apparmor: add kvzalloc to handle zeroing for kvmalloc

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>

3 files changed, 22 insertions, 8 deletions

diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index 40aedd9f73ea..1ba2ca56a6ef 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -15,6 +15,7 @@
 #ifndef __APPARMOR_H
 #define __APPARMOR_H
 
+#include <linux/slab.h>
 #include <linux/fs.h>
 
 #include "match.h"
@@ -64,9 +65,18 @@ extern int apparmor_initialized __initdata;
 /* fn's in lib */
 char *aa_split_fqname(char *args, char **ns_name);
 void aa_info_message(const char *str);
-void *kvmalloc(size_t size);
+void *__aa_kvmalloc(size_t size, gfp_t flags);
 void kvfree(void *buffer);
 
+static inline void *kvmalloc(size_t size)
+{
+        return __aa_kvmalloc(size, 0);
+}
+
+static inline void *kvzalloc(size_t size)
+{
+        return __aa_kvmalloc(size, __GFP_ZERO);
+}
 
 /**
  * aa_strneq - compare null terminated @str to a non null terminated substring
diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c
index 7430298116d6..d6e1f2148398 100644
--- a/security/apparmor/lib.c
+++ b/security/apparmor/lib.c
@@ -75,15 +75,16 @@ void aa_info_message(const char *str)
 }
 
 /**
- * kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
- * @size: size of allocation
+ * __aa_kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
+ * @size: how many bytes of memory are required
+ * @flags: the type of memory to allocate (see kmalloc).
  *
  * Return: allocated buffer or NULL if failed
  *
  * It is possible that policy being loaded from the user is larger than
  * what can be allocated by kmalloc, in those cases fall back to vmalloc.
  */
-void *kvmalloc(size_t size)
+void *__aa_kvmalloc(size_t size, gfp_t flags)
 {
         void *buffer = NULL;
 
@@ -92,14 +93,17 @@ void *kvmalloc(size_t size)
 
         /* do not attempt kmalloc if we need more than 16 pages at once */
         if (size <= (16*PAGE_SIZE))
-                buffer = kmalloc(size, GFP_NOIO | __GFP_NOWARN);
+                buffer = kmalloc(size, flags | GFP_NOIO | __GFP_NOWARN);
         if (!buffer) {
                 /* see kvfree for why size must be at least work_struct size
                  * when allocated via vmalloc
                  */
                 if (size < sizeof(struct work_struct))
                         size = sizeof(struct work_struct);
-                buffer = vmalloc(size);
+                if (flags & __GFP_ZERO)
+                        buffer = vzalloc(size);
+                else
+                        buffer = vmalloc(size);
         }
         return buffer;
 }
diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 90971a8c3789..dfd25a9c9a69 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -30,7 +30,7 @@
  *
  * Returns: pointer to table else NULL on failure
  *
- * NOTE: must be freed by kvfree (not kmalloc)
+ * NOTE: must be freed by kvfree (not kfree)
  */
 static struct table_header *unpack_table(char *blob, size_t bsize)
 {
@@ -57,7 +57,7 @@ static struct table_header *unpack_table(char *blob, size_t bsize)
         if (bsize < tsize)
                 goto out;
 
-        table = kvmalloc(tsize);
+        table = kvzalloc(tsize);
         if (table) {
                 *table = th;
                 if (th.td_flags == YYTD_DATA8)