seq_file: allocate seq_file from kmem_cache
For fine-grained debugging and usercopy protection.
Link: http://lkml.kernel.org/r/20180310085027.GA17121@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 0677e89..3cb3405 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -6,6 +6,7 @@
* initial implementation -- AV, Oct 2001.
*/
+#include <linux/cache.h>
#include <linux/fs.h>
#include <linux/export.h>
#include <linux/seq_file.h>
@@ -19,6 +20,8 @@
#include <linux/uaccess.h>
#include <asm/page.h>
+static struct kmem_cache *seq_file_cache __ro_after_init;
+
static void seq_set_overflow(struct seq_file *m)
{
m->count = m->size;
@@ -51,7 +54,7 @@
WARN_ON(file->private_data);
- p = kzalloc(sizeof(*p), GFP_KERNEL);
+ p = kmem_cache_zalloc(seq_file_cache, GFP_KERNEL);
if (!p)
return -ENOMEM;
@@ -366,7 +369,7 @@
{
struct seq_file *m = file->private_data;
kvfree(m->buf);
- kfree(m);
+ kmem_cache_free(seq_file_cache, m);
return 0;
}
EXPORT_SYMBOL(seq_release);
@@ -1106,3 +1109,8 @@
return NULL;
}
EXPORT_SYMBOL(seq_hlist_next_percpu);
+
+void __init seq_file_init(void)
+{
+ seq_file_cache = KMEM_CACHE(seq_file, SLAB_PANIC);
+}
