* Re: PATCH -mm] fix create_new_namespaces() return value
2007-06-11 16:22 ` Badari Pulavarty
@ 2007-06-12 7:49 ` Cedric Le Goater
2007-06-12 12:19 ` Cedric Le Goater
1 sibling, 0 replies; 4+ messages in thread
From: Cedric Le Goater @ 2007-06-12 7:49 UTC (permalink / raw)
To: Badari Pulavarty
Cc: Linux Kernel Mailing List, Andrew Morton, Pavel Emelianov,
Herbert Poetzl, Eric W. Biederman, Serge E. Hallyn,
Linux Containers
Badari Pulavarty wrote:
>
>
> Cedric Le Goater wrote:
>
>> The following patch modifies create_new_namespaces() to also use the
>> errors returned by the copy_*_ns routines and not to systematically
>> return ENOMEM.
>>
>
> In my initial version, I did same. It doesn't work :(
>
> copy_*_ns() routines doesn't return any errors. All they return is NULL
> in case of a
> failure + with the exception of copy_mnt_ns, there are no other failure
> cases.
mnt ant uts namespaces return NULL right but this is not true for ipc namespace
which returns -ENOMEM. user namespace returns -EINVAL if CONFIG_USER_NS is not
selected. I expect pid namespace to do same and net namespace to do even more.
> So, there is no way to find out why the copy_*_ns() routines failed from
> create_new_namespaces().
> If you really really want to do this, change all copy_*_ns() routines to
> returns meaningful errors instead of NULL.
I will certainly do and change mnt ant uts namespaces to return -ENOMEM but
we will still require the patch below.
>> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
>> Cc: Serge E. Hallyn <serue@us.ibm.com>
>> Cc: Badari Pulavarty <pbadari@us.ibm.com>
>> Cc: Pavel Emelianov <xemul@openvz.org>
>> Cc: Herbert Poetzl <herbert@13thfloor.at>
>> Cc: Eric W. Biederman <ebiederm@xmission.com>
>> ---
>> kernel/nsproxy.c | 23 +++++++++++++++++------
>> 1 file changed, 17 insertions(+), 6 deletions(-)
>>
>> Index: 2.6.22-rc4-mm2/kernel/nsproxy.c
>> ===================================================================
>> --- 2.6.22-rc4-mm2.orig/kernel/nsproxy.c
>> +++ 2.6.22-rc4-mm2/kernel/nsproxy.c
>> @@ -58,30 +58,41 @@ static struct nsproxy *create_new_namesp
>> struct fs_struct *new_fs)
>> {
>> struct nsproxy *new_nsp;
>> + int err;
>>
>> new_nsp = clone_nsproxy(tsk->nsproxy);
>> if (!new_nsp)
>> return ERR_PTR(-ENOMEM);
>>
>> new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
>> - if (IS_ERR(new_nsp->mnt_ns))
>> + if (IS_ERR(new_nsp->mnt_ns)) {
>> + err = PTR_ERR(new_nsp->mnt_ns);
>> goto out_ns;
>> + }
>>
>> new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
>> - if (IS_ERR(new_nsp->uts_ns))
>> + if (IS_ERR(new_nsp->uts_ns)) {
>> + err = PTR_ERR(new_nsp->uts_ns);
>> goto out_uts;
>> + }
>>
>> new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
>> - if (IS_ERR(new_nsp->ipc_ns))
>> + if (IS_ERR(new_nsp->ipc_ns)) {
>> + err = PTR_ERR(new_nsp->ipc_ns);
>> goto out_ipc;
>> + }
>>
>> new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
>> - if (IS_ERR(new_nsp->pid_ns))
>> + if (IS_ERR(new_nsp->pid_ns)) {
>> + err = PTR_ERR(new_nsp->pid_ns);
>> goto out_pid;
>> + }
>>
>> new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
>> - if (IS_ERR(new_nsp->user_ns))
>> + if (IS_ERR(new_nsp->user_ns)) {
>> + err = PTR_ERR(new_nsp->user_ns);
>>
> Hmm.. copy_user_ns() ? I don't see this in rc4-mm2.
it's in the -mm stack.
C.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: PATCH -mm] fix create_new_namespaces() return value
2007-06-11 16:22 ` Badari Pulavarty
2007-06-12 7:49 ` Cedric Le Goater
@ 2007-06-12 12:19 ` Cedric Le Goater
1 sibling, 0 replies; 4+ messages in thread
From: Cedric Le Goater @ 2007-06-12 12:19 UTC (permalink / raw)
To: Badari Pulavarty
Cc: Linux Kernel Mailing List, Andrew Morton, Pavel Emelianov,
Herbert Poetzl, Eric W. Biederman, Serge E. Hallyn,
Linux Containers
Badari Pulavarty wrote:
>
>
> Cedric Le Goater wrote:
>
>> The following patch modifies create_new_namespaces() to also use the
>> errors returned by the copy_*_ns routines and not to systematically
>> return ENOMEM.
>>
>
> In my initial version, I did same. It doesn't work :(
>
> copy_*_ns() routines doesn't return any errors. All they return is NULL
> in case of a
> failure + with the exception of copy_mnt_ns, there are no other failure
> cases.
> So, there is no way to find out why the copy_*_ns() routines failed from
> create_new_namespaces().
> If you really really want to do this, change all copy_*_ns() routines to
> returns meaningful
> errors instead of NULL.
Here's a second try to apply on top of -mm branch,
Thanks for the review Badari.
C.
The following patch modifies create_new_namespaces() to also use the
errors returned by the copy_*_ns routines and not to systematically
return ENOMEM.
Changes since [try #1]:
- fixed return values of clone_*_ns() routines
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Eric W. Biederman <ebiederm@xmission.com>
---
fs/namespace.c | 4 ++--
kernel/nsproxy.c | 23 +++++++++++++++++------
kernel/user_namespace.c | 6 +++---
kernel/utsname.c | 10 ++++++----
4 files changed, 28 insertions(+), 15 deletions(-)
Index: 2.6.22-rc4-mm2/kernel/nsproxy.c
===================================================================
--- 2.6.22-rc4-mm2.orig/kernel/nsproxy.c
+++ 2.6.22-rc4-mm2/kernel/nsproxy.c
@@ -58,30 +58,41 @@ static struct nsproxy *create_new_namesp
struct fs_struct *new_fs)
{
struct nsproxy *new_nsp;
+ int err;
new_nsp = clone_nsproxy(tsk->nsproxy);
if (!new_nsp)
return ERR_PTR(-ENOMEM);
new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
- if (IS_ERR(new_nsp->mnt_ns))
+ if (IS_ERR(new_nsp->mnt_ns)) {
+ err = PTR_ERR(new_nsp->mnt_ns);
goto out_ns;
+ }
new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
- if (IS_ERR(new_nsp->uts_ns))
+ if (IS_ERR(new_nsp->uts_ns)) {
+ err = PTR_ERR(new_nsp->uts_ns);
goto out_uts;
+ }
new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
- if (IS_ERR(new_nsp->ipc_ns))
+ if (IS_ERR(new_nsp->ipc_ns)) {
+ err = PTR_ERR(new_nsp->ipc_ns);
goto out_ipc;
+ }
new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
- if (IS_ERR(new_nsp->pid_ns))
+ if (IS_ERR(new_nsp->pid_ns)) {
+ err = PTR_ERR(new_nsp->pid_ns);
goto out_pid;
+ }
new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
- if (IS_ERR(new_nsp->user_ns))
+ if (IS_ERR(new_nsp->user_ns)) {
+ err = PTR_ERR(new_nsp->user_ns);
goto out_user;
+ }
return new_nsp;
@@ -99,7 +110,7 @@ out_uts:
put_mnt_ns(new_nsp->mnt_ns);
out_ns:
kfree(new_nsp);
- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(err);
}
/*
Index: 2.6.22-rc4-mm2/fs/namespace.c
===================================================================
--- 2.6.22-rc4-mm2.orig/fs/namespace.c
+++ 2.6.22-rc4-mm2/fs/namespace.c
@@ -1599,7 +1599,7 @@ static struct mnt_namespace *dup_mnt_ns(
new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
if (!new_ns)
- return NULL;
+ return ERR_PTR(-ENOMEM);
atomic_set(&new_ns->count, 1);
INIT_LIST_HEAD(&new_ns->list);
@@ -1613,7 +1613,7 @@ static struct mnt_namespace *dup_mnt_ns(
if (IS_ERR(new_ns->root)) {
up_write(&namespace_sem);
kfree(new_ns);
- return NULL;
+ return ERR_PTR(-ENOMEM);;
}
spin_lock(&vfsmount_lock);
list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
Index: 2.6.22-rc4-mm2/kernel/user_namespace.c
===================================================================
--- 2.6.22-rc4-mm2.orig/kernel/user_namespace.c
+++ 2.6.22-rc4-mm2/kernel/user_namespace.c
@@ -34,7 +34,7 @@ static struct user_namespace *clone_user
ns = kmalloc(sizeof(struct user_namespace), GFP_KERNEL);
if (!ns)
- return NULL;
+ return ERR_PTR(-ENOMEM);
kref_init(&ns->kref);
@@ -45,7 +45,7 @@ static struct user_namespace *clone_user
ns->root_user = alloc_uid(ns, 0);
if (!ns->root_user) {
kfree(ns);
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
/* Reset current->user with a new one */
@@ -53,7 +53,7 @@ static struct user_namespace *clone_user
if (!new_user) {
free_uid(ns->root_user);
kfree(ns);
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
switch_uid(new_user);
Index: 2.6.22-rc4-mm2/kernel/utsname.c
===================================================================
--- 2.6.22-rc4-mm2.orig/kernel/utsname.c
+++ 2.6.22-rc4-mm2/kernel/utsname.c
@@ -13,6 +13,7 @@
#include <linux/uts.h>
#include <linux/utsname.h>
#include <linux/version.h>
+#include <linux/err.h>
/*
* Clone a new ns copying an original utsname, setting refcount to 1
@@ -24,10 +25,11 @@ static struct uts_namespace *clone_uts_n
struct uts_namespace *ns;
ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
- if (ns) {
- memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
- kref_init(&ns->kref);
- }
+ if (!ns)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
+ kref_init(&ns->kref);
return ns;
}
^ permalink raw reply [flat|nested] 4+ messages in thread