diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2018-04-10 16:32:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 10:28:35 -0700 |
| commit | 3ea056c50476f877f8bceb560ab69871098cb3a9 (patch) | |
| tree | 2872525aab82ea6f4d2170e5371878d8739fd6bb /kernel/utsname.c | |
| parent | bc4f2f5469ac2a52affadc4c00c1276d76151a39 (diff) | |
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@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/utsname.c')
| -rw-r--r-- | kernel/utsname.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/kernel/utsname.c b/kernel/utsname.c index 913fe4336d2b..dcd6be1996fe 100644 --- a/kernel/utsname.c +++ b/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_ns(void) { 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_ns(void) /* * 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_ns(struct user_namespace *user_ns, 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_operations = { .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); +} |