Merge branch 'vsnprintf'

This merges the vsnprintf internal cleanups I did, which were triggered
by a combination of performance issues (see for example commit
f9ed1f7c2e26: "genirq/proc: Use seq_put_decimal_ull_width() for decimal
values") and discussion about tracing abusing the vsnprintf code in odd
ways.

The intent was to improve code generation, but also to possibly
eventually expose the cleaned-up printf format decoding state machine.

It certainly didn't get to the point where we'd want to expose the
format decoding to external users, but it's an improvement over what we
used to have.  Several of the complex case statements have been
simplified, or removed entirely to be replaced by simple table lookups.

* branch 'vsnprintf':
  vsnprintf: fix the number base for non-numeric formats
  vsnprintf: fix up kerneldoc for argument name changes
  vsprintf: don't make the 'binary' version pack small integer arguments
  vsnprintf: collapse the number format state into one single state
  vsnprintf: mark the indirect width and precision cases unlikely
  vsnprintf: inline skip_atoi() again
  vsprintf: deal with format specifiers with a lookup table
  vsprintf: deal with format flags with a simple lookup table
  vsprintf: associate the format state with the format pointer
  vsprintf: fix calling convention for format_decode()
  vsprintf: avoid nested switch statement on same variable
  vsprintf: simplify number handling

1 files changed, 241 insertions, 333 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 9d3dac38a3f4..56fe96319292 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -160,8 +160,7 @@ long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 }
 EXPORT_SYMBOL(simple_strtoll);
 
-static noinline_for_stack
-int skip_atoi(const char **s)
+static inline int skip_atoi(const char **s)
 {
 	int i = 0;
 
@@ -407,7 +406,7 @@ int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 	return len + width;
 }
 
-#define SIGN	1		/* unsigned/signed, must be 1 */
+#define SIGN	1		/* unsigned/signed */
 #define LEFT	2		/* left justified */
 #define PLUS	4		/* show plus */
 #define SPACE	8		/* space if plus */
@@ -415,38 +414,26 @@ int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
 
-static_assert(SIGN == 1);
 static_assert(ZEROPAD == ('0' - ' '));
 static_assert(SMALL == ('a' ^ 'A'));
 
-enum format_type {
-	FORMAT_TYPE_NONE, /* Just a string part */
-	FORMAT_TYPE_WIDTH,
-	FORMAT_TYPE_PRECISION,
-	FORMAT_TYPE_CHAR,
-	FORMAT_TYPE_STR,
-	FORMAT_TYPE_PTR,
-	FORMAT_TYPE_PERCENT_CHAR,
-	FORMAT_TYPE_INVALID,
-	FORMAT_TYPE_LONG_LONG,
-	FORMAT_TYPE_ULONG,
-	FORMAT_TYPE_LONG,
-	FORMAT_TYPE_UBYTE,
-	FORMAT_TYPE_BYTE,
-	FORMAT_TYPE_USHORT,
-	FORMAT_TYPE_SHORT,
-	FORMAT_TYPE_UINT,
-	FORMAT_TYPE_INT,
-	FORMAT_TYPE_SIZE_T,
-	FORMAT_TYPE_PTRDIFF
+enum format_state {
+	FORMAT_STATE_NONE, /* Just a string part */
+	FORMAT_STATE_NUM,
+	FORMAT_STATE_WIDTH,
+	FORMAT_STATE_PRECISION,
+	FORMAT_STATE_CHAR,
+	FORMAT_STATE_STR,
+	FORMAT_STATE_PTR,
+	FORMAT_STATE_PERCENT_CHAR,
+	FORMAT_STATE_INVALID,
 };
 
 struct printf_spec {
-	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 */
+	unsigned char	flags;		/* flags to number() */
+	unsigned char	base;		/* number base, 8, 10 or 16 only */
+	short		precision;	/* # of digits/chars */
+	int		field_width;	/* width of output field */
 } __packed;
 static_assert(sizeof(struct printf_spec) == 8);
 
@@ -579,7 +566,6 @@ char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 {
 	struct printf_spec spec;
 
-	spec.type = FORMAT_TYPE_PTR;
 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
 	spec.flags = SPECIAL | SMALL | ZEROPAD;
 	spec.base = 16;
@@ -2530,6 +2516,26 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 	}
 }
 
+struct fmt {
+	const char *str;
+	unsigned char state;	// enum format_state
+	unsigned char size;	// size of numbers
+};
+
+#define SPEC_CHAR(x, flag) [(x)-32] = flag
+static unsigned char spec_flag(unsigned char c)
+{
+	static const unsigned char spec_flag_array[] = {
+		SPEC_CHAR(' ', SPACE),
+		SPEC_CHAR('#', SPECIAL),
+		SPEC_CHAR('+', PLUS),
+		SPEC_CHAR('-', LEFT),
+		SPEC_CHAR('0', ZEROPAD),
+	};
+	c -= 32;
+	return (c < sizeof(spec_flag_array)) ? spec_flag_array[c] : 0;
+}
+
 /*
  * Helper function to decode printf style format.
  * Each call decode a token from the format and return the
@@ -2552,181 +2558,141 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
  * @qualifier: qualifier of a number (long, size_t, ...)
  */
 static noinline_for_stack
-int format_decode(const char *fmt, struct printf_spec *spec)
+struct fmt format_decode(struct fmt fmt, struct printf_spec *spec)
 {
-	const char *start = fmt;
-	char qualifier;
+	const char *start = fmt.str;
+	char flag;
 
 	/* we finished early by reading the field width */
-	if (spec->type == FORMAT_TYPE_WIDTH) {
+	if (unlikely(fmt.state == FORMAT_STATE_WIDTH)) {
 		if (spec->field_width < 0) {
 			spec->field_width = -spec->field_width;
 			spec->flags |= LEFT;
 		}
-		spec->type = FORMAT_TYPE_NONE;
+		fmt.state = FORMAT_STATE_NONE;
 		goto precision;
 	}
 
 	/* we finished early by reading the precision */
-	if (spec->type == FORMAT_TYPE_PRECISION) {
+	if (unlikely(fmt.state == FORMAT_STATE_PRECISION)) {
 		if (spec->precision < 0)
 			spec->precision = 0;
 
-		spec->type = FORMAT_TYPE_NONE;
+		fmt.state = FORMAT_STATE_NONE;
 		goto qualifier;
 	}
 
 	/* By default */
-	spec->type = FORMAT_TYPE_NONE;
+	fmt.state = FORMAT_STATE_NONE;
 
-	for (; *fmt ; ++fmt) {
-		if (*fmt == '%')
+	for (; *fmt.str ; fmt.str++) {
+		if (*fmt.str == '%')
 			break;
 	}
 
 	/* Return the current non-format string */
-	if (fmt != start || !*fmt)
-		return fmt - start;
+	if (fmt.str != start || !*fmt.str)
+		return fmt;
 
-	/* Process flags */
+	/* Process flags. This also skips the first '%' */
 	spec->flags = 0;
-
-	while (1) { /* this also skips first '%' */
-		bool found = true;
-
-		++fmt;
-
-		switch (*fmt) {
-		case '-': spec->flags |= LEFT;    break;
-		case '+': spec->flags |= PLUS;    break;
-		case ' ': spec->flags |= SPACE;   break;
-		case '#': spec->flags |= SPECIAL; break;
-		case '0': spec->flags |= ZEROPAD; break;
-		default:  found = false;
-		}
-
-		if (!found)
-			break;
-	}
+	do {
+		/* this also skips first '%' */
+		flag = spec_flag(*++fmt.str);
+		spec->flags |= flag;
+	} while (flag);
 
 	/* get field width */
 	spec->field_width = -1;
 
-	if (isdigit(*fmt))
-		spec->field_width = skip_atoi(&fmt);
-	else if (*fmt == '*') {
+	if (isdigit(*fmt.str))
+		spec->field_width = skip_atoi(&fmt.str);
+	else if (unlikely(*fmt.str == '*')) {
 		/* it's the next argument */
-		spec->type = FORMAT_TYPE_WIDTH;
-		return ++fmt - start;
+		fmt.state = FORMAT_STATE_WIDTH;
+		fmt.str++;
+		return fmt;
 	}
 
 precision:
 	/* get the precision */
 	spec->precision = -1;
-	if (*fmt == '.') {
-		++fmt;
-		if (isdigit(*fmt)) {
-			spec->precision = skip_atoi(&fmt);
+	if (unlikely(*fmt.str == '.')) {
+		fmt.str++;
+		if (isdigit(*fmt.str)) {
+			spec->precision = skip_atoi(&fmt.str);
 			if (spec->precision < 0)
 				spec->precision = 0;
-		} else if (*fmt == '*') {
+		} else if (*fmt.str == '*') {
 			/* it's the next argument */
-			spec->type = FORMAT_TYPE_PRECISION;
-			return ++fmt - start;
+			fmt.state = FORMAT_STATE_PRECISION;
+			fmt.str++;
+			return fmt;
 		}
 	}
 
 qualifier:
-	/* get the conversion qualifier */
-	qualifier = 0;
-	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
-	    *fmt == 'z' || *fmt == 't') {
-		qualifier = *fmt++;
-		if (unlikely(qualifier == *fmt)) {
-			if (qualifier == 'l') {
-				qualifier = 'L';
-				++fmt;
-			} else if (qualifier == 'h') {
-				qualifier = 'H';
-				++fmt;
-			}
-		}
-	}
-
-	/* default base */
+	/* Set up default numeric format */
 	spec->base = 10;
-	switch (*fmt) {
-	case 'c':
-		spec->type = FORMAT_TYPE_CHAR;
-		return ++fmt - start;
-
-	case 's':
-		spec->type = FORMAT_TYPE_STR;
-		return ++fmt - start;
-
-	case 'p':
-		spec->type = FORMAT_TYPE_PTR;
-		return ++fmt - start;
-
-	case '%':
-		spec->type = FORMAT_TYPE_PERCENT_CHAR;
-		return ++fmt - start;
-
-	/* integer number formats - set up the flags and "break" */
-	case 'o':
-		spec->base = 8;
-		break;
-
-	case 'x':
-		spec->flags |= SMALL;
-		fallthrough;
-
-	case 'X':
-		spec->base = 16;
-		break;
+	fmt.state = FORMAT_STATE_NUM;
+	fmt.size = sizeof(int);
+	static const struct format_state {
+		unsigned char state;
+		unsigned char size;
+		unsigned char flags_or_double_size;
+		unsigned char base;
+	} lookup_state[256] = {
+		// Length
+		['l'] = { 0, sizeof(long), sizeof(long long) },
+		['L'] = { 0, sizeof(long long) },
+		['h'] = { 0, sizeof(short), sizeof(char) },
+		['H'] = { 0, sizeof(char) },	// Questionable historical
+		['z'] = { 0, sizeof(size_t) },
+		['t'] = { 0, sizeof(ptrdiff_t) },
+
+		// Non-numeric formats
+		['c'] = { FORMAT_STATE_CHAR },
+		['s'] = { FORMAT_STATE_STR },
+		['p'] = { FORMAT_STATE_PTR },
+		['%'] = { FORMAT_STATE_PERCENT_CHAR },
+
+		// Numerics
+		['o'] = { FORMAT_STATE_NUM, 0, 0, 8 },
+		['x'] = { FORMAT_STATE_NUM, 0, SMALL, 16 },
+		['X'] = { FORMAT_STATE_NUM, 0, 0, 16 },
+		['d'] = { FORMAT_STATE_NUM, 0, SIGN, 10 },
+		['i'] = { FORMAT_STATE_NUM, 0, SIGN, 10 },
+		['u'] = { FORMAT_STATE_NUM, 0, 0, 10, },
 
-	case 'd':
-	case 'i':
-		spec->flags |= SIGN;
-		break;
-	case 'u':
-		break;
-
-	case 'n':
 		/*
 		 * Since %n poses a greater security risk than
 		 * utility, treat it as any other invalid or
 		 * unsupported format specifier.
 		 */
-		fallthrough;
+	};
 
-	default:
-		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
-		spec->type = FORMAT_TYPE_INVALID;
-		return fmt - start;
-	}
-
-	if (qualifier == 'L')
-		spec->type = FORMAT_TYPE_LONG_LONG;
-	else if (qualifier == 'l') {
-		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
-		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
-	} else if (qualifier == 'z') {
-		spec->type = FORMAT_TYPE_SIZE_T;
-	} else if (qualifier == 't') {
-		spec->type = FORMAT_TYPE_PTRDIFF;
-	} else if (qualifier == 'H') {
-		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
-		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
-	} else if (qualifier == 'h') {
-		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
-		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
-	} else {
-		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
-		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
+	const struct format_state *p = lookup_state + (u8)*fmt.str;
+	if (p->size) {
+		fmt.size = p->size;
+		if (p->flags_or_double_size && fmt.str[0] == fmt.str[1]) {
+			fmt.size = p->flags_or_double_size;
+			fmt.str++;
+		}
+		fmt.str++;
+		p = lookup_state + *fmt.str;
+	}
+	if (p->state) {
+		if (p->base)
+			spec->base = p->base;
+		spec->flags |= p->flags_or_double_size;
+		fmt.state = p->state;
+		fmt.str++;
+		return fmt;
 	}
 
-	return ++fmt - start;
+	WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt.str);
+	fmt.state = FORMAT_STATE_INVALID;
+	return fmt;
 }
 
 static void
@@ -2747,11 +2713,27 @@ set_precision(struct printf_spec *spec, int prec)
 	}
 }
 
+/*
+ * Turn a 1/2/4-byte value into a 64-bit one for printing: truncate
+ * as necessary and deal with signedness.
+ *
+ * 'size' is the size of the value in bytes.
+ */
+static unsigned long long convert_num_spec(unsigned int val, int size, struct printf_spec spec)
+{
+	unsigned int shift = 32 - size*8;
+
+	val <<= shift;
+	if (!(spec.flags & SIGN))
+		return val >> shift;
+	return (int)val >> shift;
+}
+
 /**
  * vsnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
- * @fmt: The format string to use
+ * @fmt_str: The format string to use
  * @args: Arguments for the format string
  *
  * This function generally follows C99 vsnprintf, but has some
@@ -2775,11 +2757,14 @@ set_precision(struct printf_spec *spec, int prec)
  *
  * If you're not already dealing with a va_list consider using snprintf().
  */
-int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
+int vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args)
 {
-	unsigned long long num;
 	char *str, *end;
 	struct printf_spec spec = {0};
+	struct fmt fmt = {
+		.str = fmt_str,
+		.state = FORMAT_STATE_NONE,
+	};
 
 	/* Reject out-of-range values early.  Large positive sizes are
 	   used for unknown buffer sizes. */
@@ -2795,33 +2780,43 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 		size = end - buf;
 	}
 
-	while (*fmt) {
-		const char *old_fmt = fmt;
-		int read = format_decode(fmt, &spec);
+	while (*fmt.str) {
+		const char *old_fmt = fmt.str;
 
-		fmt += read;
+		fmt = format_decode(fmt, &spec);
 
-		switch (spec.type) {
-		case FORMAT_TYPE_NONE: {
-			int copy = read;
+		switch (fmt.state) {
+		case FORMAT_STATE_NONE: {
+			int read = fmt.str - old_fmt;
 			if (str < end) {
+				int copy = read;
 				if (copy > end - str)
 					copy = end - str;
 				memcpy(str, old_fmt, copy);
 			}
 			str += read;
-			break;
+			continue;
 		}
 
-		case FORMAT_TYPE_WIDTH:
+		case FORMAT_STATE_NUM: {
+			unsigned long long num;
+			if (fmt.size <= sizeof(int))
+				num = convert_num_spec(va_arg(args, int), fmt.size, spec);
+			else
+				num = va_arg(args, long long);
+			str = number(str, end, num, spec);
+			continue;
+		}
+
+		case FORMAT_STATE_WIDTH:
 			set_field_width(&spec, va_arg(args, int));
-			break;
+			continue;
 
-		case FORMAT_TYPE_PRECISION:
+		case FORMAT_STATE_PRECISION:
 			set_precision(&spec, va_arg(args, int));
-			break;
+			continue;
 
-		case FORMAT_TYPE_CHAR: {
+		case FORMAT_STATE_CHAR: {
 			char c;
 
 			if (!(spec.flags & LEFT)) {
@@ -2841,27 +2836,27 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 					*str = ' ';
 				++str;
 			}
-			break;
+			continue;
 		}
 
-		case FORMAT_TYPE_STR:
+		case FORMAT_STATE_STR:
 			str = string(str, end, va_arg(args, char *), spec);
-			break;
+			continue;
 
-		case FORMAT_TYPE_PTR:
-			str = pointer(fmt, str, end, va_arg(args, void *),
+		case FORMAT_STATE_PTR:
+			str = pointer(fmt.str, str, end, va_arg(args, void *),
 				      spec);
-			while (isalnum(*fmt))
-				fmt++;
-			break;
+			while (isalnum(*fmt.str))
+				fmt.str++;
+			continue;
 
-		case FORMAT_TYPE_PERCENT_CHAR:
+		case FORMAT_STATE_PERCENT_CHAR:
 			if (str < end)
 				*str = '%';
 			++str;
-			break;
+			continue;
 
-		case FORMAT_TYPE_INVALID:
+		default:
 			/*
 			 * Presumably the arguments passed gcc's type
 			 * checking, but there is no safe or sane way
@@ -2871,47 +2866,6 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 			 * sync.
 			 */
 			goto out;
-
-		default:
-			switch (spec.type) {
-			case FORMAT_TYPE_LONG_LONG:
-				num = va_arg(args, long long);
-				break;
-			case FORMAT_TYPE_ULONG:
-				num = va_arg(args, unsigned long);
-				break;
-			case FORMAT_TYPE_LONG:
-				num = va_arg(args, long);
-				break;
-			case FORMAT_TYPE_SIZE_T:
-				if (spec.flags & SIGN)
-					num = va_arg(args, ssize_t);
-				else
-					num = va_arg(args, size_t);
-				break;
-			case FORMAT_TYPE_PTRDIFF:
-				num = va_arg(args, ptrdiff_t);
-				break;
-			case FORMAT_TYPE_UBYTE:
-				num = (unsigned char) va_arg(args, int);
-				break;
-			case FORMAT_TYPE_BYTE:
-				num = (signed char) va_arg(args, int);
-				break;
-			case FORMAT_TYPE_USHORT:
-				num = (unsigned short) va_arg(args, int);
-				break;
-			case FORMAT_TYPE_SHORT:
-				num = (short) va_arg(args, int);
-				break;
-			case FORMAT_TYPE_INT:
-				num = (int) va_arg(args, int);
-				break;
-			default:
-				num = va_arg(args, unsigned int);
-			}
-
-			str = number(str, end, num, spec);
 		}
 	}
 
@@ -3067,7 +3021,7 @@ EXPORT_SYMBOL(sprintf);
  * vbin_printf - Parse a format string and place args' binary value in a buffer
  * @bin_buf: The buffer to place args' binary value
  * @size: The size of the buffer(by words(32bits), not characters)
- * @fmt: The format string to use
+ * @fmt_str: The format string to use
  * @args: Arguments for the format string
  *
  * The format follows C99 vsnprintf, except %n is ignored, and its argument
@@ -3080,8 +3034,12 @@ EXPORT_SYMBOL(sprintf);
  * If the return value is greater than @size, the resulting bin_buf is NOT
  * valid for bstr_printf().
  */
-int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
+int vbin_printf(u32 *bin_buf, size_t size, const char *fmt_str, va_list args)
 {
+	struct fmt fmt = {
+		.str = fmt_str,
+		.state = FORMAT_STATE_NONE,
+	};
 	struct printf_spec spec = {0};
 	char *str, *end;
 	int width;
@@ -3113,31 +3071,29 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
 	value;								\
 })
 
-	while (*fmt) {
-		int read = format_decode(fmt, &spec);
+	while (*fmt.str) {
+		fmt = format_decode(fmt, &spec);
 
-		fmt += read;
-
-		switch (spec.type) {
-		case FORMAT_TYPE_NONE:
-		case FORMAT_TYPE_PERCENT_CHAR:
+		switch (fmt.state) {
+		case FORMAT_STATE_NONE:
+		case FORMAT_STATE_PERCENT_CHAR:
 			break;
-		case FORMAT_TYPE_INVALID:
+		case FORMAT_STATE_INVALID:
 			goto out;
 
-		case FORMAT_TYPE_WIDTH:
-		case FORMAT_TYPE_PRECISION:
+		case FORMAT_STATE_WIDTH:
+		case FORMAT_STATE_PRECISION:
 			width = (int)save_arg(int);
 			/* Pointers may require the width */
-			if (*fmt == 'p')
+			if (*fmt.str == 'p')
 				set_field_width(&spec, width);
 			break;
 
-		case FORMAT_TYPE_CHAR:
+		case FORMAT_STATE_CHAR:
 			save_arg(char);
 			break;
 
-		case FORMAT_TYPE_STR: {
+		case FORMAT_STATE_STR: {
 			const char *save_str = va_arg(args, char *);
 			const char *err_msg;
 			size_t len;
@@ -3153,9 +3109,9 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
 			break;
 		}
 
-		case FORMAT_TYPE_PTR:
+		case FORMAT_STATE_PTR:
 			/* Dereferenced pointers must be done now */
-			switch (*fmt) {
+			switch (*fmt.str) {
 			/* Dereference of functions is still OK */
 			case 'S':
 			case 's':
@@ -3165,11 +3121,11 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
 				save_arg(void *);
 				break;
 			default:
-				if (!isalnum(*fmt)) {
+				if (!isalnum(*fmt.str)) {
 					save_arg(void *);
 					break;
 				}
-				str = pointer(fmt, str, end, va_arg(args, void *),
+				str = pointer(fmt.str, str, end, va_arg(args, void *),
 					      spec);
 				if (str + 1 < end)
 					*str++ = '\0';
@@ -3177,35 +3133,14 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
 					end[-1] = '\0'; /* Must be nul terminated */
 			}
 			/* skip all alphanumeric pointer suffixes */
-			while (isalnum(*fmt))
-				fmt++;
+			while (isalnum(*fmt.str))
+				fmt.str++;
 			break;
 
-		default:
-			switch (spec.type) {
-
-			case FORMAT_TYPE_LONG_LONG:
+		case FORMAT_STATE_NUM:
+			if (fmt.size > sizeof(int)) {
 				save_arg(long long);
-				break;
-			case FORMAT_TYPE_ULONG:
-			case FORMAT_TYPE_LONG:
-				save_arg(unsigned long);
-				break;
-			case FORMAT_TYPE_SIZE_T:
-				save_arg(size_t);
-				break;
-			case FORMAT_TYPE_PTRDIFF:
-				save_arg(ptrdiff_t);
-				break;
-			case FORMAT_TYPE_UBYTE:
-			case FORMAT_TYPE_BYTE:
-				save_arg(char);
-				break;
-			case FORMAT_TYPE_USHORT:
-			case FORMAT_TYPE_SHORT:
-				save_arg(short);
-				break;
-			default:
+			} else {
 				save_arg(int);
 			}
 		}
@@ -3221,7 +3156,7 @@ EXPORT_SYMBOL_GPL(vbin_printf);
  * bstr_printf - Format a string from binary arguments and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
- * @fmt: The format string to use
+ * @fmt_str: The format string to use
  * @bin_buf: Binary arguments for the format string
  *
  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
@@ -3239,8 +3174,12 @@ EXPORT_SYMBOL_GPL(vbin_printf);
  * return is greater than or equal to @size, the resulting
  * string is truncated.
  */
-int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
+int bstr_printf(char *buf, size_t size, const char *fmt_str, const u32 *bin_buf)
 {
+	struct fmt fmt = {
+		.str = fmt_str,
+		.state = FORMAT_STATE_NONE,
+	};
 	struct printf_spec spec = {0};
 	char *str, *end;
 	const char *args = (const char *)bin_buf;
@@ -3272,33 +3211,33 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 		size = end - buf;
 	}
 
-	while (*fmt) {
-		const char *old_fmt = fmt;
-		int read = format_decode(fmt, &spec);
-
-		fmt += read;
+	while (*fmt.str) {
+		const char *old_fmt = fmt.str;
+		unsigned long long num;
 
-		switch (spec.type) {
-		case FORMAT_TYPE_NONE: {
-			int copy = read;
+		fmt = format_decode(fmt, &spec);
+		switch (fmt.state) {
+		case FORMAT_STATE_NONE: {
+			int read = fmt.str - old_fmt;
 			if (str < end) {
+				int copy = read;
 				if (copy > end - str)
 					copy = end - str;
 				memcpy(str, old_fmt, copy);
 			}
 			str += read;
-			break;
+			continue;
 		}
 
-		case FORMAT_TYPE_WIDTH:
+		case FORMAT_STATE_WIDTH:
 			set_field_width(&spec, get_arg(int));
-			break;
+			continue;
 
-		case FORMAT_TYPE_PRECISION:
+		case FORMAT_STATE_PRECISION:
 			set_precision(&spec, get_arg(int));
-			break;
+			continue;
 
-		case FORMAT_TYPE_CHAR: {
+		case FORMAT_STATE_CHAR: {
 			char c;
 
 			if (!(spec.flags & LEFT)) {
@@ -3317,21 +3256,21 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 					*str = ' ';
 				++str;
 			}
-			break;
+			continue;
 		}
 
-		case FORMAT_TYPE_STR: {
+		case FORMAT_STATE_STR: {
 			const char *str_arg = args;
 			args += strlen(str_arg) + 1;
 			str = string(str, end, (char *)str_arg, spec);
-			break;
+			continue;
 		}
 
-		case FORMAT_TYPE_PTR: {
+		case FORMAT_STATE_PTR: {
 			bool process = false;
 			int copy, len;
 			/* Non function dereferences were already done */
-			switch (*fmt) {
+			switch (*fmt.str) {
 			case 'S':
 			case 's':
 			case 'x':
@@ -3340,7 +3279,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 				process = true;
 				break;
 			default:
-				if (!isalnum(*fmt)) {
+				if (!isalnum(*fmt.str)) {
 					process = true;
 					break;
 				}
@@ -3355,63 +3294,32 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 				}
 			}
 			if (process)
-				str = pointer(fmt, str, end, get_arg(void *), spec);
+				str = pointer(fmt.str, str, end, get_arg(void *), spec);
 
-			while (isalnum(*fmt))
-				fmt++;
-			break;
+			while (isalnum(*fmt.str))
+				fmt.str++;
+			continue;
 		}
 
-		case FORMAT_TYPE_PERCENT_CHAR:
+		case FORMAT_STATE_PERCENT_CHAR:
 			if (str < end)
 				*str = '%';
 			++str;
-			break;
+			continue;
 
-		case FORMAT_TYPE_INVALID:
+		case FORMAT_STATE_INVALID:
 			goto out;
 
-		default: {
-			unsigned long long num;
-
-			switch (spec.type) {
-
-			case FORMAT_TYPE_LONG_LONG:
+		case FORMAT_STATE_NUM:
+			if (fmt.size > sizeof(int)) {
 				num = get_arg(long long);
-				break;
-			case FORMAT_TYPE_ULONG:
-			case FORMAT_TYPE_LONG:
-				num = get_arg(unsigned long);
-				break;
-			case FORMAT_TYPE_SIZE_T:
-				num = get_arg(size_t);
-				break;
-			case FORMAT_TYPE_PTRDIFF:
-				num = get_arg(ptrdiff_t);
-				break;
-			case FORMAT_TYPE_UBYTE:
-				num = get_arg(unsigned char);
-				break;
-			case FORMAT_TYPE_BYTE:
-				num = get_arg(signed char);
-				break;
-			case FORMAT_TYPE_USHORT:
-				num = get_arg(unsigned short);
-				break;
-			case FORMAT_TYPE_SHORT:
-				num = get_arg(short);
-				break;
-			case FORMAT_TYPE_UINT:
-				num = get_arg(unsigned int);
-				break;
-			default:
-				num = get_arg(int);
+			} else {
+				num = convert_num_spec(get_arg(int), fmt.size, spec);
 			}
-
 			str = number(str, end, num, spec);
-		} /* default: */
-		} /* switch(spec.type) */
-	} /* while(*fmt) */
+			continue;
+		}
+	} /* while(*fmt.str) */
 
 out:
 	if (size > 0) {