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Diffstat (limited to 'mm')
-rw-r--r--mm/secretmem.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/mm/secretmem.c b/mm/secretmem.c
index 972cd1bbc3cc..f77d25467a14 100644
--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -40,6 +40,13 @@ module_param_named(enable, secretmem_enable, bool, 0400);
MODULE_PARM_DESC(secretmem_enable,
"Enable secretmem and memfd_secret(2) system call");
+static atomic_t secretmem_users;
+
+bool secretmem_active(void)
+{
+ return !!atomic_read(&secretmem_users);
+}
+
static vm_fault_t secretmem_fault(struct vm_fault *vmf)
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
@@ -94,6 +101,12 @@ static const struct vm_operations_struct secretmem_vm_ops = {
.fault = secretmem_fault,
};
+static int secretmem_release(struct inode *inode, struct file *file)
+{
+ atomic_dec(&secretmem_users);
+ return 0;
+}
+
static int secretmem_mmap(struct file *file, struct vm_area_struct *vma)
{
unsigned long len = vma->vm_end - vma->vm_start;
@@ -116,6 +129,7 @@ bool vma_is_secretmem(struct vm_area_struct *vma)
}
static const struct file_operations secretmem_fops = {
+ .release = secretmem_release,
.mmap = secretmem_mmap,
};
@@ -202,6 +216,7 @@ SYSCALL_DEFINE1(memfd_secret, unsigned int, flags)
file->f_flags |= O_LARGEFILE;
fd_install(fd, file);
+ atomic_inc(&secretmem_users);
return fd;
err_put_fd: