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Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r--mm/huge_memory.c109
1 files changed, 91 insertions, 18 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 24ad53b4dfc0..6ecd1045113b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -326,7 +326,7 @@ static struct attribute *hugepage_attr[] = {
&defrag_attr.attr,
&use_zero_page_attr.attr,
&hpage_pmd_size_attr.attr,
-#if defined(CONFIG_SHMEM) && defined(CONFIG_TRANSPARENT_HUGE_PAGECACHE)
+#ifdef CONFIG_SHMEM
&shmem_enabled_attr.attr,
#endif
#ifdef CONFIG_DEBUG_VM
@@ -597,6 +597,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
if (mem_cgroup_try_charge_delay(page, vma->vm_mm, gfp, &memcg, true)) {
put_page(page);
count_vm_event(THP_FAULT_FALLBACK);
+ count_vm_event(THP_FAULT_FALLBACK_CHARGE);
return VM_FAULT_FALLBACK;
}
@@ -824,11 +825,24 @@ out_unlock:
pte_free(mm, pgtable);
}
-vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write)
+/**
+ * vmf_insert_pfn_pmd_prot - insert a pmd size pfn
+ * @vmf: Structure describing the fault
+ * @pfn: pfn to insert
+ * @pgprot: page protection to use
+ * @write: whether it's a write fault
+ *
+ * Insert a pmd size pfn. See vmf_insert_pfn() for additional info and
+ * also consult the vmf_insert_mixed_prot() documentation when
+ * @pgprot != @vmf->vma->vm_page_prot.
+ *
+ * Return: vm_fault_t value.
+ */
+vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,
+ pgprot_t pgprot, bool write)
{
unsigned long addr = vmf->address & PMD_MASK;
struct vm_area_struct *vma = vmf->vma;
- pgprot_t pgprot = vma->vm_page_prot;
pgtable_t pgtable = NULL;
/*
@@ -856,7 +870,7 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write)
insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable);
return VM_FAULT_NOPAGE;
}
-EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd);
+EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd_prot);
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma)
@@ -902,11 +916,24 @@ out_unlock:
spin_unlock(ptl);
}
-vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write)
+/**
+ * vmf_insert_pfn_pud_prot - insert a pud size pfn
+ * @vmf: Structure describing the fault
+ * @pfn: pfn to insert
+ * @pgprot: page protection to use
+ * @write: whether it's a write fault
+ *
+ * Insert a pud size pfn. See vmf_insert_pfn() for additional info and
+ * also consult the vmf_insert_mixed_prot() documentation when
+ * @pgprot != @vmf->vma->vm_page_prot.
+ *
+ * Return: vm_fault_t value.
+ */
+vm_fault_t vmf_insert_pfn_pud_prot(struct vm_fault *vmf, pfn_t pfn,
+ pgprot_t pgprot, bool write)
{
unsigned long addr = vmf->address & PUD_MASK;
struct vm_area_struct *vma = vmf->vma;
- pgprot_t pgprot = vma->vm_page_prot;
/*
* If we had pud_special, we could avoid all these restrictions,
@@ -927,7 +954,7 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write)
insert_pfn_pud(vma, addr, vmf->pud, pfn, pgprot, write);
return VM_FAULT_NOPAGE;
}
-EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud);
+EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud_prot);
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void touch_pmd(struct vm_area_struct *vma, unsigned long addr,
@@ -958,6 +985,11 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
*/
WARN_ONCE(flags & FOLL_COW, "mm: In follow_devmap_pmd with FOLL_COW set");
+ /* FOLL_GET and FOLL_PIN are mutually exclusive. */
+ if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
+ (FOLL_PIN | FOLL_GET)))
+ return NULL;
+
if (flags & FOLL_WRITE && !pmd_write(*pmd))
return NULL;
@@ -973,7 +1005,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
* device mapped pages can only be returned if the
* caller will manage the page reference count.
*/
- if (!(flags & FOLL_GET))
+ if (!(flags & (FOLL_GET | FOLL_PIN)))
return ERR_PTR(-EEXIST);
pfn += (addr & ~PMD_MASK) >> PAGE_SHIFT;
@@ -981,7 +1013,8 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
if (!*pgmap)
return ERR_PTR(-EFAULT);
page = pfn_to_page(pfn);
- get_page(page);
+ if (!try_grab_page(page, flags))
+ page = ERR_PTR(-ENOMEM);
return page;
}
@@ -1011,6 +1044,14 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
ret = -EAGAIN;
pmd = *src_pmd;
+ /*
+ * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA
+ * does not have the VM_UFFD_WP, which means that the uffd
+ * fork event is not enabled.
+ */
+ if (!(vma->vm_flags & VM_UFFD_WP))
+ pmd = pmd_clear_uffd_wp(pmd);
+
#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
if (unlikely(is_swap_pmd(pmd))) {
swp_entry_t entry = pmd_to_swp_entry(pmd);
@@ -1101,6 +1142,11 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
if (flags & FOLL_WRITE && !pud_write(*pud))
return NULL;
+ /* FOLL_GET and FOLL_PIN are mutually exclusive. */
+ if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
+ (FOLL_PIN | FOLL_GET)))
+ return NULL;
+
if (pud_present(*pud) && pud_devmap(*pud))
/* pass */;
else
@@ -1112,8 +1158,10 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
/*
* device mapped pages can only be returned if the
* caller will manage the page reference count.
+ *
+ * At least one of FOLL_GET | FOLL_PIN must be set, so assert that here:
*/
- if (!(flags & FOLL_GET))
+ if (!(flags & (FOLL_GET | FOLL_PIN)))
return ERR_PTR(-EEXIST);
pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT;
@@ -1121,7 +1169,8 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
if (!*pgmap)
return ERR_PTR(-EFAULT);
page = pfn_to_page(pfn);
- get_page(page);
+ if (!try_grab_page(page, flags))
+ page = ERR_PTR(-ENOMEM);
return page;
}
@@ -1406,6 +1455,7 @@ alloc:
put_page(page);
ret |= VM_FAULT_FALLBACK;
count_vm_event(THP_FAULT_FALLBACK);
+ count_vm_event(THP_FAULT_FALLBACK_CHARGE);
goto out;
}
@@ -1497,8 +1547,13 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
page = pmd_page(*pmd);
VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page);
+
+ if (!try_grab_page(page, flags))
+ return ERR_PTR(-ENOMEM);
+
if (flags & FOLL_TOUCH)
touch_pmd(vma, addr, pmd, flags);
+
if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
/*
* We don't mlock() pte-mapped THPs. This way we can avoid
@@ -1535,8 +1590,6 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
skip_mlock:
page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT;
VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page);
- if (flags & FOLL_GET)
- get_page(page);
out:
return page;
@@ -1802,7 +1855,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
tlb->fullmm);
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
- if (vma_is_dax(vma)) {
+ if (vma_is_special_huge(vma)) {
if (arch_needs_pgtable_deposit())
zap_deposited_table(tlb->mm, pmd);
spin_unlock(ptl);
@@ -1934,13 +1987,16 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
* - 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;
+ bool uffd_wp = cp_flags & MM_CP_UFFD_WP;
+ bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE;
ptl = __pmd_trans_huge_lock(pmd, vma);
if (!ptl)
@@ -2007,6 +2063,17 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
entry = pmd_modify(entry, newprot);
if (preserve_write)
entry = pmd_mk_savedwrite(entry);
+ if (uffd_wp) {
+ entry = pmd_wrprotect(entry);
+ entry = pmd_mkuffd_wp(entry);
+ } else if (uffd_wp_resolve) {
+ /*
+ * Leave the write bit to be handled by PF interrupt
+ * handler, then things like COW could be properly
+ * handled.
+ */
+ entry = pmd_clear_uffd_wp(entry);
+ }
ret = HPAGE_PMD_NR;
set_pmd_at(mm, addr, pmd, entry);
BUG_ON(vma_is_anonymous(vma) && !preserve_write && pmd_write(entry));
@@ -2066,7 +2133,7 @@ int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
*/
pudp_huge_get_and_clear_full(tlb->mm, addr, pud, tlb->fullmm);
tlb_remove_pud_tlb_entry(tlb, pud, addr);
- if (vma_is_dax(vma)) {
+ if (vma_is_special_huge(vma)) {
spin_unlock(ptl);
/* No zero page support yet */
} else {
@@ -2155,7 +2222,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
struct page *page;
pgtable_t pgtable;
pmd_t old_pmd, _pmd;
- bool young, write, soft_dirty, pmd_migration = false;
+ bool young, write, soft_dirty, pmd_migration = false, uffd_wp = false;
unsigned long addr;
int i;
@@ -2175,7 +2242,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
*/
if (arch_needs_pgtable_deposit())
zap_deposited_table(mm, pmd);
- if (vma_is_dax(vma))
+ if (vma_is_special_huge(vma))
return;
page = pmd_page(_pmd);
if (!PageDirty(page) && pmd_dirty(_pmd))
@@ -2230,6 +2297,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
write = is_write_migration_entry(entry);
young = false;
soft_dirty = pmd_swp_soft_dirty(old_pmd);
+ uffd_wp = pmd_swp_uffd_wp(old_pmd);
} else {
page = pmd_page(old_pmd);
if (pmd_dirty(old_pmd))
@@ -2237,6 +2305,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
write = pmd_write(old_pmd);
young = pmd_young(old_pmd);
soft_dirty = pmd_soft_dirty(old_pmd);
+ uffd_wp = pmd_uffd_wp(old_pmd);
}
VM_BUG_ON_PAGE(!page_count(page), page);
page_ref_add(page, HPAGE_PMD_NR - 1);
@@ -2261,6 +2330,8 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
entry = swp_entry_to_pte(swp_entry);
if (soft_dirty)
entry = pte_swp_mksoft_dirty(entry);
+ if (uffd_wp)
+ entry = pte_swp_mkuffd_wp(entry);
} else {
entry = mk_pte(page + i, READ_ONCE(vma->vm_page_prot));
entry = maybe_mkwrite(entry, vma);
@@ -2270,6 +2341,8 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
entry = pte_mkold(entry);
if (soft_dirty)
entry = pte_mksoft_dirty(entry);
+ if (uffd_wp)
+ entry = pte_mkuffd_wp(entry);
}
pte = pte_offset_map(&_pmd, addr);
BUG_ON(!pte_none(*pte));
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.