-	if (spec->qualifier == 'L')
+	if (qualifier == 'L')
 		spec->type = FORMAT_TYPE_LONG_LONG;
-	else if (spec->qualifier == 'l') {
+	else if (qualifier == 'l') {
 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
-	} else if (_tolower(spec->qualifier) == 'z') {
+	} else if (_tolower(qualifier) == 'z') {
 		spec->type = FORMAT_TYPE_SIZE_T;
-	} else if (spec->qualifier == 't') {
+	} else if (qualifier == 't') {
 		spec->type = FORMAT_TYPE_PTRDIFF;
-	} else if (spec->qualifier == 'H') {
+	} else if (qualifier == 'H') {
 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
-	} else if (spec->qualifier == 'h') {
+	} else if (qualifier == 'h') {
 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
 	} else {