[LINUX] Import kasprintf patch from upstream.

kasprintf has been merged upstream with a slightly different protoype
to the one in Xen. Import this patch and fixup the Xen tree to fit.

Signed-off-by: Ian Campbell <ian.campbell@xensource.com>

3 files changed, 272 insertions, 0 deletions

diff --git a/patches/linux-2.6.16.32/kasprintf.patch b/patches/linux-2.6.16.32/kasprintf.patch
new file mode 100644
index 0000000000..03e8c07ccf
--- /dev/null
+++ b/patches/linux-2.6.16.32/kasprintf.patch
@@ -0,0 +1,59 @@
+commit e905914f96e11862b130dd229f73045dad9a34e8
+Author: Jeremy Fitzhardinge <jeremy@xensource.com>
+Date:   Sun Jun 25 05:49:17 2006 -0700
+
+    [PATCH] Implement kasprintf
+    
+    Implement kasprintf, a kernel version of asprintf.  This allocates the
+    memory required for the formatted string, including the trailing '\0'.
+    Returns NULL on allocation failure.
+    
+    Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
+    Signed-off-by: Chris Wright <chrisw@sous-sol.org>
+    Signed-off-by: Andrew Morton <akpm@osdl.org>
+    Signed-off-by: Linus Torvalds <torvalds@osdl.org>
+
+diff --git a/include/linux/kernel.h b/include/linux/kernel.h
+index 8c21aaa..3c5e4c2 100644
+--- a/include/linux/kernel.h
++++ b/include/linux/kernel.h
+@@ -117,6 +117,8 @@ extern int scnprintf(char * buf, size_t
+ 	__attribute__ ((format (printf, 3, 4)));
+ extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
+ 	__attribute__ ((format (printf, 3, 0)));
++extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
++	__attribute__ ((format (printf, 2, 3)));
+ 
+ extern int sscanf(const char *, const char *, ...)
+ 	__attribute__ ((format (scanf, 2, 3)));
+diff --git a/lib/vsprintf.c b/lib/vsprintf.c
+index f595947..797428a 100644
+--- a/lib/vsprintf.c
++++ b/lib/vsprintf.c
+@@ -849,3 +849,26 @@ int sscanf(const char * buf, const char
+ }
+ 
+ EXPORT_SYMBOL(sscanf);
++
++
++/* Simplified asprintf. */
++char *kasprintf(gfp_t gfp, const char *fmt, ...)
++{
++	va_list ap;
++	unsigned int len;
++	char *p;
++
++	va_start(ap, fmt);
++	len = vsnprintf(NULL, 0, fmt, ap);
++	va_end(ap);
++
++	p = kmalloc(len+1, gfp);
++	if (!p)
++		return NULL;
++	va_start(ap, fmt);
++	vsnprintf(p, len+1, fmt, ap);
++	va_end(ap);
++	return p;
++}
++
++EXPORT_SYMBOL(kasprintf);
diff --git a/patches/linux-2.6.16.32/series b/patches/linux-2.6.16.32/series
index ae8fbd2885..ef2c35842e 100644
--- a/patches/linux-2.6.16.32/series
+++ b/patches/linux-2.6.16.32/series
@@ -23,3 +23,5 @@ xenoprof-generic.patch
 x86-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
 x86_64-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
 x86-elfnote-as-preprocessor-macro.patch
+vsnprintf.patch
+kasprintf.patch
diff --git a/patches/linux-2.6.16.32/vsnprintf.patch b/patches/linux-2.6.16.32/vsnprintf.patch
new file mode 100644
index 0000000000..69a93fa5c5
--- /dev/null
+++ b/patches/linux-2.6.16.32/vsnprintf.patch
@@ -0,0 +1,211 @@
+commit f796937a062c7aeb44cd0e75e1586c8543634a7d
+Author: Jeremy Fitzhardinge <jeremy@xensource.com>
+Date:   Sun Jun 25 05:49:17 2006 -0700
+
+    [PATCH] Fix bounds check in vsnprintf, to allow for a 0 size and NULL buffer
+    
+    This change allows callers to use a 0-byte buffer and a NULL buffer pointer
+    with vsnprintf, so it can be used to determine how large the resulting
+    formatted string will be.
+    
+    Previously the code effectively treated a size of 0 as a size of 4G (on
+    32-bit systems), with other checks preventing it from actually trying to
+    emit the string - but the terminal \0 would still be written, which would
+    crash if the buffer is NULL.
+    
+    This change changes the boundary check so that 'end' points to the putative
+    location of the terminal '\0', which is only written if size > 0.
+    
+    vsnprintf still allows the buffer size to be set very large, to allow
+    unbounded buffer sizes (to implement sprintf, etc).
+    
+    [akpm@osdl.org: fix long-vs-longlong confusion]
+    Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
+    Signed-off-by: Chris Wright <chrisw@sous-sol.org>
+    Signed-off-by: Andrew Morton <akpm@osdl.org>
+    Signed-off-by: Linus Torvalds <torvalds@osdl.org>
+
+diff --git a/lib/vsprintf.c b/lib/vsprintf.c
+index b07db5c..f595947 100644
+--- a/lib/vsprintf.c
++++ b/lib/vsprintf.c
+@@ -187,49 +187,49 @@ static char * number(char * buf, char *
+ 	size -= precision;
+ 	if (!(type&(ZEROPAD+LEFT))) {
+ 		while(size-->0) {
+-			if (buf <= end)
++			if (buf < end)
+ 				*buf = ' ';
+ 			++buf;
+ 		}
+ 	}
+ 	if (sign) {
+-		if (buf <= end)
++		if (buf < end)
+ 			*buf = sign;
+ 		++buf;
+ 	}
+ 	if (type & SPECIAL) {
+ 		if (base==8) {
+-			if (buf <= end)
++			if (buf < end)
+ 				*buf = '0';
+ 			++buf;
+ 		} else if (base==16) {
+-			if (buf <= end)
++			if (buf < end)
+ 				*buf = '0';
+ 			++buf;
+-			if (buf <= end)
++			if (buf < end)
+ 				*buf = digits[33];
+ 			++buf;
+ 		}
+ 	}
+ 	if (!(type & LEFT)) {
+ 		while (size-- > 0) {
+-			if (buf <= end)
++			if (buf < end)
+ 				*buf = c;
+ 			++buf;
+ 		}
+ 	}
+ 	while (i < precision--) {
+-		if (buf <= end)
++		if (buf < end)
+ 			*buf = '0';
+ 		++buf;
+ 	}
+ 	while (i-- > 0) {
+-		if (buf <= end)
++		if (buf < end)
+ 			*buf = tmp[i];
+ 		++buf;
+ 	}
+ 	while (size-- > 0) {
+-		if (buf <= end)
++		if (buf < end)
+ 			*buf = ' ';
+ 		++buf;
+ 	}
+@@ -272,7 +272,8 @@ int vsnprintf(char *buf, size_t size, co
+ 				/* 'z' changed to 'Z' --davidm 1/25/99 */
+ 				/* 't' added for ptrdiff_t */
+ 
+-	/* Reject out-of-range values early */
++	/* Reject out-of-range values early.  Large positive sizes are
++	   used for unknown buffer sizes. */
+ 	if (unlikely((int) size < 0)) {
+ 		/* There can be only one.. */
+ 		static int warn = 1;
+@@ -282,16 +283,17 @@ int vsnprintf(char *buf, size_t size, co
+ 	}
+ 
+ 	str = buf;
+-	end = buf + size - 1;
++	end = buf + size;
+ 
+-	if (end < buf - 1) {
+-		end = ((void *) -1);
+-		size = end - buf + 1;
++	/* Make sure end is always >= buf */
++	if (end < buf) {
++		end = ((void *)-1);
++		size = end - buf;
+ 	}
+ 
+ 	for (; *fmt ; ++fmt) {
+ 		if (*fmt != '%') {
+-			if (str <= end)
++			if (str < end)
+ 				*str = *fmt;
+ 			++str;
+ 			continue;
+@@ -357,17 +359,17 @@ int vsnprintf(char *buf, size_t size, co
+ 			case 'c':
+ 				if (!(flags & LEFT)) {
+ 					while (--field_width > 0) {
+-						if (str <= end)
++						if (str < end)
+ 							*str = ' ';
+ 						++str;
+ 					}
+ 				}
+ 				c = (unsigned char) va_arg(args, int);
+-				if (str <= end)
++				if (str < end)
+ 					*str = c;
+ 				++str;
+ 				while (--field_width > 0) {
+-					if (str <= end)
++					if (str < end)
+ 						*str = ' ';
+ 					++str;
+ 				}
+@@ -382,18 +384,18 @@ int vsnprintf(char *buf, size_t size, co
+ 
+ 				if (!(flags & LEFT)) {
+ 					while (len < field_width--) {
+-						if (str <= end)
++						if (str < end)
+ 							*str = ' ';
+ 						++str;
+ 					}
+ 				}
+ 				for (i = 0; i < len; ++i) {
+-					if (str <= end)
++					if (str < end)
+ 						*str = *s;
+ 					++str; ++s;
+ 				}
+ 				while (len < field_width--) {
+-					if (str <= end)
++					if (str < end)
+ 						*str = ' ';
+ 					++str;
+ 				}
+@@ -426,7 +428,7 @@ int vsnprintf(char *buf, size_t size, co
+ 				continue;
+ 
+ 			case '%':
+-				if (str <= end)
++				if (str < end)
+ 					*str = '%';
+ 				++str;
+ 				continue;
+@@ -449,11 +451,11 @@ int vsnprintf(char *buf, size_t size, co
+ 				break;
+ 
+ 			default:
+-				if (str <= end)
++				if (str < end)
+ 					*str = '%';
+ 				++str;
+ 				if (*fmt) {
+-					if (str <= end)
++					if (str < end)
+ 						*str = *fmt;
+ 					++str;
+ 				} else {
+@@ -483,14 +485,13 @@ int vsnprintf(char *buf, size_t size, co
+ 		str = number(str, end, num, base,
+ 				field_width, precision, flags);
+ 	}
+-	if (str <= end)
+-		*str = '\0';
+-	else if (size > 0)
+-		/* don't write out a null byte if the buf size is zero */
+-		*end = '\0';
+-	/* the trailing null byte doesn't count towards the total
+-	* ++str;
+-	*/
++	if (size > 0) {
++		if (str < end)
++			*str = '\0';
++		else
++			*end = '\0';
++	}
++	/* the trailing null byte doesn't count towards the total */
+ 	return str-buf;
+ }
+