Account shadow stack pages to stack memory.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
v24:
- Change arch_shadow_stack_mapping() to is_shadow_stack_mapping().
- Change VM_SHSTK to VM_SHADOW_STACK.
arch/x86/mm/pgtable.c | 7 +++++++
include/linux/pgtable.h | 11 +++++++++++
mm/mmap.c | 5 +++++
3 files changed, 23 insertions(+)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index e778dbbef3d8..212a8c1fe5ba 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -897,3 +897,10 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
#endif /* CONFIG_X86_64 */
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+#ifdef CONFIG_ARCH_HAS_SHADOW_STACK
+bool is_shadow_stack_mapping(vm_flags_t vm_flags)
+{
+ return (vm_flags & VM_SHADOW_STACK);
+}
+#endif
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 5e772392a379..0070a6d5c272 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1446,6 +1446,17 @@ static inline bool arch_has_pfn_modify_check(void)
}
#endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
+#ifdef CONFIG_MMU
+#ifdef CONFIG_ARCH_HAS_SHADOW_STACK
+bool is_shadow_stack_mapping(vm_flags_t vm_flags);
+#else
+static inline bool is_shadow_stack_mapping(vm_flags_t vm_flags)
+{
+ return false;
+}
+#endif /* CONFIG_ARCH_HAS_SHADOW_STACK */
+#endif /* CONFIG_MMU */
+
/*
* Architecture PAGE_KERNEL_* fallbacks
*
diff --git a/mm/mmap.c b/mm/mmap.c
index 3f287599a7a3..d77fb39b6ab5 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1718,6 +1718,9 @@ static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
if (file && is_file_hugepages(file))
return 0;
+ if (is_shadow_stack_mapping(vm_flags))
+ return 1;
+
return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
}
@@ -3387,6 +3390,8 @@ 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 (is_shadow_stack_mapping(flags))
+ mm->stack_vm += npages;
}
static vm_fault_t special_mapping_fault(struct vm_fault *vmf);
--
2.21.0
