vsprintf.c: use noinline_for_stack

Mark static functions with noinline_for_stack

Before:

  akpm:/usr/src/25> objdump -d lib/vsprintf.o | perl scripts/checkstack.pl
  0x00000e82 pointer [vsprintf.o]:                        344
  0x0000198c pointer [vsprintf.o]:                        344
  0x000025d6 scnprintf [vsprintf.o]:                      216
  0x00002648 scnprintf [vsprintf.o]:                      216
  0x00002565 snprintf [vsprintf.o]:                       208
  0x0000267c sprintf [vsprintf.o]:                        208
  0x000030a3 bprintf [vsprintf.o]:                        208
  0x00003b1e sscanf [vsprintf.o]:                         208
  0x00000608 number [vsprintf.o]:                         136
  0x00000937 number [vsprintf.o]:                         136

After:

  akpm:/usr/src/25> objdump -d lib/vsprintf.o | perl scripts/checkstack.pl
  0x00000a7c symbol_string [vsprintf.o]:                  248
  0x00000ae8 symbol_string [vsprintf.o]:                  248
  0x00002310 scnprintf [vsprintf.o]:                      216
  0x00002382 scnprintf [vsprintf.o]:                      216
  0x0000229f snprintf [vsprintf.o]:                       208
  0x000023b6 sprintf [vsprintf.o]:                        208
  0x00002ddd bprintf [vsprintf.o]:                        208
  0x00003858 sscanf [vsprintf.o]:                         208
  0x00000625 number [vsprintf.o]:                         136
  0x00000954 number [vsprintf.o]:                         136
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/vsprintf.c

@@ -267,7 +267,8 @@ int strict_strtoll(const char *cp, unsigned int base, long long *res)
 }
 EXPORT_SYMBOL(strict_strtoll);
 
-static int skip_atoi(const char **s)
+static noinline_for_stack
+int skip_atoi(const char **s)
 {
 	int i = 0;
 
@@ -287,7 +288,8 @@ static int skip_atoi(const char **s)
 /* Formats correctly any integer in [0,99999].
  * Outputs from one to five digits depending on input.
  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
-static char *put_dec_trunc(char *buf, unsigned q)
+static noinline_for_stack
+char *put_dec_trunc(char *buf, unsigned q)
 {
 	unsigned d3, d2, d1, d0;
 	d1 = (q>>4) & 0xf;
@@ -324,7 +326,8 @@ static char *put_dec_trunc(char *buf, unsigned q)
 	return buf;
 }
 /* Same with if's removed. Always emits five digits */
-static char *put_dec_full(char *buf, unsigned q)
+static noinline_for_stack
+char *put_dec_full(char *buf, unsigned q)
 {
 	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 	/* but anyway, gcc produces better code with full-sized ints */
@@ -366,7 +369,8 @@ static char *put_dec_full(char *buf, unsigned q)
 	return buf;
 }
 /* No inlining helps gcc to use registers better */
-static noinline char *put_dec(char *buf, unsigned long long num)
+static noinline_for_stack
+char *put_dec(char *buf, unsigned long long num)
 {
 	while (1) {
 		unsigned rem;
@@ -417,8 +421,9 @@ struct printf_spec {
 	s16	precision;	/* # of digits/chars */
 };
 
-static char *number(char *buf, char *end, unsigned long long num,
-			struct printf_spec spec)
+static noinline_for_stack
+char *number(char *buf, char *end, unsigned long long num,
+	     struct printf_spec spec)
 {
 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
@@ -537,7 +542,8 @@ static char *number(char *buf, char *end, unsigned long long num,
 	return buf;
 }
 
-static char *string(char *buf, char *end, const char *s, struct printf_spec spec)
+static noinline_for_stack
+char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 {
 	int len, i;
 
@@ -567,8 +573,9 @@ static char *string(char *buf, char *end, const char *s, struct printf_spec spec
 	return buf;
 }
 
-static char *symbol_string(char *buf, char *end, void *ptr,
-				struct printf_spec spec, char ext)
+static noinline_for_stack
+char *symbol_string(char *buf, char *end, void *ptr,
+		    struct printf_spec spec, char ext)
 {
 	unsigned long value = (unsigned long) ptr;
 #ifdef CONFIG_KALLSYMS
@@ -588,8 +595,9 @@ static char *symbol_string(char *buf, char *end, void *ptr,
 #endif
 }
 
-static char *resource_string(char *buf, char *end, struct resource *res,
-				struct printf_spec spec, const char *fmt)
+static noinline_for_stack
+char *resource_string(char *buf, char *end, struct resource *res,
+		      struct printf_spec spec, const char *fmt)
 {
 #ifndef IO_RSRC_PRINTK_SIZE
 #define IO_RSRC_PRINTK_SIZE	6
@@ -690,8 +698,9 @@ static char *resource_string(char *buf, char *end, struct resource *res,
 	return string(buf, end, sym, spec);
 }
 
-static char *mac_address_string(char *buf, char *end, u8 *addr,
-				struct printf_spec spec, const char *fmt)
+static noinline_for_stack
+char *mac_address_string(char *buf, char *end, u8 *addr,
+			 struct printf_spec spec, const char *fmt)
 {
 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 	char *p = mac_addr;
@@ -714,7 +723,8 @@ static char *mac_address_string(char *buf, char *end, u8 *addr,
 	return string(buf, end, mac_addr, spec);
 }
 
-static char *ip4_string(char *p, const u8 *addr, const char *fmt)
+static noinline_for_stack
+char *ip4_string(char *p, const u8 *addr, const char *fmt)
 {
 	int i;
 	bool leading_zeros = (fmt[0] == 'i');
@@ -763,7 +773,8 @@ static char *ip4_string(char *p, const u8 *addr, const char *fmt)
 	return p;
 }
 
-static char *ip6_compressed_string(char *p, const char *addr)
+static noinline_for_stack
+char *ip6_compressed_string(char *p, const char *addr)
 {
 	int i, j, range;
 	unsigned char zerolength[8];
@@ -843,7 +854,8 @@ static char *ip6_compressed_string(char *p, const char *addr)
 	return p;
 }
 
-static char *ip6_string(char *p, const char *addr, const char *fmt)
+static noinline_for_stack
+char *ip6_string(char *p, const char *addr, const char *fmt)
 {
 	int i;
 
@@ -858,8 +870,9 @@ static char *ip6_string(char *p, const char *addr, const char *fmt)
 	return p;
 }
 
-static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
-			     struct printf_spec spec, const char *fmt)
+static noinline_for_stack
+char *ip6_addr_string(char *buf, char *end, const u8 *addr,
+		      struct printf_spec spec, const char *fmt)
 {
 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 
@@ -871,8 +884,9 @@ static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 	return string(buf, end, ip6_addr, spec);
 }
 
-static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
-			     struct printf_spec spec, const char *fmt)
+static noinline_for_stack
+char *ip4_addr_string(char *buf, char *end, const u8 *addr,
+		      struct printf_spec spec, const char *fmt)
 {
 	char ip4_addr[sizeof("255.255.255.255")];
 
@@ -881,8 +895,9 @@ static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 	return string(buf, end, ip4_addr, spec);
 }
 
-static char *uuid_string(char *buf, char *end, const u8 *addr,
-			 struct printf_spec spec, const char *fmt)
+static noinline_for_stack
+char *uuid_string(char *buf, char *end, const u8 *addr,
+		  struct printf_spec spec, const char *fmt)
 {
 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 	char *p = uuid;
@@ -970,8 +985,9 @@ static char *uuid_string(char *buf, char *end, const u8 *addr,
  * function pointers are really function descriptors, which contain a
  * pointer to the real address.
  */
-static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
-			struct printf_spec spec)
+static noinline_for_stack
+char *pointer(const char *fmt, char *buf, char *end, void *ptr,
+	      struct printf_spec spec)
 {
 	if (!ptr)
 		return string(buf, end, "(null)", spec);
@@ -1040,7 +1056,8 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
  * @precision: precision of a number
  * @qualifier: qualifier of a number (long, size_t, ...)
  */
-static int format_decode(const char *fmt, struct printf_spec *spec)
+static noinline_for_stack
+int format_decode(const char *fmt, struct printf_spec *spec)
 {
 	const char *start = fmt;