[PATCH v20 17/25] mm/mmap: Add shadow stack pages to memory accounting
STALE2055d
REVIEWED: 1 (0M)
From: Yu-cheng Yu <hidden>
Date: 2021-02-10 18:19:00
Also in:
linux-api, linux-arch, 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
Revision v20 of 26 in this series; 1 review trailer.
Revisions (26)
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Account shadow stack pages to stack memory. Signed-off-by: Yu-cheng Yu <redacted> Reviewed-by: Kees Cook <redacted> --- 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 0f4fbf51a9fc..948d28c29964 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c@@ -895,3 +895,10 @@ 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 arch_shadow_stack_mapping(vm_flags_t vm_flags) +{ + return (vm_flags & VM_SHSTK); +} +#endif
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index d8452218d09b..b888b246b8b1 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h@@ -1463,6 +1463,17 @@ static inline pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma #endif /* CONFIG_ARCH_MAYBE_MKWRITE */ #endif /* CONFIG_MMU */ +#ifdef CONFIG_MMU +#ifdef CONFIG_ARCH_HAS_SHADOW_STACK +bool arch_shadow_stack_mapping(vm_flags_t vm_flags); +#else +static inline bool arch_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 dc7206032387..51200b821898 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -1720,6 +1720,9 @@ static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags) if (file && is_file_hugepages(file)) return 0; + if (arch_shadow_stack_mapping(vm_flags)) + return 1; + return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE; }
@@ -3389,6 +3392,8 @@ 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_shadow_stack_mapping(flags)) + mm->stack_vm += npages; } static vm_fault_t special_mapping_fault(struct vm_fault *vmf);
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2.21.0