[RFC PATCH v4 23/27] mm/map: Add Shadow stack pages to memory accounting

Yu-cheng Yu
2018-09-21T15:12:03Z

Add shadow stack pages to memory accounting.
Also check if the system has enough memory before enabling CET.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu.intel.com>
---
mm/mmap.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/mm/mmap.c b/mm/mmap.c
index 5f2b2b184c60..de2d0faa1c61 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1671,6 +1671,9 @@ static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
if (file && is_file_hugepages(file))
return 0;

+ if (arch_copy_pte_mapping(vm_flags))
+ return 1;
+
return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
}

@@ -3261,6 +3264,8 @@ void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, long npages)
mm->stack_vm += npages;
else if (is_data_mapping(flags))
mm->data_vm += npages;
+ else if (arch_copy_pte_mapping(flags))
+ mm->data_vm += npages;
}

static vm_fault_t special_mapping_fault(struct vm_fault *vmf);
--
2.17.1