+ uts-create-struct-uts_namespace-from-kmem_cache.patch added to -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** 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 <serue@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

--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux