[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>

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 79610b5..773a134 100644 (file)
--- 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 (file)
--- 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;