1 files changed, 42 insertions, 16 deletions

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 244e54a2153b..16e7dc89f61d 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -19,18 +19,44 @@
 #include "line.h"
 #include "os.h"
 
-#ifdef CONFIG_NOCONFIG_CHAN
+/* XXX: could well be moved to somewhere else, if needed. */
+static int my_printf(const char * fmt, ...)
+        __attribute__ ((format (printf, 1, 2)));
+
+static int my_printf(const char * fmt, ...)
+{
+        /* Yes, can be called on atomic context.*/
+        char *buf = kmalloc(4096, GFP_ATOMIC);
+        va_list args;
+        int r;
+
+        if (!buf) {
+                /* We print directly fmt.
+                 * Yes, yes, yes, feel free to complain. */
+                r = strlen(fmt);
+        } else {
+                va_start(args, fmt);
+                r = vsprintf(buf, fmt, args);
+                va_end(args);
+                fmt = buf;
+        }
 
-/* The printk's here are wrong because we are complaining that there is no
- * output device, but printk is printing to that output device.  The user will
- * never see the error.  printf would be better, except it can't run on a
- * kernel stack because it will overflow it.
- * Use printk for now since that will avoid crashing.
- */
+        if (r)
+                r = os_write_file(1, fmt, r);
+        return r;
+
+}
+
+#ifdef CONFIG_NOCONFIG_CHAN
+/* Despite its name, there's no added trailing newline. */
+static int my_puts(const char * buf)
+{
+        return os_write_file(1, buf, strlen(buf));
+}
 
 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(NULL);
 }
@@ -38,27 +64,27 @@ static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 static int not_configged_open(int input, int output, int primary, void *data,
                               char **dev_out)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-ENODEV);
 }
 
 static void not_configged_close(int fd, void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
 }
 
 static int not_configged_read(int fd, char *c_out, void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-EIO);
 }
 
 static int not_configged_write(int fd, const char *buf, int len, void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-EIO);
 }
@@ -66,7 +92,7 @@ static int not_configged_write(int fd, const char *buf, int len, void *data)
 static int not_configged_console_write(int fd, const char *buf, int len,
                                        void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-EIO);
 }
@@ -74,14 +100,14 @@ static int not_configged_console_write(int fd, const char *buf, int len,
 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
                                      unsigned short *cols)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-ENODEV);
 }
 
 static void not_configged_free(void *data)
 {
-        printf(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
 }
 
@@ -457,7 +483,7 @@ static struct chan *parse_chan(char *str, int pri, int device,
                 }
         }
         if(ops == NULL){
-                printk(KERN_ERR "parse_chan couldn't parse \"%s\"\n", 
+                my_printf("parse_chan couldn't parse \"%s\"\n",
                        str);
                 return(NULL);
         }