VM: add "vm_munmap()" helper function

Like the vm_brk() function, this is the same as "do_munmap()", except it
does the VM locking for the caller.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 5 insertions, 17 deletions

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index 9d0fd7d5bb82..2777310b698b 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -605,9 +605,9 @@ pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
 }
 
 static inline unsigned int
-pfm_do_munmap(struct mm_struct *mm, unsigned long addr, size_t len, int acct)
+pfm_vm_munmap(struct mm_struct *mm, unsigned long addr, size_t len)
 {
-	return do_munmap(mm, addr, len);
+	return vm_munmap(mm, addr, len);
 }
 
 static inline unsigned long 
@@ -1473,13 +1473,8 @@ pfm_remove_smpl_mapping(struct task_struct *task, void *vaddr, unsigned long siz
 	/*
 	 * does the actual unmapping
 	 */
-	down_write(&task->mm->mmap_sem);
-
-	DPRINT(("down_write done smpl_vaddr=%p size=%lu\n", vaddr, size));
+	r = pfm_vm_munmap(task->mm, (unsigned long)vaddr, size);
 
-	r = pfm_do_munmap(task->mm, (unsigned long)vaddr, size, 0);
-
-	up_write(&task->mm->mmap_sem);
 	if (r !=0) {
 		printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
 	}
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index 232df9949530..022e57aadf5d 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -566,15 +566,10 @@ out:
 
 SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
 {
-	long ret;
-
 	if (invalid_64bit_range(addr, len))
 		return -EINVAL;
 
-	down_write(&current->mm->mmap_sem);
-	ret = do_munmap(current->mm, addr, len);
-	up_write(&current->mm->mmap_sem);
-	return ret;
+	return vm_munmap(current->mm, addr, len);
 }
 
 extern unsigned long do_mremap(unsigned long addr,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4044ce0bf7c1..8beb9ce79364 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6366,10 +6366,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 	if (!user_alloc && !old.user_alloc && old.rmap && !npages) {
 		int ret;
 
-		down_write(&current->mm->mmap_sem);
-		ret = do_munmap(current->mm, old.userspace_addr,
+		ret = vm_munmap(current->mm, old.userspace_addr,
 				old.npages * PAGE_SIZE);
-		up_write(&current->mm->mmap_sem);
 		if (ret < 0)
 			printk(KERN_WARNING
 			       "kvm_vm_ioctl_set_memory_region: "