mm: merge parameters for change_protection()

change_protection() was used by either the NUMA or mprotect() code, there's one parameter for each of the callers (dirty_accountable and prot_numa). Further, these parameters are passed along the calls: - change_protection_range() - change_p4d_range() - change_pud_range() - change_pmd_range() - ... Now we introduce a flag for change_protect() and all these helpers to replace these parameters. Then we can avoid passing multiple parameters multiple times along the way. More importantly, it'll greatly simplify the work if we want to introduce any new parameters to change_protection(). In the follow up patches, a new parameter for userfaultfd write protection will be introduced. No functional change at all.

Peter Xu committed 6 years ago

Commit 58705441 parent 72981e05 files · +33 −17Browse files

Unified · Split

5 files

include/linux/huge_mm.h +1 −1
include/linux/mm.h +13 −1
mm/huge_memory.c +2 −1
mm/mempolicy.c +1 −1
mm/mprotect.c +16 −13

include/linux/huge_mm.h+1−1

@@ -46,7 +46,7 @@ extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, · 45 unmodified lines
46	pmd_t old_pmd, pmd_t new_pmd);	46	pmd_t old_pmd, pmd_t new_pmd);
47	extern int change_huge_pmd(struct vm_area_struct vma, pmd_t pmd,	47	extern int change_huge_pmd(struct vm_area_struct vma, pmd_t pmd,
48	unsigned long addr, pgprot_t newprot,	48	unsigned long addr, pgprot_t newprot,
49	int prot_numa);	49	unsigned long cp_flags);
50	vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,	50	vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,
51	pgprot_t pgprot, bool write);	51	pgprot_t pgprot, bool write);
52		52

include/linux/mm.h+13−1

@@ -1771,9 +1771,21 @@ extern unsigned long move_page_tables(struct vm_area_struct *vma, · 1770 unmodified lines
1771	unsigned long old_addr, struct vm_area_struct *new_vma,	1771	unsigned long old_addr, struct vm_area_struct *new_vma,
1772	unsigned long new_addr, unsigned long len,	1772	unsigned long new_addr, unsigned long len,
1773	bool need_rmap_locks);	1773	bool need_rmap_locks);
		1774
		1775	/*
		1776	* Flags used by change_protection(). For now we make it a bitmap so
		1777	* that we can pass in multiple flags just like parameters. However
		1778	* for now all the callers are only use one of the flags at the same
		1779	* time.
		1780	*/
		1781	/* Whether we should allow dirty bit accounting */
		1782	#define MM_CP_DIRTY_ACCT (1UL << 0)
		1783	/* Whether this protection change is for NUMA hints */
		1784	#define MM_CP_PROT_NUMA (1UL << 1)
		1785
1774	extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,	1786	extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
1775	unsigned long end, pgprot_t newprot,	1787	unsigned long end, pgprot_t newprot,
1776	int dirty_accountable, int prot_numa);	1788	unsigned long cp_flags);
1777	extern int mprotect_fixup(struct vm_area_struct *vma,	1789	extern int mprotect_fixup(struct vm_area_struct *vma,
1778	struct vm_area_struct **pprev, unsigned long start,	1790	struct vm_area_struct **pprev, unsigned long start,
1779	unsigned long end, unsigned long newflags);	1791	unsigned long end, unsigned long newflags);

mm/huge_memory.c+2−1

  *  - HPAGE_PMD_NR is protections changed and TLB flush necessary
  */
 int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
-		unsigned long addr, pgprot_t newprot, int prot_numa)
+		unsigned long addr, pgprot_t newprot, unsigned long cp_flags)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	spinlock_t *ptl;
 	pmd_t entry;
 	bool preserve_write;
 	int ret;
+	bool prot_numa = cp_flags & MM_CP_PROT_NUMA;
 	ptl = __pmd_trans_huge_lock(pmd, vma);
 	if (!ptl)

mm/mempolicy.c+1−1

@@ -627,7 +627,7 @@ unsigned long change_prot_numa(struct vm_area_struct *vma, · 626 unmodified lines
627	{	627	{
628	int nr_updated;	628	int nr_updated;
629		629
630	nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1);	630	nr_updated = change_protection(vma, addr, end, PAGE_NONE, MM_CP_PROT_NUMA);
631	if (nr_updated)	631	if (nr_updated)
632	count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);	632	count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
633		633

mm/mprotect.c+16−13

 static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 		unsigned long addr, unsigned long end, pgprot_t newprot,
-		int dirty_accountable, int prot_numa)
+		unsigned long cp_flags)
 {
 	pte_t *pte, oldpte;
 	spinlock_t *ptl;
 	unsigned long pages = 0;
 	int target_node = NUMA_NO_NODE;
+	bool dirty_accountable = cp_flags & MM_CP_DIRTY_ACCT;
+	bool prot_numa = cp_flags & MM_CP_PROT_NUMA;
 	/*
 	 * Can be called with only the mmap_sem for reading by
 static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		pud_t *pud, unsigned long addr, unsigned long end,
-		pgprot_t newprot, int dirty_accountable, int prot_numa)
+		pgprot_t newprot, unsigned long cp_flags)
 {
 	pmd_t *pmd;
 	unsigned long next;
 				__split_huge_pmd(vma, pmd, addr, false, NULL);
 			} else {
 				int nr_ptes = change_huge_pmd(vma, pmd, addr,
-						newprot, prot_numa);
+							      newprot, cp_flags);
 				if (nr_ptes) {
 					if (nr_ptes == HPAGE_PMD_NR) {
 			/* fall through, the trans huge pmd just split */
 		}
 		this_pages = change_pte_range(vma, pmd, addr, next, newprot,
-				 dirty_accountable, prot_numa);
+					      cp_flags);
 		pages += this_pages;
 next:
 		cond_resched();
 static inline unsigned long change_pud_range(struct vm_area_struct *vma,
 		p4d_t *p4d, unsigned long addr, unsigned long end,
-		pgprot_t newprot, int dirty_accountable, int prot_numa)
+		pgprot_t newprot, unsigned long cp_flags)
 {
 	pud_t *pud;
 	unsigned long next;
 		if (pud_none_or_clear_bad(pud))
 			continue;
 		pages += change_pmd_range(vma, pud, addr, next, newprot,
-				 dirty_accountable, prot_numa);
+					  cp_flags);
 	} while (pud++, addr = next, addr != end);
 	return pages;
 static inline unsigned long change_p4d_range(struct vm_area_struct *vma,
 		pgd_t *pgd, unsigned long addr, unsigned long end,
-		pgprot_t newprot, int dirty_accountable, int prot_numa)
+		pgprot_t newprot, unsigned long cp_flags)
 {
 	p4d_t *p4d;
 	unsigned long next;
 		if (p4d_none_or_clear_bad(p4d))
 			continue;
 		pages += change_pud_range(vma, p4d, addr, next, newprot,
-				 dirty_accountable, prot_numa);
+					  cp_flags);
 	} while (p4d++, addr = next, addr != end);
 	return pages;
 static unsigned long change_protection_range(struct vm_area_struct *vma,
 		unsigned long addr, unsigned long end, pgprot_t newprot,
-		int dirty_accountable, int prot_numa)
+		unsigned long cp_flags)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	pgd_t *pgd;
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
 		pages += change_p4d_range(vma, pgd, addr, next, newprot,
-				 dirty_accountable, prot_numa);
+					  cp_flags);
 	} while (pgd++, addr = next, addr != end);
 	/* Only flush the TLB if we actually modified any entries: */
 unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
 		       unsigned long end, pgprot_t newprot,
-		       int dirty_accountable, int prot_numa)
+		       unsigned long cp_flags)
 {
 	unsigned long pages;
 	if (is_vm_hugetlb_page(vma))
 		pages = hugetlb_change_protection(vma, start, end, newprot);
 	else
-		pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa);
+		pages = change_protection_range(vma, start, end, newprot,
+						cp_flags);
 	return pages;
 }
 	vma_set_page_prot(vma);
 	change_protection(vma, start, end, vma->vm_page_prot,
-			  dirty_accountable, 0);
+			  dirty_accountable ? MM_CP_DIRTY_ACCT : 0);
 	/*
 	 * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major