Merge branch 'linus' into irq/genirq

1 files changed, 54 insertions, 8 deletions

diff --git a/mm/mlock.c b/mm/mlock.c
index 1ada366570c..2904a347e47 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -173,12 +173,13 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
 		  (atomic_read(&mm->mm_users) != 0));
 
 	/*
-	 * mlock:   don't page populate if page has PROT_NONE permission.
-	 * munlock: the pages always do munlock althrough
-	 *          its has PROT_NONE permission.
+	 * mlock:   don't page populate if vma has PROT_NONE permission.
+	 * munlock: always do munlock although the vma has PROT_NONE
+	 *          permission, or SIGKILL is pending.
 	 */
 	if (!mlock)
-		gup_flags |= GUP_FLAGS_IGNORE_VMA_PERMISSIONS;
+		gup_flags |= GUP_FLAGS_IGNORE_VMA_PERMISSIONS |
+			     GUP_FLAGS_IGNORE_SIGKILL;
 
 	if (vma->vm_flags & VM_WRITE)
 		gup_flags |= GUP_FLAGS_WRITE;
@@ -529,7 +530,7 @@ static int do_mlock(unsigned long start, size_t len, int on)
 	return error;
 }
 
-asmlinkage long sys_mlock(unsigned long start, size_t len)
+SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
 {
 	unsigned long locked;
 	unsigned long lock_limit;
@@ -557,7 +558,7 @@ asmlinkage long sys_mlock(unsigned long start, size_t len)
 	return error;
 }
 
-asmlinkage long sys_munlock(unsigned long start, size_t len)
+SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
 {
 	int ret;
 
@@ -594,7 +595,7 @@ out:
 	return 0;
 }
 
-asmlinkage long sys_mlockall(int flags)
+SYSCALL_DEFINE1(mlockall, int, flags)
 {
 	unsigned long lock_limit;
 	int ret = -EINVAL;
@@ -622,7 +623,7 @@ out:
 	return ret;
 }
 
-asmlinkage long sys_munlockall(void)
+SYSCALL_DEFINE0(munlockall)
 {
 	int ret;
 
@@ -667,3 +668,48 @@ void user_shm_unlock(size_t size, struct user_struct *user)
 	spin_unlock(&shmlock_user_lock);
 	free_uid(user);
 }
+
+void *alloc_locked_buffer(size_t size)
+{
+	unsigned long rlim, vm, pgsz;
+	void *buffer = NULL;
+
+	pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	down_write(&current->mm->mmap_sem);
+
+	rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+	vm   = current->mm->total_vm + pgsz;
+	if (rlim < vm)
+		goto out;
+
+	rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+	vm   = current->mm->locked_vm + pgsz;
+	if (rlim < vm)
+		goto out;
+
+	buffer = kzalloc(size, GFP_KERNEL);
+	if (!buffer)
+		goto out;
+
+	current->mm->total_vm  += pgsz;
+	current->mm->locked_vm += pgsz;
+
+ out:
+	up_write(&current->mm->mmap_sem);
+	return buffer;
+}
+
+void free_locked_buffer(void *buffer, size_t size)
+{
+	unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	down_write(&current->mm->mmap_sem);
+
+	current->mm->total_vm  -= pgsz;
+	current->mm->locked_vm -= pgsz;
+
+	up_write(&current->mm->mmap_sem);
+
+	kfree(buffer);
+}