[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 79610b5ce67e..773a134e7fdb 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 5b2f5fe9e426..17068eb746c0 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;