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>

8 files changed, 25 insertions, 33 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: "
diff --git a/drivers/gpu/drm/i810/i810_dma.c b/drivers/gpu/drm/i810/i810_dma.c
index 2c8a60c3b98e..b85337f06fbf 100644
--- a/drivers/gpu/drm/i810/i810_dma.c
+++ b/drivers/gpu/drm/i810/i810_dma.c
@@ -157,11 +157,9 @@ static int i810_unmap_buffer(struct drm_buf *buf)
         if (buf_priv->currently_mapped != I810_BUF_MAPPED)
                 return -EINVAL;
 
-        down_write(&current->mm->mmap_sem);
-        retcode = do_munmap(current->mm,
+        retcode = vm_munmap(current->mm,
                             (unsigned long)buf_priv->virtual,
                             (size_t) buf->total);
-        up_write(&current->mm->mmap_sem);
 
         buf_priv->currently_mapped = I810_BUF_UNMAPPED;
         buf_priv->virtual = NULL;
diff --git a/fs/aio.c b/fs/aio.c
index da887604dfc5..99bd790e8cd2 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -92,11 +92,8 @@ static void aio_free_ring(struct kioctx *ctx)
         for (i=0; i<info->nr_pages; i++)
                 put_page(info->ring_pages[i]);
 
-        if (info->mmap_size) {
-                down_write(&ctx->mm->mmap_sem);
-                do_munmap(ctx->mm, info->mmap_base, info->mmap_size);
-                up_write(&ctx->mm->mmap_sem);
-        }
+        if (info->mmap_size)
+                vm_munmap(ctx->mm, info->mmap_base, info->mmap_size);
 
         if (info->ring_pages && info->ring_pages != info->internal_pages)
                 kfree(info->ring_pages);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index bfee4ad6680b..cb61950a3aa1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1417,6 +1417,7 @@ extern int do_munmap(struct mm_struct *, unsigned long, size_t);
 
 /* These take the mm semaphore themselves */
 extern unsigned long vm_brk(unsigned long, unsigned long);
+extern int vm_munmap(struct mm_struct *, unsigned long, size_t);
 
 /* truncate.c */
 extern void truncate_inode_pages(struct address_space *, loff_t);
diff --git a/mm/mmap.c b/mm/mmap.c
index df51891c8646..4af45f519f19 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2107,21 +2107,24 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
 
         return 0;
 }
-
 EXPORT_SYMBOL(do_munmap);
 
-SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+int vm_munmap(struct mm_struct *mm, unsigned long start, size_t len)
 {
         int ret;
-        struct mm_struct *mm = current->mm;
-
-        profile_munmap(addr);
 
         down_write(&mm->mmap_sem);
-        ret = do_munmap(mm, addr, len);
+        ret = do_munmap(mm, start, len);
         up_write(&mm->mmap_sem);
         return ret;
 }
+EXPORT_SYMBOL(vm_munmap);
+
+SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+{
+        profile_munmap(addr);
+        return vm_munmap(current->mm, addr, len);
+}
 
 static inline void verify_mm_writelocked(struct mm_struct *mm)
 {
diff --git a/mm/nommu.c b/mm/nommu.c
index 634193324a6b..11a69b22bd4b 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1709,16 +1709,21 @@ erase_whole_vma:
 }
 EXPORT_SYMBOL(do_munmap);
 
-SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+int vm_munmap(struct mm_struct *mm, unsigned long addr, size_t len)
 {
         int ret;
-        struct mm_struct *mm = current->mm;
 
         down_write(&mm->mmap_sem);
         ret = do_munmap(mm, addr, len);
         up_write(&mm->mmap_sem);
         return ret;
 }
+EXPORT_SYMBOL(vm_munmap);
+
+SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+{
+        return vm_munmap(current->mm, addr, len);
+}
 
 /*
  * release all the mappings made in a process's VM space