[PATCH] uml: stack consumption reduction

Fix some stack abuse in the sysrq t path.

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

2 files changed, 14 insertions, 5 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 79610b5..773a134 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -598,6 +598,11 @@ out:
 	mconsole_reply(req, err_msg, err, 0);
 }
 
+struct mconsole_output {
+	struct list_head list;
+	struct mc_request *req;
+};
+
 static DEFINE_SPINLOCK(console_lock);
 static LIST_HEAD(clients);
 static char console_buf[MCONSOLE_MAX_DATA];
@@ -622,10 +627,10 @@ static void console_write(struct console *console, const char *string,
 			return;
 
 		list_for_each(ele, &clients){
-			struct mconsole_entry *entry;
+			struct mconsole_output *entry;
 
-			entry = list_entry(ele, struct mconsole_entry, list);
-			mconsole_reply_len(&entry->request, console_buf,
+			entry = list_entry(ele, struct mconsole_output, list);
+			mconsole_reply_len(entry->req, console_buf,
 					   console_index, 0, 1);
 		}
 
@@ -649,10 +654,10 @@ late_initcall(mc_add_console);
 static void with_console(struct mc_request *req, void (*proc)(void *),
 			 void *arg)
 {
-	struct mconsole_entry entry;
+	struct mconsole_output entry;
 	unsigned long flags;
 
-	entry.request = *req;
+	entry.req = req;
 	list_add(&entry.list, &clients);
 	spin_lock_irqsave(&console_lock, flags);
 
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 5b2f5fe..17068eb 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -131,6 +131,10 @@ int mconsole_get_request(int fd, struct mc_request *req)
 int mconsole_reply_len(struct mc_request *req, const char *str, int total,
 		       int err, int more)
 {
+	/* XXX This is a stack consumption problem.  It'd be nice to
+	 * make it global and serialize access to it, but there are a
+	 * ton of callers to this function.
+	 */
 	struct mconsole_reply reply;
 	int len, n;