* [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
@ 2017-12-01 9:55 ` Yisheng Xie
0 siblings, 0 replies; 6+ messages in thread
From: Yisheng Xie @ 2017-12-01 9:55 UTC (permalink / raw)
To: akpm
Cc: linux-mm, linux-kernel, linux-api, Yisheng Xie, Andi Kleen,
Chris Salls, Christopher Lameter, David Rientjes, Ingo Molnar,
Naoya Horiguchi, Tan Xiaojun, Vlastimil Babka
As in manpage of migrate_pages, the errno should be set to EINVAL when
none of the node IDs specified by new_nodes are on-line and allowed by the
process's current cpuset context, or none of the specified nodes contain
memory. However, when test by following case:
new_nodes = 0;
old_nodes = 0xf;
ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
The ret will be 0 and no errno is set. As the new_nodes is empty, we
should expect EINVAL as documented.
To fix the case like above, this patch check whether target nodes AND
current task_nodes is empty, and then check whether AND
node_states[N_MEMORY] is empty.
Meanwhile,this patch also remove the check of EPERM on CAP_SYS_NICE.
The caller of migrate_pages should be able to migrate the target process
pages anywhere the caller can allocate memory, if the caller can access
the mm_struct.
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Chris Salls <salls@cs.ucsb.edu>
Cc: Christopher Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Tan Xiaojun <tanxiaojun@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
---
v3:
* check whether node is empty after AND current task node, and then nodes
which have memory
v4:
* remove the check of EPERM on CAP_SYS_NICE.
Hi Vlastimil and Christopher,
Could you please help to review this version?
Thanks
Yisheng Xie
mm/mempolicy.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 65df28d..4da74b6 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1426,17 +1426,14 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
}
rcu_read_unlock();
- task_nodes = cpuset_mems_allowed(task);
- /* Is the user allowed to access the target nodes? */
- if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
- err = -EPERM;
+ task_nodes = cpuset_mems_allowed(current);
+ nodes_and(*new, *new, task_nodes);
+ if (nodes_empty(*new))
goto out_put;
- }
- if (!nodes_subset(*new, node_states[N_MEMORY])) {
- err = -EINVAL;
+ nodes_and(*new, *new, node_states[N_MEMORY]);
+ if (nodes_empty(*new))
goto out_put;
- }
err = security_task_movememory(task);
if (err)
--
1.7.12.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
@ 2017-12-01 9:55 ` Yisheng Xie
0 siblings, 0 replies; 6+ messages in thread
From: Yisheng Xie @ 2017-12-01 9:55 UTC (permalink / raw)
To: akpm
Cc: linux-mm, linux-kernel, linux-api, Yisheng Xie, Andi Kleen,
Chris Salls, Christopher Lameter, David Rientjes, Ingo Molnar,
Naoya Horiguchi, Tan Xiaojun, Vlastimil Babka
As in manpage of migrate_pages, the errno should be set to EINVAL when
none of the node IDs specified by new_nodes are on-line and allowed by the
process's current cpuset context, or none of the specified nodes contain
memory. However, when test by following case:
new_nodes = 0;
old_nodes = 0xf;
ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
The ret will be 0 and no errno is set. As the new_nodes is empty, we
should expect EINVAL as documented.
To fix the case like above, this patch check whether target nodes AND
current task_nodes is empty, and then check whether AND
node_states[N_MEMORY] is empty.
Meanwhile,this patch also remove the check of EPERM on CAP_SYS_NICE.
The caller of migrate_pages should be able to migrate the target process
pages anywhere the caller can allocate memory, if the caller can access
the mm_struct.
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Chris Salls <salls@cs.ucsb.edu>
Cc: Christopher Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Tan Xiaojun <tanxiaojun@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
---
v3:
* check whether node is empty after AND current task node, and then nodes
which have memory
v4:
* remove the check of EPERM on CAP_SYS_NICE.
Hi Vlastimil and Christopher,
Could you please help to review this version?
Thanks
Yisheng Xie
mm/mempolicy.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 65df28d..4da74b6 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1426,17 +1426,14 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
}
rcu_read_unlock();
- task_nodes = cpuset_mems_allowed(task);
- /* Is the user allowed to access the target nodes? */
- if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
- err = -EPERM;
+ task_nodes = cpuset_mems_allowed(current);
+ nodes_and(*new, *new, task_nodes);
+ if (nodes_empty(*new))
goto out_put;
- }
- if (!nodes_subset(*new, node_states[N_MEMORY])) {
- err = -EINVAL;
+ nodes_and(*new, *new, node_states[N_MEMORY]);
+ if (nodes_empty(*new))
goto out_put;
- }
err = security_task_movememory(task);
if (err)
--
1.7.12.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
2017-12-01 9:55 ` Yisheng Xie
@ 2017-12-01 15:18 ` Vlastimil Babka
-1 siblings, 0 replies; 6+ messages in thread
From: Vlastimil Babka @ 2017-12-01 15:18 UTC (permalink / raw)
To: Yisheng Xie, akpm
Cc: linux-mm, linux-kernel, linux-api, Andi Kleen, Chris Salls,
Christopher Lameter, David Rientjes, Ingo Molnar,
Naoya Horiguchi, Tan Xiaojun
On 12/01/2017 10:55 AM, Yisheng Xie wrote:
> As in manpage of migrate_pages, the errno should be set to EINVAL when
> none of the node IDs specified by new_nodes are on-line and allowed by the
> process's current cpuset context, or none of the specified nodes contain
> memory. However, when test by following case:
>
> new_nodes = 0;
> old_nodes = 0xf;
> ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
>
> The ret will be 0 and no errno is set. As the new_nodes is empty, we
> should expect EINVAL as documented.
>
> To fix the case like above, this patch check whether target nodes AND
> current task_nodes is empty, and then check whether AND
> node_states[N_MEMORY] is empty.
>
> Meanwhile,this patch also remove the check of EPERM on CAP_SYS_NICE.
> The caller of migrate_pages should be able to migrate the target process
> pages anywhere the caller can allocate memory, if the caller can access
> the mm_struct.
>
> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
> Cc: Andi Kleen <ak@linux.intel.com>
> Cc: Chris Salls <salls@cs.ucsb.edu>
> Cc: Christopher Lameter <cl@linux.com>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Cc: Tan Xiaojun <tanxiaojun@huawei.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> ---
> v3:
> * check whether node is empty after AND current task node, and then nodes
> which have memory
> v4:
> * remove the check of EPERM on CAP_SYS_NICE.
>
> Hi Vlastimil and Christopher,
>
> Could you please help to review this version?
Hi, I think we should stay with v3 after all. What I missed when
reviewing it, is that the EPERM check is for cpuset_mems_allowed(task)
and in v3 you add EINVAL check for cpuset_mems_allowed(current), which
may not be the same, and the intention of CAP_SYS_NICE is not whether we
can bypass our own cpuset, but whether we can bypass the target task's
cpuset. Sorry for the confusion.
> Thanks
> Yisheng Xie
>
> mm/mempolicy.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 65df28d..4da74b6 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1426,17 +1426,14 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
> }
> rcu_read_unlock();
>
> - task_nodes = cpuset_mems_allowed(task);
> - /* Is the user allowed to access the target nodes? */
> - if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
> - err = -EPERM;
> + task_nodes = cpuset_mems_allowed(current);
> + nodes_and(*new, *new, task_nodes);
> + if (nodes_empty(*new))
> goto out_put;
> - }
>
> - if (!nodes_subset(*new, node_states[N_MEMORY])) {
> - err = -EINVAL;
> + nodes_and(*new, *new, node_states[N_MEMORY]);
> + if (nodes_empty(*new))
> goto out_put;
> - }
>
> err = security_task_movememory(task);
> if (err)
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
@ 2017-12-01 15:18 ` Vlastimil Babka
0 siblings, 0 replies; 6+ messages in thread
From: Vlastimil Babka @ 2017-12-01 15:18 UTC (permalink / raw)
To: Yisheng Xie, akpm
Cc: linux-mm, linux-kernel, linux-api, Andi Kleen, Chris Salls,
Christopher Lameter, David Rientjes, Ingo Molnar,
Naoya Horiguchi, Tan Xiaojun
On 12/01/2017 10:55 AM, Yisheng Xie wrote:
> As in manpage of migrate_pages, the errno should be set to EINVAL when
> none of the node IDs specified by new_nodes are on-line and allowed by the
> process's current cpuset context, or none of the specified nodes contain
> memory. However, when test by following case:
>
> new_nodes = 0;
> old_nodes = 0xf;
> ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
>
> The ret will be 0 and no errno is set. As the new_nodes is empty, we
> should expect EINVAL as documented.
>
> To fix the case like above, this patch check whether target nodes AND
> current task_nodes is empty, and then check whether AND
> node_states[N_MEMORY] is empty.
>
> Meanwhile,this patch also remove the check of EPERM on CAP_SYS_NICE.
> The caller of migrate_pages should be able to migrate the target process
> pages anywhere the caller can allocate memory, if the caller can access
> the mm_struct.
>
> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
> Cc: Andi Kleen <ak@linux.intel.com>
> Cc: Chris Salls <salls@cs.ucsb.edu>
> Cc: Christopher Lameter <cl@linux.com>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Cc: Tan Xiaojun <tanxiaojun@huawei.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> ---
> v3:
> * check whether node is empty after AND current task node, and then nodes
> which have memory
> v4:
> * remove the check of EPERM on CAP_SYS_NICE.
>
> Hi Vlastimil and Christopher,
>
> Could you please help to review this version?
Hi, I think we should stay with v3 after all. What I missed when
reviewing it, is that the EPERM check is for cpuset_mems_allowed(task)
and in v3 you add EINVAL check for cpuset_mems_allowed(current), which
may not be the same, and the intention of CAP_SYS_NICE is not whether we
can bypass our own cpuset, but whether we can bypass the target task's
cpuset. Sorry for the confusion.
> Thanks
> Yisheng Xie
>
> mm/mempolicy.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 65df28d..4da74b6 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1426,17 +1426,14 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
> }
> rcu_read_unlock();
>
> - task_nodes = cpuset_mems_allowed(task);
> - /* Is the user allowed to access the target nodes? */
> - if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
> - err = -EPERM;
> + task_nodes = cpuset_mems_allowed(current);
> + nodes_and(*new, *new, task_nodes);
> + if (nodes_empty(*new))
> goto out_put;
> - }
>
> - if (!nodes_subset(*new, node_states[N_MEMORY])) {
> - err = -EINVAL;
> + nodes_and(*new, *new, node_states[N_MEMORY]);
> + if (nodes_empty(*new))
> goto out_put;
> - }
>
> err = security_task_movememory(task);
> if (err)
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
2017-12-01 15:18 ` Vlastimil Babka
@ 2017-12-04 0:49 ` Yisheng Xie
-1 siblings, 0 replies; 6+ messages in thread
From: Yisheng Xie @ 2017-12-04 0:49 UTC (permalink / raw)
To: Vlastimil Babka, akpm
Cc: linux-mm, linux-kernel, linux-api, Andi Kleen, Chris Salls,
Christopher Lameter, David Rientjes, Ingo Molnar,
Naoya Horiguchi, Tan Xiaojun
Hi Vlastimil,
On 2017/12/1 23:18, Vlastimil Babka wrote:
> On 12/01/2017 10:55 AM, Yisheng Xie wrote:
>> As in manpage of migrate_pages, the errno should be set to EINVAL when
>> none of the node IDs specified by new_nodes are on-line and allowed by the
>> process's current cpuset context, or none of the specified nodes contain
>> memory. However, when test by following case:
>>
>> new_nodes = 0;
>> old_nodes = 0xf;
>> ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
>>
>> The ret will be 0 and no errno is set. As the new_nodes is empty, we
>> should expect EINVAL as documented.
>>
>> To fix the case like above, this patch check whether target nodes AND
>> current task_nodes is empty, and then check whether AND
>> node_states[N_MEMORY] is empty.
>>
>> Meanwhile,this patch also remove the check of EPERM on CAP_SYS_NICE.
>> The caller of migrate_pages should be able to migrate the target process
>> pages anywhere the caller can allocate memory, if the caller can access
>> the mm_struct.
>>
>> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
>> Cc: Andi Kleen <ak@linux.intel.com>
>> Cc: Chris Salls <salls@cs.ucsb.edu>
>> Cc: Christopher Lameter <cl@linux.com>
>> Cc: David Rientjes <rientjes@google.com>
>> Cc: Ingo Molnar <mingo@kernel.org>
>> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
>> Cc: Tan Xiaojun <tanxiaojun@huawei.com>
>> Cc: Vlastimil Babka <vbabka@suse.cz>
>> ---
>> v3:
>> * check whether node is empty after AND current task node, and then nodes
>> which have memory
>> v4:
>> * remove the check of EPERM on CAP_SYS_NICE.
>>
>> Hi Vlastimil and Christopher,
>>
>> Could you please help to review this version?
>
> Hi, I think we should stay with v3 after all. What I missed when
> reviewing it, is that the EPERM check is for cpuset_mems_allowed(task)
> and in v3 you add EINVAL check for cpuset_mems_allowed(current), which
> may not be the same, and the intention of CAP_SYS_NICE is not whether we
> can bypass our own cpuset, but whether we can bypass the target task's
> cpuset. Sorry for the confusion.
Ok, so please ignore this version.
Thanks
Yisheng Xie
>
>
> .
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
@ 2017-12-04 0:49 ` Yisheng Xie
0 siblings, 0 replies; 6+ messages in thread
From: Yisheng Xie @ 2017-12-04 0:49 UTC (permalink / raw)
To: Vlastimil Babka, akpm
Cc: linux-mm, linux-kernel, linux-api, Andi Kleen, Chris Salls,
Christopher Lameter, David Rientjes, Ingo Molnar,
Naoya Horiguchi, Tan Xiaojun
Hi Vlastimil,
On 2017/12/1 23:18, Vlastimil Babka wrote:
> On 12/01/2017 10:55 AM, Yisheng Xie wrote:
>> As in manpage of migrate_pages, the errno should be set to EINVAL when
>> none of the node IDs specified by new_nodes are on-line and allowed by the
>> process's current cpuset context, or none of the specified nodes contain
>> memory. However, when test by following case:
>>
>> new_nodes = 0;
>> old_nodes = 0xf;
>> ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
>>
>> The ret will be 0 and no errno is set. As the new_nodes is empty, we
>> should expect EINVAL as documented.
>>
>> To fix the case like above, this patch check whether target nodes AND
>> current task_nodes is empty, and then check whether AND
>> node_states[N_MEMORY] is empty.
>>
>> Meanwhile,this patch also remove the check of EPERM on CAP_SYS_NICE.
>> The caller of migrate_pages should be able to migrate the target process
>> pages anywhere the caller can allocate memory, if the caller can access
>> the mm_struct.
>>
>> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
>> Cc: Andi Kleen <ak@linux.intel.com>
>> Cc: Chris Salls <salls@cs.ucsb.edu>
>> Cc: Christopher Lameter <cl@linux.com>
>> Cc: David Rientjes <rientjes@google.com>
>> Cc: Ingo Molnar <mingo@kernel.org>
>> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
>> Cc: Tan Xiaojun <tanxiaojun@huawei.com>
>> Cc: Vlastimil Babka <vbabka@suse.cz>
>> ---
>> v3:
>> * check whether node is empty after AND current task node, and then nodes
>> which have memory
>> v4:
>> * remove the check of EPERM on CAP_SYS_NICE.
>>
>> Hi Vlastimil and Christopher,
>>
>> Could you please help to review this version?
>
> Hi, I think we should stay with v3 after all. What I missed when
> reviewing it, is that the EPERM check is for cpuset_mems_allowed(task)
> and in v3 you add EINVAL check for cpuset_mems_allowed(current), which
> may not be the same, and the intention of CAP_SYS_NICE is not whether we
> can bypass our own cpuset, but whether we can bypass the target task's
> cpuset. Sorry for the confusion.
Ok, so please ignore this version.
Thanks
Yisheng Xie
>
>
> .
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-12-04 0:50 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-12-01 9:55 [PATCH v4 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages Yisheng Xie
2017-12-01 9:55 ` Yisheng Xie
2017-12-01 15:18 ` Vlastimil Babka
2017-12-01 15:18 ` Vlastimil Babka
2017-12-04 0:49 ` Yisheng Xie
2017-12-04 0:49 ` Yisheng Xie
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