1 files changed, 23 insertions, 54 deletions

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 7d4190e55654..4e7e3cfa21f9 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -19,44 +19,11 @@
 #include "line.h"
 #include "os.h"
 
-/* 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;
-        }
-
-        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)
+static void *not_configged_init(char *str, int device,
+                                const struct chan_opts *opts)
 {
-        return os_write_file(1, buf, strlen(buf));
-}
-
-static void *not_configged_init(char *str, int device, struct chan_opts *opts)
-{
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
         return NULL;
 }
@@ -64,34 +31,34 @@ 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)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
         return -ENODEV;
 }
 
 static void not_configged_close(int fd, void *data)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
 }
 
 static int not_configged_read(int fd, char *c_out, void *data)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("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)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
         return -EIO;
 }
 
 static int not_configged_console_write(int fd, const char *buf, int len)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
         return -EIO;
 }
@@ -99,14 +66,14 @@ 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)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
         return -ENODEV;
 }
 
 static void not_configged_free(void *data)
 {
-        my_puts("Using a channel type which is configured out of "
+        printk("Using a channel type which is configured out of "
                "UML\n");
 }
 
@@ -534,7 +501,7 @@ static const struct chan_type chan_table[] = {
 };
 
 static struct chan *parse_chan(struct line *line, char *str, int device,
-                               const struct chan_opts *opts)
+                               const struct chan_opts *opts, char **error_out)
 {
         const struct chan_type *entry;
         const struct chan_ops *ops;
@@ -553,19 +520,21 @@ static struct chan *parse_chan(struct line *line, char *str, int device,
                 }
         }
         if(ops == NULL){
-                my_printf("parse_chan couldn't parse \"%s\"\n",
-                       str);
+                *error_out = "No match for configured backends";
                 return NULL;
         }
-        if(ops->init == NULL)
-                return NULL;
+
         data = (*ops->init)(str, device, opts);
-        if(data == NULL)
+        if(data == NULL){
+                *error_out = "Configuration failed";
                 return NULL;
+        }
 
         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
-        if(chan == NULL)
+        if(chan == NULL){
+                *error_out = "Memory allocation failed";
                 return NULL;
+        }
         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
                                  .free_list     =
                                         LIST_HEAD_INIT(chan->free_list),
@@ -582,7 +551,7 @@ static struct chan *parse_chan(struct line *line, char *str, int device,
 }
 
 int parse_chan_pair(char *str, struct line *line, int device,
-                    const struct chan_opts *opts)
+                    const struct chan_opts *opts, char **error_out)
 {
         struct list_head *chans = &line->chan_list;
         struct chan *new, *chan;
@@ -599,14 +568,14 @@ int parse_chan_pair(char *str, struct line *line, int device,
                 in = str;
                 *out = '\0';
                 out++;
-                new = parse_chan(line, in, device, opts);
+                new = parse_chan(line, in, device, opts, error_out);
                 if(new == NULL)
                         return -1;
 
                 new->input = 1;
                 list_add(&new->list, chans);
 
-                new = parse_chan(line, out, device, opts);
+                new = parse_chan(line, out, device, opts, error_out);
                 if(new == NULL)
                         return -1;
 
@@ -614,7 +583,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
                 new->output = 1;
         }
         else {
-                new = parse_chan(line, str, device, opts);
+                new = parse_chan(line, str, device, opts, error_out);
                 if(new == NULL)
                         return -1;