| Message ID | 20210401221104.31584-19-yu-cheng.yu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v24,01/30] Documentation/x86: Add CET description | expand |
On Thu, Apr 01, 2021 at 03:10:52PM -0700, Yu-cheng Yu wrote: > Account shadow stack pages to stack memory. > > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> > Cc: Kees Cook <keescook@chromium.org> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > 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); > +} No, just define it as you have here in linux/mm.h. It will always be false for !CONFIG_ARCH_HAS_SHADOW_STACK as VM_SHADOW_STACK is 0 there. This maze of #ifdefs are unneeded.
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);
Account shadow stack pages to stack memory. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- 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(+)