The patch titled
Subject: uts: create "struct uts_namespace" from kmem_cache
has been added to the -mm tree. Its filename is
uts-create-struct-uts_namespace-from-kmem_cache.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/uts-create-struct-uts_namespace-from-kmem_cache.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/uts-create-struct-uts_namespace-from-kmem_cache.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: uts: create "struct uts_namespace" from kmem_cache
So "struct uts_namespace" can enjoy fine-grained SLAB debugging and
usercopy protection.
I'd prefer shorter name "utsns" but there is "user_namespace" already.
Link: http://lkml.kernel.org/r/20180228215158.GA23146@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Serge Hallyn <serge@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/utsname.h | 6 ++++++
init/main.c | 2 ++
kernel/utsname.c | 20 ++++++++++++++++----
3 files changed, 24 insertions(+), 4 deletions(-)
diff -puN include/linux/utsname.h~uts-create-struct-uts_namespace-from-kmem_cache include/linux/utsname.h
--- a/include/linux/utsname.h~uts-create-struct-uts_namespace-from-kmem_cache
+++ a/include/linux/utsname.h
@@ -44,6 +44,8 @@ static inline void put_uts_ns(struct uts
{
kref_put(&ns->kref, free_uts_ns);
}
+
+void uts_ns_init(void);
#else
static inline void get_uts_ns(struct uts_namespace *ns)
{
@@ -61,6 +63,10 @@ static inline struct uts_namespace *copy
return old_ns;
}
+
+static inline void uts_ns_init(void)
+{
+}
#endif
#ifdef CONFIG_PROC_SYSCTL
diff -puN init/main.c~uts-create-struct-uts_namespace-from-kmem_cache init/main.c
--- a/init/main.c~uts-create-struct-uts_namespace-from-kmem_cache
+++ a/init/main.c
@@ -51,6 +51,7 @@
#include <linux/taskstats_kern.h>
#include <linux/delayacct.h>
#include <linux/unistd.h>
+#include <linux/utsname.h>
#include <linux/rmap.h>
#include <linux/mempolicy.h>
#include <linux/key.h>
@@ -689,6 +690,7 @@ asmlinkage __visible void __init start_k
cred_init();
fork_init();
proc_caches_init();
+ uts_ns_init();
buffer_init();
key_init();
security_init();
diff -puN kernel/utsname.c~uts-create-struct-uts_namespace-from-kmem_cache kernel/utsname.c
--- a/kernel/utsname.c~uts-create-struct-uts_namespace-from-kmem_cache
+++ a/kernel/utsname.c
@@ -19,6 +19,8 @@
#include <linux/proc_ns.h>
#include <linux/sched/task.h>
+static struct kmem_cache *uts_ns_cache __ro_after_init;
+
static struct ucounts *inc_uts_namespaces(struct user_namespace *ns)
{
return inc_ucount(ns, current_euid(), UCOUNT_UTS_NAMESPACES);
@@ -33,7 +35,7 @@ static struct uts_namespace *create_uts_
{
struct uts_namespace *uts_ns;
- uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
+ uts_ns = kmem_cache_alloc(uts_ns_cache, GFP_KERNEL);
if (uts_ns)
kref_init(&uts_ns->kref);
return uts_ns;
@@ -42,7 +44,7 @@ static struct uts_namespace *create_uts_
/*
* Clone a new ns copying an original utsname, setting refcount to 1
* @old_ns: namespace to clone
- * Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise
+ * Return ERR_PTR(-ENOMEM) on error (failure to allocate), new ns otherwise
*/
static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
struct uts_namespace *old_ns)
@@ -75,7 +77,7 @@ static struct uts_namespace *clone_uts_n
return ns;
fail_free:
- kfree(ns);
+ kmem_cache_free(uts_ns_cache, ns);
fail_dec:
dec_uts_namespaces(ucounts);
fail:
@@ -113,7 +115,7 @@ void free_uts_ns(struct kref *kref)
dec_uts_namespaces(ns->ucounts);
put_user_ns(ns->user_ns);
ns_free_inum(&ns->ns);
- kfree(ns);
+ kmem_cache_free(uts_ns_cache, ns);
}
static inline struct uts_namespace *to_uts_ns(struct ns_common *ns)
@@ -169,3 +171,13 @@ const struct proc_ns_operations utsns_op
.install = utsns_install,
.owner = utsns_owner,
};
+
+void __init uts_ns_init(void)
+{
+ uts_ns_cache = kmem_cache_create_usercopy(
+ "uts_namespace", sizeof(struct uts_namespace), 0,
+ SLAB_PANIC|SLAB_ACCOUNT,
+ offsetof(struct uts_namespace, name),
+ sizeof_field(struct uts_namespace, name),
+ NULL);
+}
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
proc-do-less-stuff-under-pde_unload_lock.patch
proc-move-proc-sysvipc-creation-to-where-it-belongs.patch
proc-faster-open-close-of-files-without-release-hook.patch
proc-randomize-struct-pde_opener.patch
proc-move-struct-pde_opener-to-kmem-cache.patch
proc-account-struct-pde_opener.patch
proc-check-permissions-earlier-for-proc-wchan.patch
proc-use-set_puts-at-proc-wchan.patch
uts-create-struct-uts_namespace-from-kmem_cache.patch
seq_file-delete-small-value-optimization.patch
--
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