diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/Makefile | 2 | ||||
| -rw-r--r-- | mm/backing-dev.c | 35 | ||||
| -rw-r--r-- | mm/fremap.c | 283 | ||||
| -rw-r--r-- | mm/memory.c | 3 | ||||
| -rw-r--r-- | mm/mmap.c | 114 | ||||
| -rw-r--r-- | mm/mprotect.c | 20 | ||||
| -rw-r--r-- | mm/nommu.c | 8 |
7 files changed, 140 insertions, 325 deletions
diff --git a/mm/Makefile b/mm/Makefile index 1f534a7f0a71..ca7a8c4f03d4 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -3,7 +3,7 @@ # mmu-y := nommu.o -mmu-$(CONFIG_MMU) := fremap.o gup.o highmem.o memory.o mincore.o \ +mmu-$(CONFIG_MMU) := gup.o highmem.o memory.o mincore.o \ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ vmalloc.o pagewalk.o pgtable-generic.o diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 0ae0df55000b..06715eb66bff 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -234,11 +234,46 @@ static ssize_t stable_pages_required_show(struct device *dev, } static DEVICE_ATTR_RO(stable_pages_required); +static ssize_t strictlimit_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + unsigned int val; + ssize_t ret; + + ret = kstrtouint(buf, 10, &val); + if (ret < 0) + return ret; + + switch (val) { + case 0: + bdi->capabilities &= ~BDI_CAP_STRICTLIMIT; + break; + case 1: + bdi->capabilities |= BDI_CAP_STRICTLIMIT; + break; + default: + return -EINVAL; + } + + return count; +} +static ssize_t strictlimit_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + + return snprintf(page, PAGE_SIZE-1, "%d\n", + !!(bdi->capabilities & BDI_CAP_STRICTLIMIT)); +} +static DEVICE_ATTR_RW(strictlimit); + static struct attribute *bdi_dev_attrs[] = { &dev_attr_read_ahead_kb.attr, &dev_attr_min_ratio.attr, &dev_attr_max_ratio.attr, &dev_attr_stable_pages_required.attr, + &dev_attr_strictlimit.attr, NULL, }; ATTRIBUTE_GROUPS(bdi_dev); diff --git a/mm/fremap.c b/mm/fremap.c deleted file mode 100644 index 72b8fa361433..000000000000 --- a/mm/fremap.c +++ /dev/null @@ -1,283 +0,0 @@ -/* - * linux/mm/fremap.c - * - * Explicit pagetable population and nonlinear (random) mappings support. - * - * started by Ingo Molnar, Copyright (C) 2002, 2003 - */ -#include <linux/export.h> -#include <linux/backing-dev.h> -#include <linux/mm.h> -#include <linux/swap.h> -#include <linux/file.h> -#include <linux/mman.h> -#include <linux/pagemap.h> -#include <linux/swapops.h> -#include <linux/rmap.h> -#include <linux/syscalls.h> -#include <linux/mmu_notifier.h> - -#include <asm/mmu_context.h> -#include <asm/cacheflush.h> -#include <asm/tlbflush.h> - -#include "internal.h" - -static int mm_counter(struct page *page) -{ - return PageAnon(page) ? MM_ANONPAGES : MM_FILEPAGES; -} - -static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) -{ - pte_t pte = *ptep; - struct page *page; - swp_entry_t entry; - - if (pte_present(pte)) { - flush_cache_page(vma, addr, pte_pfn(pte)); - pte = ptep_clear_flush(vma, addr, ptep); - page = vm_normal_page(vma, addr, pte); - if (page) { - if (pte_dirty(pte)) - set_page_dirty(page); - update_hiwater_rss(mm); - dec_mm_counter(mm, mm_counter(page)); - page_remove_rmap(page); - page_cache_release(page); - } - } else { /* zap_pte() is not called when pte_none() */ - if (!pte_file(pte)) { - update_hiwater_rss(mm); - entry = pte_to_swp_entry(pte); - if (non_swap_entry(entry)) { - if (is_migration_entry(entry)) { - page = migration_entry_to_page(entry); - dec_mm_counter(mm, mm_counter(page)); - } - } else { - free_swap_and_cache(entry); - dec_mm_counter(mm, MM_SWAPENTS); - } - } - pte_clear_not_present_full(mm, addr, ptep, 0); - } -} - -/* - * Install a file pte to a given virtual memory address, release any - * previously existing mapping. - */ -static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, unsigned long pgoff, pgprot_t prot) -{ - int err = -ENOMEM; - pte_t *pte, ptfile; - spinlock_t *ptl; - - pte = get_locked_pte(mm, addr, &ptl); - if (!pte) - goto out; - - ptfile = pgoff_to_pte(pgoff); - - if (!pte_none(*pte)) - zap_pte(mm, vma, addr, pte); - - set_pte_at(mm, addr, pte, pte_file_mksoft_dirty(ptfile)); - /* - * We don't need to run update_mmu_cache() here because the "file pte" - * being installed by install_file_pte() is not a real pte - it's a - * non-present entry (like a swap entry), noting what file offset should - * be mapped there when there's a fault (in a non-linear vma where - * that's not obvious). - */ - pte_unmap_unlock(pte, ptl); - err = 0; -out: - return err; -} - -int generic_file_remap_pages(struct vm_area_struct *vma, unsigned long addr, - unsigned long size, pgoff_t pgoff) -{ - struct mm_struct *mm = vma->vm_mm; - int err; - - do { - err = install_file_pte(mm, vma, addr, pgoff, vma->vm_page_prot); - if (err) - return err; - - size -= PAGE_SIZE; - addr += PAGE_SIZE; - pgoff++; - } while (size); - - return 0; -} -EXPORT_SYMBOL(generic_file_remap_pages); - -/** - * sys_remap_file_pages - remap arbitrary pages of an existing VM_SHARED vma - * @start: start of the remapped virtual memory range - * @size: size of the remapped virtual memory range - * @prot: new protection bits of the range (see NOTE) - * @pgoff: to-be-mapped page of the backing store file - * @flags: 0 or MAP_NONBLOCKED - the later will cause no IO. - * - * sys_remap_file_pages remaps arbitrary pages of an existing VM_SHARED vma - * (shared backing store file). - * - * This syscall works purely via pagetables, so it's the most efficient - * way to map the same (large) file into a given virtual window. Unlike - * mmap()/mremap() it does not create any new vmas. The new mappings are - * also safe across swapout. - * - * NOTE: the @prot parameter right now is ignored (but must be zero), - * and the vma's default protection is used. Arbitrary protections - * might be implemented in the future. - */ -SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, - unsigned long, prot, unsigned long, pgoff, unsigned long, flags) -{ - struct mm_struct *mm = current->mm; - struct address_space *mapping; - struct vm_area_struct *vma; - int err = -EINVAL; - int has_write_lock = 0; - vm_flags_t vm_flags = 0; - - pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. " - "See Documentation/vm/remap_file_pages.txt.\n", - current->comm, current->pid); - - if (prot) - return err; - /* - * Sanitize the syscall parameters: - */ - start = start & PAGE_MASK; - size = size & PAGE_MASK; - - /* Does the address range wrap, or is the span zero-sized? */ - if (start + size <= start) - return err; - - /* Does pgoff wrap? */ - if (pgoff + (size >> PAGE_SHIFT) < pgoff) - return err; - - /* Can we represent this offset inside this architecture's pte's? */ -#if PTE_FILE_MAX_BITS < BITS_PER_LONG - if (pgoff + (size >> PAGE_SHIFT) >= (1UL << PTE_FILE_MAX_BITS)) - return err; -#endif - - /* We need down_write() to change vma->vm_flags. */ - down_read(&mm->mmap_sem); - retry: - vma = find_vma(mm, start); - - /* - * Make sure the vma is shared, that it supports prefaulting, - * and that the remapped range is valid and fully within - * the single existing vma. - */ - if (!vma || !(vma->vm_flags & VM_SHARED)) - goto out; - - if (!vma->vm_ops || !vma->vm_ops->remap_pages) - goto out; - - if (start < vma->vm_start || start + size > vma->vm_end) - goto out; - - /* Must set VM_NONLINEAR before any pages are populated. */ - if (!(vma->vm_flags & VM_NONLINEAR)) { - /* - * vm_private_data is used as a swapout cursor - * in a VM_NONLINEAR vma. - */ - if (vma->vm_private_data) - goto out; - - /* Don't need a nonlinear mapping, exit success */ - if (pgoff == linear_page_index(vma, start)) { - err = 0; - goto out; - } - - if (!has_write_lock) { -get_write_lock: - up_read(&mm->mmap_sem); - down_write(&mm->mmap_sem); - has_write_lock = 1; - goto retry; - } - mapping = vma->vm_file->f_mapping; - /* - * page_mkclean doesn't work on nonlinear vmas, so if - * dirty pages need to be accounted, emulate with linear - * vmas. - */ - if (mapping_cap_account_dirty(mapping)) { - unsigned long addr; - struct file *file = get_file(vma->vm_file); - /* mmap_region may free vma; grab the info now */ - vm_flags = vma->vm_flags; - - addr = mmap_region(file, start, size, vm_flags, pgoff); - fput(file); - if (IS_ERR_VALUE(addr)) { - err = addr; - } else { - BUG_ON(addr != start); - err = 0; - } - goto out_freed; - } - mutex_lock(&mapping->i_mmap_mutex); - flush_dcache_mmap_lock(mapping); - vma->vm_flags |= VM_NONLINEAR; - vma_interval_tree_remove(vma, &mapping->i_mmap); - vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear); - flush_dcache_mmap_unlock(mapping); - mutex_unlock(&mapping->i_mmap_mutex); - } - - if (vma->vm_flags & VM_LOCKED) { - /* - * drop PG_Mlocked flag for over-mapped range - */ - if (!has_write_lock) - goto get_write_lock; - vm_flags = vma->vm_flags; - munlock_vma_pages_range(vma, start, start + size); - vma->vm_flags = vm_flags; - } - - mmu_notifier_invalidate_range_start(mm, start, start + size); - err = vma->vm_ops->remap_pages(vma, start, size, pgoff); - mmu_notifier_invalidate_range_end(mm, start, start + size); - - /* - * We can't clear VM_NONLINEAR because we'd have to do - * it after ->populate completes, and that would prevent - * downgrading the lock. (Locks can't be upgraded). - */ - -out: - if (vma) - vm_flags = vma->vm_flags; -out_freed: - if (likely(!has_write_lock)) - up_read(&mm->mmap_sem); - else - up_write(&mm->mmap_sem); - if (!err && ((vm_flags & VM_LOCKED) || !(flags & MAP_NONBLOCK))) - mm_populate(start, size); - - return err; -} diff --git a/mm/memory.c b/mm/memory.c index caf2a4ee8daa..64f82aacb0ce 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2053,7 +2053,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, old_page = vm_normal_page(vma, address, orig_pte); if (!old_page) { /* - * VM_MIXEDMAP !pfn_valid() case + * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a + * VM_PFNMAP VMA. * * We should not cow pages in a shared writeable mapping. * Just mark the pages writable as we can't do any dirty diff --git a/mm/mmap.c b/mm/mmap.c index 93d28c7e5420..915661293af9 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -89,6 +89,25 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags) } EXPORT_SYMBOL(vm_get_page_prot); +static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags) +{ + return pgprot_modify(oldprot, vm_get_page_prot(vm_flags)); +} + +/* Update vma->vm_page_prot to reflect vma->vm_flags. */ +void vma_set_page_prot(struct vm_area_struct *vma) +{ + unsigned long vm_flags = vma->vm_flags; + + vma->vm_page_prot = vm_pgprot_modify(vma->vm_page_prot, vm_flags); + if (vma_wants_writenotify(vma)) { + vm_flags &= ~VM_SHARED; + vma->vm_page_prot = vm_pgprot_modify(vma->vm_page_prot, + vm_flags); + } +} + + int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */ int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */ unsigned long sysctl_overcommit_kbytes __read_mostly; @@ -1475,11 +1494,16 @@ int vma_wants_writenotify(struct vm_area_struct *vma) if (vma->vm_ops && vma->vm_ops->page_mkwrite) return 1; - /* The open routine did something to the protections already? */ + /* The open routine did something to the protections that pgprot_modify + * won't preserve? */ if (pgprot_val(vma->vm_page_prot) != - pgprot_val(vm_get_page_prot(vm_flags))) + pgprot_val(vm_pgprot_modify(vma->vm_page_prot, vm_flags))) return 0; + /* Do we need to track softdirty? */ + if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY)) + return 1; + /* Specialty mapping? */ if (vm_flags & VM_PFNMAP) return 0; @@ -1615,21 +1639,6 @@ munmap_back: goto free_vma; } - if (vma_wants_writenotify(vma)) { - pgprot_t pprot = vma->vm_page_prot; - - /* Can vma->vm_page_prot have changed?? - * - * Answer: Yes, drivers may have changed it in their - * f_op->mmap method. - * - * Ensures that vmas marked as uncached stay that way. - */ - vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED); - if (pgprot_val(pprot) == pgprot_val(pgprot_noncached(pprot))) - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - } - vma_link(mm, vma, prev, rb_link, rb_parent); /* Once vma denies write, undo our temporary denial count */ if (file) { @@ -1663,6 +1672,8 @@ out: */ vma->vm_flags |= VM_SOFTDIRTY; + vma_set_page_prot(vma); + return addr; unmap_and_free_vma: @@ -2610,6 +2621,75 @@ SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) return vm_munmap(addr, len); } + +/* + * Emulation of deprecated remap_file_pages() syscall. + */ +SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, + unsigned long, prot, unsigned long, pgoff, unsigned long, flags) +{ + + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + unsigned long populate = 0; + unsigned long ret = -EINVAL; + struct file *file; + + pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. " + "See Documentation/vm/remap_file_pages.txt.\n", + current->comm, current->pid); + + if (prot) + return ret; + start = start & PAGE_MASK; + size = size & PAGE_MASK; + + if (start + size <= start) + return ret; + + /* Does pgoff wrap? */ + if (pgoff + (size >> PAGE_SHIFT) < pgoff) + return ret; + + down_write(&mm->mmap_sem); + vma = find_vma(mm, start); + + if (!vma || !(vma->vm_flags & VM_SHARED)) + goto out; + + if (start < vma->vm_start || start + size > vma->vm_end) + goto out; + + if (pgoff == linear_page_index(vma, start)) { + ret = 0; + goto out; + } + + prot |= vma->vm_flags & VM_READ ? PROT_READ : 0; + prot |= vma->vm_flags & VM_WRITE ? PROT_WRITE : 0; + prot |= vma->vm_flags & VM_EXEC ? PROT_EXEC : 0; + + flags &= MAP_NONBLOCK; + flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE; + if (vma->vm_flags & VM_LOCKED) { + flags |= MAP_LOCKED; + /* drop PG_Mlocked flag for over-mapped range */ + munlock_vma_pages_range(vma, start, start + size); + } + + file = get_file(vma->vm_file); + ret = do_mmap_pgoff(vma->vm_file, start, size, + prot, flags, pgoff, &populate); + fput(file); +out: + up_write(&mm->mmap_sem); + if (populate) + mm_populate(ret, populate); + if (!IS_ERR_VALUE(ret)) + ret = 0; + return ret; +} + static inline void verify_mm_writelocked(struct mm_struct *mm) { #ifdef CONFIG_DEBUG_VM diff --git a/mm/mprotect.c b/mm/mprotect.c index c43d557941f8..ace93454ce8e 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -29,13 +29,6 @@ #include <asm/cacheflush.h> #include <asm/tlbflush.h> -#ifndef pgprot_modify -static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) -{ - return newprot; -} -#endif - /* * For a prot_numa update we only hold mmap_sem for read so there is a * potential race with faulting where a pmd was temporarily none. This @@ -93,7 +86,9 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, * Avoid taking write faults for pages we * know to be dirty. */ - if (dirty_accountable && pte_dirty(ptent)) + if (dirty_accountable && pte_dirty(ptent) && + (pte_soft_dirty(ptent) || + !(vma->vm_flags & VM_SOFTDIRTY))) ptent = pte_mkwrite(ptent); ptep_modify_prot_commit(mm, addr, pte, ptent); updated = true; @@ -320,13 +315,8 @@ success: * held in write mode. */ vma->vm_flags = newflags; - vma->vm_page_prot = pgprot_modify(vma->vm_page_prot, - vm_get_page_prot(newflags)); - - if (vma_wants_writenotify(vma)) { - vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED); - dirty_accountable = 1; - } + dirty_accountable = vma_wants_writenotify(vma); + vma_set_page_prot(vma); change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable, 0); diff --git a/mm/nommu.c b/mm/nommu.c index bd1808e194a7..bd10aa18384c 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1994,14 +1994,6 @@ void filemap_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf) } EXPORT_SYMBOL(filemap_map_pages); -int generic_file_remap_pages(struct vm_area_struct *vma, unsigned long addr, - unsigned long size, pgoff_t pgoff) -{ - BUG(); - return 0; -} -EXPORT_SYMBOL(generic_file_remap_pages); - static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, unsigned long addr, void *buf, int len, int write) { |