1 files changed, 145 insertions, 107 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index ac3f9476b776..48ff9c36644d 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -383,13 +383,14 @@ 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;
+#define FIELD_WIDTH_MAX ((1 << 23) - 1)
+#define PRECISION_MAX ((1 << 15) - 1)
 
 static noinline_for_stack
 char *number(char *buf, char *end, unsigned long long num,
@@ -402,6 +403,10 @@ char *number(char *buf, char *end, unsigned long long num,
 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 	int i;
 	bool is_zero = num == 0LL;
+	int field_width = spec.field_width;
+	int precision = spec.precision;
+
+	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 */
@@ -413,20 +418,20 @@ char *number(char *buf, char *end, unsigned long long num,
 		if ((signed long long)num < 0) {
 			sign = '-';
 			num = -(signed long long)num;
-			spec.field_width--;
+			field_width--;
 		} else if (spec.flags & PLUS) {
 			sign = '+';
-			spec.field_width--;
+			field_width--;
 		} else if (spec.flags & SPACE) {
 			sign = ' ';
-			spec.field_width--;
+			field_width--;
 		}
 	}
 	if (need_pfx) {
 		if (spec.base == 16)
-			spec.field_width -= 2;
+			field_width -= 2;
 		else if (!is_zero)
-			spec.field_width--;
+			field_width--;
 	}
 
 	/* generate full string in tmp[], in reverse order */
@@ -448,12 +453,12 @@ char *number(char *buf, char *end, unsigned long long num,
 	}
 
 	/* printing 100 using %2d gives "100", not "00" */
-	if (i > spec.precision)
-		spec.precision = i;
+	if (i > precision)
+		precision = i;
 	/* leading space padding */
-	spec.field_width -= spec.precision;
+	field_width -= precision;
 	if (!(spec.flags & (ZEROPAD | LEFT))) {
-		while (--spec.field_width >= 0) {
+		while (--field_width >= 0) {
 			if (buf < end)
 				*buf = ' ';
 			++buf;
@@ -482,14 +487,14 @@ char *number(char *buf, char *end, unsigned long long num,
 	if (!(spec.flags & LEFT)) {
 		char c = ' ' + (spec.flags & ZEROPAD);
 		BUILD_BUG_ON(' ' + ZEROPAD != '0');
-		while (--spec.field_width >= 0) {
+		while (--field_width >= 0) {
 			if (buf < end)
 				*buf = c;
 			++buf;
 		}
 	}
 	/* hmm even more zero padding? */
-	while (i <= --spec.precision) {
+	while (i <= --precision) {
 		if (buf < end)
 			*buf = '0';
 		++buf;
@@ -501,7 +506,7 @@ char *number(char *buf, char *end, unsigned long long num,
 		++buf;
 	}
 	/* trailing space padding */
-	while (--spec.field_width >= 0) {
+	while (--field_width >= 0) {
 		if (buf < end)
 			*buf = ' ';
 		++buf;
@@ -511,37 +516,20 @@ char *number(char *buf, char *end, unsigned long long num,
 }
 
 static noinline_for_stack
-char *string(char *buf, char *end, const char *s, struct printf_spec spec)
+char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 {
-	int len, i;
-
-	if ((unsigned long)s < PAGE_SIZE)
-		s = "(null)";
+	struct printf_spec spec;
 
-	len = strnlen(s, spec.precision);
-
-	if (!(spec.flags & LEFT)) {
-		while (len < spec.field_width--) {
-			if (buf < end)
-				*buf = ' ';
-			++buf;
-		}
-	}
-	for (i = 0; i < len; ++i) {
-		if (buf < end)
-			*buf = *s;
-		++buf; ++s;
-	}
-	while (len < spec.field_width--) {
-		if (buf < end)
-			*buf = ' ';
-		++buf;
-	}
+	spec.type = FORMAT_TYPE_PTR;
+	spec.field_width = 2 + 2 * size;	/* 0x + hex */
+	spec.flags = SPECIAL | SMALL | ZEROPAD;
+	spec.base = 16;
+	spec.precision = -1;
 
-	return buf;
+	return number(buf, end, num, spec);
 }
 
-static void widen(char *buf, char *end, unsigned len, unsigned spaces)
+static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 {
 	size_t size;
 	if (buf >= end)	/* nowhere to put anything */
@@ -559,6 +547,56 @@ static void widen(char *buf, char *end, unsigned len, unsigned spaces)
 	memset(buf, ' ', spaces);
 }
 
+/*
+ * Handle field width padding for a string.
+ * @buf: current buffer position
+ * @n: length of string
+ * @end: end of output buffer
+ * @spec: for field width and flags
+ * Returns: new buffer position after padding.
+ */
+static noinline_for_stack
+char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
+{
+	unsigned spaces;
+
+	if (likely(n >= spec.field_width))
+		return buf;
+	/* we want to pad the sucker */
+	spaces = spec.field_width - n;
+	if (!(spec.flags & LEFT)) {
+		move_right(buf - n, end, n, spaces);
+		return buf + spaces;
+	}
+	while (spaces--) {
+		if (buf < end)
+			*buf = ' ';
+		++buf;
+	}
+	return buf;
+}
+
+static noinline_for_stack
+char *string(char *buf, char *end, const char *s, struct printf_spec spec)
+{
+	int len = 0;
+	size_t lim = spec.precision;
+
+	if ((unsigned long)s < PAGE_SIZE)
+		s = "(null)";
+
+	while (lim--) {
+		char c = *s++;
+		if (!c)
+			break;
+		if (buf < end)
+			*buf = c;
+		++buf;
+		++len;
+	}
+	return widen_string(buf, len, end, spec);
+}
+
 static noinline_for_stack
 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 		  const char *fmt)
@@ -600,20 +638,7 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
 			*buf = c;
 	}
 	rcu_read_unlock();
-	if (n < spec.field_width) {
-		/* we want to pad the sucker */
-		unsigned spaces = spec.field_width - n;
-		if (!(spec.flags & LEFT)) {
-			widen(buf - n, end, n, spaces);
-			return buf + spaces;
-		}
-		while (spaces--) {
-			if (buf < end)
-				*buf = ' ';
-			++buf;
-		}
-	}
-	return buf;
+	return widen_string(buf, n, end, spec);
 }
 
 #ifdef CONFIG_BLOCK
@@ -659,11 +684,7 @@ char *symbol_string(char *buf, char *end, void *ptr,
 
 	return string(buf, end, sym, spec);
 #else
-	spec.field_width = 2 * sizeof(void *);
-	spec.flags |= SPECIAL | SMALL | ZEROPAD;
-	spec.base = 16;
-
-	return number(buf, end, value, spec);
+	return special_hex_number(buf, end, value, sizeof(void *));
 #endif
 }
 
@@ -1324,40 +1345,45 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
 	return string(buf, end, uuid, spec);
 }
 
-static
-char *netdev_feature_string(char *buf, char *end, const u8 *addr,
-		      struct printf_spec spec)
+static noinline_for_stack
+char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
 {
-	spec.flags |= SPECIAL | SMALL | ZEROPAD;
-	if (spec.field_width == -1)
-		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
-	spec.base = 16;
+	unsigned long long num;
+	int size;
 
-	return number(buf, end, *(const netdev_features_t *)addr, spec);
+	switch (fmt[1]) {
+	case 'F':
+		num = *(const netdev_features_t *)addr;
+		size = sizeof(netdev_features_t);
+		break;
+	default:
+		num = (unsigned long)addr;
+		size = sizeof(unsigned long);
+		break;
+	}
+
+	return special_hex_number(buf, end, num, size);
 }
 
 static noinline_for_stack
-char *address_val(char *buf, char *end, const void *addr,
-		  struct printf_spec spec, const char *fmt)
+char *address_val(char *buf, char *end, const void *addr, const char *fmt)
 {
 	unsigned long long num;
-
-	spec.flags |= SPECIAL | SMALL | ZEROPAD;
-	spec.base = 16;
+	int size;
 
 	switch (fmt[1]) {
 	case 'd':
 		num = *(const dma_addr_t *)addr;
-		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
+		size = sizeof(dma_addr_t);
 		break;
 	case 'p':
 	default:
 		num = *(const phys_addr_t *)addr;
-		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
+		size = sizeof(phys_addr_t);
 		break;
 	}
 
-	return number(buf, end, num, spec);
+	return special_hex_number(buf, end, num, size);
 }
 
 static noinline_for_stack
@@ -1376,10 +1402,7 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
 #ifdef CONFIG_COMMON_CLK
 		return string(buf, end, __clk_get_name(clk), spec);
 #else
-		spec.base = 16;
-		spec.field_width = sizeof(unsigned long) * 2 + 2;
-		spec.flags |= SPECIAL | SMALL | ZEROPAD;
-		return number(buf, end, (unsigned long)clk, spec);
+		return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
 #endif
 	}
 }
@@ -1609,13 +1632,9 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 		break;
 
 	case 'N':
-		switch (fmt[1]) {
-		case 'F':
-			return netdev_feature_string(buf, end, ptr, spec);
-		}
-		break;
+		return netdev_bits(buf, end, ptr, fmt);
 	case 'a':
-		return address_val(buf, end, ptr, spec, fmt);
+		return address_val(buf, end, ptr, fmt);
 	case 'd':
 		return dentry_name(buf, end, ptr, spec, fmt);
 	case 'C':
@@ -1664,6 +1683,7 @@ 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) {
@@ -1746,16 +1766,16 @@ 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;
 			}
 		}
@@ -1812,19 +1832,19 @@ 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 {
@@ -1835,6 +1855,24 @@ qualifier:
 	return ++fmt - start;
 }
 
+static void
+set_field_width(struct printf_spec *spec, int width)
+{
+	spec->field_width = width;
+	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
+		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
+	}
+}
+
+static void
+set_precision(struct printf_spec *spec, int prec)
+{
+	spec->precision = prec;
+	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
+		spec->precision = clamp(prec, 0, PRECISION_MAX);
+	}
+}
+
 /**
  * vsnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
@@ -1902,11 +1940,11 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 		}
 
 		case FORMAT_TYPE_WIDTH:
-			spec.field_width = va_arg(args, int);
+			set_field_width(&spec, va_arg(args, int));
 			break;
 
 		case FORMAT_TYPE_PRECISION:
-			spec.precision = va_arg(args, int);
+			set_precision(&spec, va_arg(args, int));
 			break;
 
 		case FORMAT_TYPE_CHAR: {
@@ -2346,11 +2384,11 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 		}
 
 		case FORMAT_TYPE_WIDTH:
-			spec.field_width = get_arg(int);
+			set_field_width(&spec, get_arg(int));
 			break;
 
 		case FORMAT_TYPE_PRECISION:
-			spec.precision = get_arg(int);
+			set_precision(&spec, get_arg(int));
 			break;
 
 		case FORMAT_TYPE_CHAR: {