2004-09-08 Neal H. Walfield <neal@cs.uml.edu>

* linux/dev/kernel/printk.c: Include <kern/assert.h>.
	(printk): Use vsnprintf, not linux_vsprintf to avoid buffer
	overruns.

	* kern/printf.c (struct vsnprintf_cookie): New structure.
	(snputc): New function.
	(vsnprintf): Likewise.

3 files changed, 41 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index e6a7080..7772448 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2004-09-08  Neal H. Walfield  <neal@cs.uml.edu>
+
+	* linux/dev/kernel/printk.c: Include <kern/assert.h>.
+	(printk): Use vsnprintf, not linux_vsprintf to avoid buffer
+	overruns.
+
+	* kern/printf.c (struct vsnprintf_cookie): New structure.
+	(snputc): New function.
+	(vsnprintf): Likewise.
+
 2004-11-22  Guillem Jover  <guillem@hadrons.org>
 
 	* bogus/mach_assert.h: Change #ifdef DEBUG to #ifndef NDEBUG
diff --git a/kern/printf.c b/kern/printf.c
index 85e6278..e6478ae 100644
--- a/kern/printf.c
+++ b/kern/printf.c
@@ -579,6 +579,34 @@ sprintf(char *buf, const char *fmt, ...)
 	return (buf - start);
 }
 
+struct vsnprintf_cookie
+{
+  char *buf;
+  int index;
+  int max_len;
+};
+
+static void
+snputc(char c, vm_offset_t arg)
+{
+  struct vsnprintf_cookie *cookie = (void *) arg;
+
+  if (cookie->index < cookie->max_len)
+    cookie->buf[cookie->index ++] = c;
+}
+
+int
+vsnprintf(char *buf, int size, const char *fmt, va_list args)
+{
+  struct vsnprintf_cookie cookie
+    = { .buf = buf, .index = 0, .max_len = size };
+
+  _doprnt (fmt, &args, snputc, 16, (vm_offset_t)&cookie);
+  cookie.buf[cookie.index] = '\0';
+
+  return cookie.index;
+}
+
 
 void safe_gets(str, maxlen)
 	char *str;
diff --git a/linux/dev/kernel/printk.c b/linux/dev/kernel/printk.c
index 2ff52d1..9dc86cb 100644
--- a/linux/dev/kernel/printk.c
+++ b/linux/dev/kernel/printk.c
@@ -26,6 +26,7 @@
 #define MACH_INCLUDE
 #include <stdarg.h>
 #include <asm/system.h>
+#include <kern/assert.h>
 
 static char buf[2048];
 
@@ -40,14 +41,14 @@ printk (char *fmt, ...)
   va_list args;
   int n, flags;
   extern void cnputc ();
-  extern int linux_vsprintf (char *buf, char *fmt,...);
   char *p, *msg, *buf_end;
   static int msg_level = -1;
   
   save_flags (flags);
   cli ();
   va_start (args, fmt);
-  n = linux_vsprintf (buf + 3, fmt, args);
+  n = vsnprintf (buf + 3, sizeof (buf) - 3, fmt, args);
+  assert (n <= sizeof (buf) - 3);
   buf_end = buf + 3 + n;
   va_end (args);
   for (p = buf + 3; p < buf_end; p++)