Re: [PATCH v2 19/39] mm/mmap: Add shadow stack pages to memory accounting

From: Yu-cheng Yu <redacted>

Account shadow stack pages to stack memory.

Signed-off-by: Yu-cheng Yu <redacted>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Kees Cook <redacted>

---

v2:
 - Remove is_shadow_stack_mapping() and just change it to directly bitwise
   and VM_SHADOW_STACK.

Yu-cheng v26:
 - Remove redundant #ifdef CONFIG_MMU.

Yu-cheng v25:
 - Remove #ifdef CONFIG_ARCH_HAS_SHADOW_STACK for is_shadow_stack_mapping().

 mm/mmap.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/mmap.c b/mm/mmap.c
index f0d2e9143bd0..8569ef09614c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c

@@ -1682,6 +1682,9 @@ static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
 	if (file && is_file_hugepages(file))
 		return 0;
 
+	if (vm_flags & VM_SHADOW_STACK)
+		return 1;
+
 	return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;