The patch titled
Subject: mempolicy: sanitize the usage of get_task_policy()
has been added to the -mm tree. Its filename is
mempolicy-sanitize-the-usage-of-get_task_policy.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mempolicy-sanitize-the-usage-of-get_task_policy.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mempolicy-sanitize-the-usage-of-get_task_policy.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: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: mempolicy: sanitize the usage of get_task_policy()
Cleanup + preparation. Every user of get_task_policy() calls it
unconditionally, even if it is not going to use the result.
get_task_policy() is cheap but still this does not look clean, plus
the code looks simpler if get_task_policy() is called only when this
is really needed.
Note: I hope this is correct, but it is not clear why vma_policy_mof()
doesn't fall back to get_task_policy() if ->get_policy() returns NULL.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff -puN mm/mempolicy.c~mempolicy-sanitize-the-usage-of-get_task_policy mm/mempolicy.c
--- a/mm/mempolicy.c~mempolicy-sanitize-the-usage-of-get_task_policy
+++ a/mm/mempolicy.c
@@ -1621,14 +1621,11 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulo
struct mempolicy *get_vma_policy(struct task_struct *task,
struct vm_area_struct *vma, unsigned long addr)
{
- struct mempolicy *pol = get_task_policy(task);
+ struct mempolicy *pol = NULL;
if (vma) {
if (vma->vm_ops && vma->vm_ops->get_policy) {
- struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
- addr);
- if (vpol)
- pol = vpol;
+ pol = vma->vm_ops->get_policy(vma, addr);
} else if (vma->vm_policy) {
pol = vma->vm_policy;
@@ -1643,12 +1640,15 @@ struct mempolicy *get_vma_policy(struct
}
}
+ if (!pol)
+ pol = get_task_policy(task);
+
return pol;
}
bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma)
{
- struct mempolicy *pol = get_task_policy(task);
+ struct mempolicy *pol = NULL;
if (vma) {
if (vma->vm_ops && vma->vm_ops->get_policy) {
@@ -1660,11 +1660,14 @@ bool vma_policy_mof(struct task_struct *
mpol_cond_put(pol);
return ret;
- } else if (vma->vm_policy) {
- pol = vma->vm_policy;
}
+
+ pol = vma->vm_policy;
}
+ if (!pol)
+ pol = get_task_policy(task);
+
return pol->flags & MPOL_F_MOF;
}
@@ -2068,12 +2071,12 @@ retry_cpuset:
*/
struct page *alloc_pages_current(gfp_t gfp, unsigned order)
{
- struct mempolicy *pol = get_task_policy(current);
+ struct mempolicy *pol = &default_policy;
struct page *page;
unsigned int cpuset_mems_cookie;
- if (in_interrupt() || (gfp & __GFP_THISNODE))
- pol = &default_policy;
+ if (!in_interrupt() && !(gfp & __GFP_THISNODE))
+ pol = get_task_policy(current);
retry_cpuset:
cpuset_mems_cookie = read_mems_allowed_begin();
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
prctl-pr_set_mm-introduce-pr_set_mm_map-operation-v4.patch
mempolicy-change-alloc_pages_vma-to-use-mpol_cond_put.patch
mempolicy-change-get_task_policy-to-return-default_policy-rather-than-null.patch
mempolicy-sanitize-the-usage-of-get_task_policy.patch
mempolicy-remove-the-task-arg-of-vma_policy_mof-and-simplify-it.patch
mempolicy-introduce-__get_vma_policy-export-get_task_policy.patch
mempolicy-fix-show_numa_map-vs-exec-do_set_mempolicy-race.patch
mempolicy-kill-do_set_mempolicy-down_writemm-mmap_sem.patch
mempolicy-unexport-get_vma_policy-and-remove-its-task-arg.patch
earlyprintk-re-enable-earlyprintk-calling-early_param.patch
fs-proc-task_mmuc-dont-use-task-mm-in-m_start-and-show_map.patch
fs-proc-task_mmuc-unify-simplify-do_maps_open-and-numa_maps_open.patch
proc-introduce-proc_mem_open.patch
fs-proc-task_mmuc-shift-mm_access-from-m_start-to-proc_maps_open.patch
fs-proc-task_mmuc-shift-mm_access-from-m_start-to-proc_maps_open-checkpatch-fixes.patch
fs-proc-task_mmuc-simplify-the-vma_stop-logic.patch
fs-proc-task_mmuc-simplify-the-vma_stop-logic-checkpatch-fixes.patch
fs-proc-task_mmuc-cleanup-the-tail_vma-horror-in-m_next.patch
fs-proc-task_mmuc-shift-priv-task-=-null-from-m_start-to-m_stop.patch
fs-proc-task_mmuc-kill-the-suboptimal-and-confusing-m-version-logic.patch
fs-proc-task_mmuc-simplify-m_start-to-make-it-readable.patch
fs-proc-task_mmuc-introduce-m_next_vma-helper.patch
fs-proc-task_mmuc-reintroduce-m-version-logic.patch
fs-proc-task_mmuc-update-m-version-in-the-main-loop-in-m_start.patch
fs-proc-task_nommuc-change-maps_open-to-use-__seq_open_private.patch
fs-proc-task_nommuc-shift-mm_access-from-m_start-to-proc_maps_open.patch
fs-proc-task_nommuc-shift-mm_access-from-m_start-to-proc_maps_open-checkpatch-fixes.patch
fs-proc-task_nommuc-dont-use-priv-task-mm.patch
proc-maps-replace-proc_maps_private-pid-with-struct-inode-inode.patch
proc-maps-make-vm_is_stack-logic-namespace-friendly.patch
ipc-shm-kill-the-historical-wrong-mm-start_stack-check.patch
linux-next.patch
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