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: "