[PATCH 19/35] mm/mmap: Add shadow stack pages to memory accounting
From: Rick Edgecombe <rick.p.edgecombe@intel.com>
Date: 2022-01-30 21:24:38
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
From: Yu-cheng Yu <redacted> Account shadow stack pages to stack memory. Signed-off-by: Yu-cheng Yu <redacted> Reviewed-by: Kirill A. Shutemov <redacted> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Kees Cook <redacted> --- Yu-cheng v26: - Remove redundant #ifdef CONFIG_MMU. Yu-cheng v25: - Remove #ifdef CONFIG_ARCH_HAS_SHADOW_STACK for is_shadow_stack_mapping(). Yu-cheng v24: - Change arch_shadow_stack_mapping() to is_shadow_stack_mapping(). - Change VM_SHSTK to VM_SHADOW_STACK. arch/x86/include/asm/pgtable.h | 3 +++ arch/x86/mm/pgtable.c | 5 +++++ include/linux/pgtable.h | 8 ++++++++ mm/mmap.c | 5 +++++ 4 files changed, 21 insertions(+)
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 36166bdd0b98..55641498485c 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h@@ -1666,6 +1666,9 @@ static inline bool arch_faults_on_old_pte(void) #define maybe_mkwrite maybe_mkwrite extern pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma); +#define is_shadow_stack_mapping is_shadow_stack_mapping +extern bool is_shadow_stack_mapping(vm_flags_t vm_flags); + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_PGTABLE_H */
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index c22c8e9c37e8..61a364b9ae0a 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c@@ -884,3 +884,8 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) #endif /* CONFIG_X86_64 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ + +bool is_shadow_stack_mapping(vm_flags_t vm_flags) +{ + return vm_flags & VM_SHADOW_STACK; +}
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index bc8713a76e03..21fdb1273571 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h@@ -911,6 +911,14 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, __ptep_modify_prot_commit(vma, addr, ptep, pte); } #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ + +#ifndef is_shadow_stack_mapping +static inline bool is_shadow_stack_mapping(vm_flags_t vm_flags) +{ + return false; +} +#endif + #endif /* CONFIG_MMU */ /*
diff --git a/mm/mmap.c b/mm/mmap.c
index 1e8fdb0b51ed..9bab326332af 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -1716,6 +1716,9 @@ 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; }
@@ -3345,6 +3348,8 @@ 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);
--
2.17.1