ARM64: dts: rockchip: enable the gt9xx touchscreen on rk3399-tb dts
[firefly-linux-kernel-4.4.55.git] / mm / mremap.c
index 463a25705ac6d4ca38fb202b30b2ccae9161ce5b..c25bc6268e46506dba0320d15bb5c2e7d3e079f3 100644 (file)
 #include <linux/swap.h>
 #include <linux/capability.h>
 #include <linux/fs.h>
+#include <linux/swapops.h>
 #include <linux/highmem.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/mmu_notifier.h>
 #include <linux/sched/sysctl.h>
+#include <linux/uaccess.h>
+#include <linux/mm-arch-hooks.h>
 
-#include <asm/uaccess.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
@@ -69,6 +71,21 @@ static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
        return pmd;
 }
 
+static pte_t move_soft_dirty_pte(pte_t pte)
+{
+       /*
+        * Set soft dirty bit so we can notice
+        * in userspace the ptes were moved.
+        */
+#ifdef CONFIG_MEM_SOFT_DIRTY
+       if (pte_present(pte))
+               pte = pte_mksoft_dirty(pte);
+       else if (is_swap_pte(pte))
+               pte = pte_swp_mksoft_dirty(pte);
+#endif
+       return pte;
+}
+
 static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
                unsigned long old_addr, unsigned long old_end,
                struct vm_area_struct *new_vma, pmd_t *new_pmd,
@@ -81,7 +98,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
        spinlock_t *old_ptl, *new_ptl;
 
        /*
-        * When need_rmap_locks is true, we take the i_mmap_mutex and anon_vma
+        * When need_rmap_locks is true, we take the i_mmap_rwsem and anon_vma
         * locks to ensure that rmap will always observe either the old or the
         * new ptes. This is the easiest way to avoid races with
         * truncate_pagecache(), page migration, etc...
@@ -101,7 +118,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
        if (need_rmap_locks) {
                if (vma->vm_file) {
                        mapping = vma->vm_file->f_mapping;
-                       mutex_lock(&mapping->i_mmap_mutex);
+                       i_mmap_lock_write(mapping);
                }
                if (vma->anon_vma) {
                        anon_vma = vma->anon_vma;
@@ -126,6 +143,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
                        continue;
                pte = ptep_get_and_clear(mm, old_addr, old_pte);
                pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
+               pte = move_soft_dirty_pte(pte);
                set_pte_at(mm, new_addr, new_pte, pte);
        }
 
@@ -137,7 +155,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
        if (anon_vma)
                anon_vma_unlock_write(anon_vma);
        if (mapping)
-               mutex_unlock(&mapping->i_mmap_mutex);
+               i_mmap_unlock_write(mapping);
 }
 
 #define LATENCY_LIMIT  (64 * PAGE_SIZE)
@@ -175,10 +193,18 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
                        break;
                if (pmd_trans_huge(*old_pmd)) {
                        int err = 0;
-                       if (extent == HPAGE_PMD_SIZE)
+                       if (extent == HPAGE_PMD_SIZE) {
+                               VM_BUG_ON_VMA(vma->vm_file || !vma->anon_vma,
+                                             vma);
+                               /* See comment in move_ptes() */
+                               if (need_rmap_locks)
+                                       anon_vma_lock_write(vma->anon_vma);
                                err = move_huge_pmd(vma, new_vma, old_addr,
                                                    new_addr, old_end,
                                                    old_pmd, new_pmd);
+                               if (need_rmap_locks)
+                                       anon_vma_unlock_write(vma->anon_vma);
+                       }
                        if (err > 0) {
                                need_flush = true;
                                continue;
@@ -250,6 +276,12 @@ static unsigned long move_vma(struct vm_area_struct *vma,
        moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len,
                                     need_rmap_locks);
        if (moved_len < old_len) {
+               err = -ENOMEM;
+       } else if (vma->vm_ops && vma->vm_ops->mremap) {
+               err = vma->vm_ops->mremap(new_vma);
+       }
+
+       if (unlikely(err)) {
                /*
                 * On error, move entries back from new area to old,
                 * which will succeed since page tables still there,
@@ -260,7 +292,10 @@ static unsigned long move_vma(struct vm_area_struct *vma,
                vma = new_vma;
                old_len = new_len;
                old_addr = new_addr;
-               new_addr = -ENOMEM;
+               new_addr = err;
+       } else {
+               arch_remap(mm, old_addr, old_addr + old_len,
+                          new_addr, new_addr + new_len);
        }
 
        /* Conceal VM_ACCOUNT so old reservation is not undone */
@@ -311,28 +346,29 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 {
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma = find_vma(mm, addr);
+       unsigned long pgoff;
 
        if (!vma || vma->vm_start > addr)
-               goto Efault;
+               return ERR_PTR(-EFAULT);
 
        if (is_vm_hugetlb_page(vma))
-               goto Einval;
+               return ERR_PTR(-EINVAL);
 
        /* We can't remap across vm area boundaries */
        if (old_len > vma->vm_end - addr)
-               goto Efault;
+               return ERR_PTR(-EFAULT);
+
+       if (new_len == old_len)
+               return vma;
 
        /* Need to be careful about a growing mapping */
-       if (new_len > old_len) {
-               unsigned long pgoff;
-
-               if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
-                       goto Efault;
-               pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
-               pgoff += vma->vm_pgoff;
-               if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
-                       goto Einval;
-       }
+       pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+       pgoff += vma->vm_pgoff;
+       if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
+               return ERR_PTR(-EINVAL);
+
+       if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
+               return ERR_PTR(-EFAULT);
 
        if (vma->vm_flags & VM_LOCKED) {
                unsigned long locked, lock_limit;
@@ -340,29 +376,20 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
                lock_limit = rlimit(RLIMIT_MEMLOCK);
                locked += new_len - old_len;
                if (locked > lock_limit && !capable(CAP_IPC_LOCK))
-                       goto Eagain;
+                       return ERR_PTR(-EAGAIN);
        }
 
        if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT))
-               goto Enomem;
+               return ERR_PTR(-ENOMEM);
 
        if (vma->vm_flags & VM_ACCOUNT) {
                unsigned long charged = (new_len - old_len) >> PAGE_SHIFT;
                if (security_vm_enough_memory_mm(mm, charged))
-                       goto Efault;
+                       return ERR_PTR(-ENOMEM);
                *p = charged;
        }
 
        return vma;
-
-Efault:        /* very odd choice for most of the cases, but... */
-       return ERR_PTR(-EFAULT);
-Einval:
-       return ERR_PTR(-EINVAL);
-Enomem:
-       return ERR_PTR(-ENOMEM);
-Eagain:
-       return ERR_PTR(-EAGAIN);
 }
 
 static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
@@ -374,19 +401,14 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
        unsigned long charged = 0;
        unsigned long map_flags;
 
-       if (new_addr & ~PAGE_MASK)
+       if (offset_in_page(new_addr))
                goto out;
 
        if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
                goto out;
 
-       /* Check if the location we're moving into overlaps the
-        * old location at all, and fail if it does.
-        */
-       if ((new_addr <= addr) && (new_addr+new_len) > addr)
-               goto out;
-
-       if ((addr <= new_addr) && (addr+old_len) > new_addr)
+       /* Ensure the old/new locations do not overlap */
+       if (addr + old_len > new_addr && new_addr + new_len > addr)
                goto out;
 
        ret = do_munmap(mm, new_addr, new_len);
@@ -413,11 +435,11 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
        ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
                                ((addr - vma->vm_start) >> PAGE_SHIFT),
                                map_flags);
-       if (ret & ~PAGE_MASK)
+       if (offset_in_page(ret))
                goto out1;
 
        ret = move_vma(vma, addr, old_len, new_len, new_addr, locked);
-       if (!(ret & ~PAGE_MASK))
+       if (!(offset_in_page(ret)))
                goto out;
 out1:
        vm_unacct_memory(charged);
@@ -456,13 +478,14 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
        unsigned long charged = 0;
        bool locked = false;
 
-       down_write(&current->mm->mmap_sem);
-
        if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
-               goto out;
+               return ret;
 
-       if (addr & ~PAGE_MASK)
-               goto out;
+       if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
+               return ret;
+
+       if (offset_in_page(addr))
+               return ret;
 
        old_len = PAGE_ALIGN(old_len);
        new_len = PAGE_ALIGN(new_len);
@@ -473,12 +496,13 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
         * a zero new-len is nonsensical.
         */
        if (!new_len)
-               goto out;
+               return ret;
+
+       down_write(&current->mm->mmap_sem);
 
        if (flags & MREMAP_FIXED) {
-               if (flags & MREMAP_MAYMOVE)
-                       ret = mremap_to(addr, old_len, new_addr, new_len,
-                                       &locked);
+               ret = mremap_to(addr, old_len, new_addr, new_len,
+                               &locked);
                goto out;
        }
 
@@ -542,7 +566,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                                        vma->vm_pgoff +
                                        ((addr - vma->vm_start) >> PAGE_SHIFT),
                                        map_flags);
-               if (new_addr & ~PAGE_MASK) {
+               if (offset_in_page(new_addr)) {
                        ret = new_addr;
                        goto out;
                }
@@ -550,8 +574,10 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
        }
 out:
-       if (ret & ~PAGE_MASK)
+       if (offset_in_page(ret)) {
                vm_unacct_memory(charged);
+               locked = 0;
+       }
        up_write(&current->mm->mmap_sem);
        if (locked && new_len > old_len)
                mm_populate(new_addr + old_len, new_len - old_len);