[PATCH v24 18/30] mm/mmap: Add shadow stack pages to memory accounting
From: Yu-cheng Yu <hidden>
Date: 2021-04-01 22:12:38
Also in:
linux-arch, linux-doc, linux-mm, lkml
Subsystem:
memory management, memory management - core, memory mapping, the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
Account shadow stack pages to stack memory. Signed-off-by: Yu-cheng Yu <redacted> Cc: Kees Cook <redacted> Cc: Kirill A. Shutemov <redacted> --- 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