Commit 225dda6b authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Zheng Zengkai
Browse files

mm: Tag VMA with VM_CDM flag explicitly during mbind(MPOL_BIND) and page fault 

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4JMLR


CVE: NA
-------------------

Mark all the applicable VMAs with VM_CDM explicitly during mbind(MPOL_BIND)
call if the user provided nodemask has a CDM node.

Mark the corresponding VMA with VM_CDM flag if the allocated page happens
to be from a CDM node. This can be expensive from performance stand point.
There are multiple checks to avoid an expensive page_to_nid lookup but it
can be optimized further.

Signed-off-by: default avatarAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: default avatarLijun Fang <fanglijun3@huawei.com>
Reviewed-by: default avatarWeilong Chen <chenweilong@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent a8cc75dd

include/linux/mm.h

+5 −0
Original line number Diff line number Diff line
@@ -282,6 +282,11 @@ extern unsigned int kobjsize(const void *objp); 
#define VM_ACCOUNT	0x00100000	/* Is a VM accounted object */

#define VM_NORESERVE	0x00200000	/* should the VM suppress accounting */

#define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */



#ifdef CONFIG_COHERENT_DEVICE

#define VM_CDM		0x00800000	/* Contains coherent device memory */

#endif



#define VM_SYNC		0x00800000	/* Synchronous page faults */

#define VM_ARCH_1	0x01000000	/* Architecture-specific flag */

#define VM_WIPEONFORK	0x02000000	/* Wipe VMA contents in child. */

mm/mempolicy.c

+41 −0
Original line number Diff line number Diff line
@@ -190,6 +190,42 @@ static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, 
	nodes_onto(*ret, tmp, *rel);

}



#ifdef CONFIG_COHERENT_DEVICE

static inline void set_vm_cdm(struct vm_area_struct *vma)

{

	vma->vm_flags |= VM_CDM;

}



static inline void clr_vm_cdm(struct vm_area_struct *vma)

{

	vma->vm_flags &= ~VM_CDM;

}



static void mark_vma_cdm(nodemask_t *nmask,

		struct page *page, struct vm_area_struct *vma)

{

	if (!page || !vma)

		return;



	if (vma->vm_flags & VM_CDM)

		return;



	if (nmask && !nodemask_has_cdm(*nmask))

		return;



	if (is_cdm_node(page_to_nid(page)))

		vma->vm_flags |= VM_CDM;

}

#else

static inline void set_vm_cdm(struct vm_area_struct *vma) { }

static inline void clr_vm_cdm(struct vm_area_struct *vma) { }



static void mark_vma_cdm(nodemask_t *nmask,

		struct page *page, struct vm_area_struct *vma)

{

}

#endif



static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)

{

	if (nodes_empty(*nodes))
@@ -822,6 +858,10 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, 
		vmstart = max(start, vma->vm_start);

		vmend   = min(end, vma->vm_end);



		if (new_pol && (new_pol->mode == MPOL_BIND) &&

				nodemask_has_cdm(new_pol->v.nodes))

			set_vm_cdm(vma);



		if (mpol_equal(vma_policy(vma), new_pol))

			continue;
@@ -2224,6 +2264,7 @@ struct page *alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, 
	nmask = policy_nodemask(gfp, pol);

	preferred_nid = policy_node(gfp, pol, node);

	page = __alloc_pages(gfp, order, preferred_nid, nmask);

	mark_vma_cdm(nmask, page, vma);

	mpol_cond_put(pol);

out:

	return page;