uml: sysrq and mconsole fixes

Fix the passing of printk output back to the mconsole client.  The existing
code was somewhat confused, accumulating output in a buffer, but writing it
out entirely whenever a new chunk was added.  This is fixed.

The earlier include cleanups caused linux/sysrq.h to not be included - this is
fixed by adding the include back, under CONFIG_MAGIC_SYSRQ.

CONFIG_MAGIC_SYSRQ is also defaulted to on in defconfig.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/defconfig b/arch/um/defconfig
index ed3196d..658f654 100644 (file)
--- a/arch/um/defconfig
+++ b/arch/um/defconfig
@@ -80,7 +80,7 @@ CONFIG_BINFMT_MISC=m
 # CONFIG_HOSTFS is not set
 # CONFIG_HPPFS is not set
 CONFIG_MCONSOLE=y
-# CONFIG_MAGIC_SYSRQ is not set
+CONFIG_MAGIC_SYSRQ=y
 CONFIG_NEST_LEVEL=0
 # CONFIG_HIGHMEM is not set
 CONFIG_KERNEL_STACK_ORDER=0

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 5f6dbb1..642bee2 100644 (file)
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -632,10 +632,9 @@ struct mconsole_output {
 static DEFINE_SPINLOCK(client_lock);
 static LIST_HEAD(clients);
 static char console_buf[MCONSOLE_MAX_DATA];
-static int console_index = 0;
 
 static void console_write(struct console *console, const char *string,
-                         unsigned len)
+                         unsigned int len)
 {
        struct list_head *ele;
        int n;
@@ -643,24 +642,18 @@ static void console_write(struct console *console, const char *string,
        if (list_empty(&clients))
                return;
 
-       while (1) {
-               n = min((size_t) len, ARRAY_SIZE(console_buf) - console_index);
-               strncpy(&console_buf[console_index], string, n);
-               console_index += n;
+       while (len > 0) {
+               n = min((size_t) len, ARRAY_SIZE(console_buf));
+               strncpy(console_buf, string, n);
                string += n;
                len -= n;
-               if (len == 0)
-                       return;
 
                list_for_each(ele, &clients) {
                        struct mconsole_output *entry;
 
                        entry = list_entry(ele, struct mconsole_output, list);
-                       mconsole_reply_len(entry->req, console_buf,
-                                          console_index, 0, 1);
+                       mconsole_reply_len(entry->req, console_buf, n, 0, 1);
                }
-
-               console_index = 0;
        }
 }
 
@@ -690,8 +683,7 @@ static void with_console(struct mc_request *req, void (*proc)(void *),
 
        (*proc)(arg);
 
-       mconsole_reply_len(req, console_buf, console_index, 0, 0);
-       console_index = 0;
+       mconsole_reply_len(req, "", 0, 0, 0);
 
        spin_lock_irqsave(&client_lock, flags);
        list_del(&entry.list);
@@ -699,6 +691,9 @@ static void with_console(struct mc_request *req, void (*proc)(void *),
 }
 
 #ifdef CONFIG_MAGIC_SYSRQ
+
+#include <linux/sysrq.h>
+
 static void sysrq_proc(void *arg)
 {
        char *op = arg;