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>

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 8aa090d..59d9816 100644 (file)
--- 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;
 }