Driver core: fix show_uevent from taking up way too much stack

Declaring an array of PAGE_SIZE does bad things for people running with
4k stacks...

Thanks to Tilman Schmidt for tracking this down.

Cc: Tilman Schmidt <tilman@imap.cc>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 8aa090da1cd7..59d9816c332e 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -252,7 +252,7 @@ static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
         struct kobject *top_kobj;
         struct kset *kset;
         char *envp[32];
-        char data[PAGE_SIZE];
+        char *data = NULL;
         char *pos;
         int i;
         size_t count = 0;
@@ -276,6 +276,10 @@ static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
                 if (!kset->uevent_ops->filter(kset, &dev->kobj))
                         goto out;
 
+        data = (char *)get_zeroed_page(GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
         /* let the kset specific function add its keys */
         pos = data;
         retval = kset->uevent_ops->uevent(kset, &dev->kobj,
@@ -290,6 +294,7 @@ static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
                 count += sprintf(pos, "%s\n", envp[i]);
         }
 out:
+        free_page((unsigned long)data);
         return count;
 }