[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 8c21aaa248b4ee1917340283846c6bdc8651ed6c..3c5e4c2e517dd8aa867336c2bc70c560f510f556 100644 (file)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -117,6 +117,8 @@ extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
        __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 f5959476e53d8e814efda819f684373c85d305af..797428afd1114f3dc1ad3c239917b9f04ceccd55 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -849,3 +849,26 @@ int sscanf(const char * buf, const char * fmt, ...)
 }
 
 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);