X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?p=kvmfornfv.git;a=blobdiff_plain;f=kernel%2Fmm%2Fmremap.c;h=c25bc6268e46506dba0320d15bb5c2e7d3e079f3;hp=034e2d3606522bf2a3b550c93052b6bf11278851;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hpb=f93b97fd65072de626c074dbe099a1fff05ce060

diff --git a/kernel/mm/mremap.c b/kernel/mm/mremap.c
index 034e2d360..c25bc6268 100644
--- a/kernel/mm/mremap.c
+++ b/kernel/mm/mremap.c
@@ -22,6 +22,7 @@
 #include <linux/mmu_notifier.h>
 #include <linux/sched/sysctl.h>
 #include <linux/uaccess.h>
+#include <linux/mm-arch-hooks.h>
 
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
@@ -275,6 +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,
@@ -285,14 +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;
-	} else if (vma->vm_file && vma->vm_file->f_op->mremap) {
-		err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
-		if (err < 0) {
-			move_page_tables(new_vma, new_addr, vma, old_addr,
-					 moved_len, true);
-			return err;
-		}
+		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 */
@@ -343,6 +346,7 @@ 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)
 		return ERR_PTR(-EFAULT);
@@ -354,17 +358,17 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 	if (old_len > vma->vm_end - addr)
 		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))
-			return ERR_PTR(-EFAULT);
-		pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
-		pgoff += vma->vm_pgoff;
-		if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
-			return ERR_PTR(-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;
@@ -397,19 +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);
@@ -436,11 +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);
@@ -485,7 +484,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 	if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
 		return ret;
 
-	if (addr & ~PAGE_MASK)
+	if (offset_in_page(addr))
 		return ret;
 
 	old_len = PAGE_ALIGN(old_len);
@@ -567,7 +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;
 		}
@@ -575,8 +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);