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authorAlexey Dobriyan <adobriyan@gmail.com>2018-04-10 16:34:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-11 10:28:36 -0700
commit0965232035cfa59a64d197cf8a8ee0bc407bb3e4 (patch)
treef6c65bb356de0d962666185d7d4435b9afe76861
parent9ad553abe66f8be3f4755e9fa0a6ba137ce76341 (diff)
downloadlinux-stericsson-0965232035cfa59a64d197cf8a8ee0bc407bb3e4.tar.gz
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>
-rw-r--r--fs/seq_file.c12
-rw-r--r--include/linux/seq_file.h1
-rw-r--r--init/main.c1
3 files changed, 12 insertions, 2 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 0677e89f3c6f..3cb340583074 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 @@ int seq_open(struct file *file, const struct seq_operations *op)
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 @@ int seq_release(struct inode *inode, struct file *file)
{
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 @@ seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head,
return NULL;
}
EXPORT_SYMBOL(seq_hlist_next_percpu);
+
+void __init seq_file_init(void)
+{
+ seq_file_cache = KMEM_CACHE(seq_file, SLAB_PANIC);
+}
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 23d6a92cea9f..a121982af0f5 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -240,4 +240,5 @@ extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *hea
extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
+void seq_file_init(void);
#endif
diff --git a/init/main.c b/init/main.c
index 50359a3162d0..b795aa341a3a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -715,6 +715,7 @@ asmlinkage __visible void __init start_kernel(void)
vfs_caches_init();
pagecache_init();
signals_init();
+ seq_file_init();
proc_root_init();
nsfs_init();
cpuset_init();