| Message ID | 20241008-v5_user_cfi_series-v6-2-60d9fe073f37@rivosinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv control-flow integrity for usermode | expand |
On Tue, Oct 08, 2024 at 03:36:44PM -0700, Deepak Gupta wrote: > VM_SHADOW_STACK (alias to VM_HIGH_ARCH_5) is used to encode shadow stack > VMA on three architectures (x86 shadow stack, arm GCS and RISC-V shadow > stack). In case architecture doesn't implement shadow stack, it's VM_NONE > Introducing a helper `is_shadow_stack_vma` to determine shadow stack vma > or not. Not that it makes any difference but the arm64 eneded up defining VM_SHADOW_STACK to VM_HIGH_ARCH_6. > Signed-off-by: Deepak Gupta <debug@rivosinc.com> > --- > mm/gup.c | 2 +- > mm/vma.h | 10 +++++++--- > 2 files changed, 8 insertions(+), 4 deletions(-) There's another test of VM_SHADOW_STACK in mainline now, added by my change df7e1286b1dc3d6c ("mm: care about shadow stack guard gap when getting an unmapped area") - sorry, I should've remembered this change from your series and pulled it into mine. > @@ -387,7 +392,6 @@ static inline bool is_data_mapping(vm_flags_t flags) > return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; > } > > - > static inline void vma_iter_config(struct vma_iterator *vmi, > unsigned long index, unsigned long last) Unrelated whitespace change.
diff --git a/mm/gup.c b/mm/gup.c index a82890b46a36..8e6e14179f6c 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1282,7 +1282,7 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) !writable_file_mapping_allowed(vma, gup_flags)) return -EFAULT; - if (!(vm_flags & VM_WRITE) || (vm_flags & VM_SHADOW_STACK)) { + if (!(vm_flags & VM_WRITE) || is_shadow_stack_vma(vm_flags)) { if (!(gup_flags & FOLL_FORCE)) return -EFAULT; /* hugetlb does not support FOLL_FORCE|FOLL_WRITE. */ diff --git a/mm/vma.h b/mm/vma.h index 819f994cf727..0f238dc37231 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -357,7 +357,7 @@ static inline struct vm_area_struct *vma_prev_limit(struct vma_iterator *vmi, } /* - * These three helpers classifies VMAs for virtual memory accounting. + * These four helpers classifies VMAs for virtual memory accounting. */ /* @@ -368,6 +368,11 @@ static inline bool is_exec_mapping(vm_flags_t flags) return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; } +static inline bool is_shadow_stack_vma(vm_flags_t vm_flags) +{ + return !!(vm_flags & VM_SHADOW_STACK); +} + /* * Stack area (including shadow stacks) * @@ -376,7 +381,7 @@ static inline bool is_exec_mapping(vm_flags_t flags) */ static inline bool is_stack_mapping(vm_flags_t flags) { - return ((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK); + return ((flags & VM_STACK) == VM_STACK) || is_shadow_stack_vma(flags); } /* @@ -387,7 +392,6 @@ static inline bool is_data_mapping(vm_flags_t flags) return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; } - static inline void vma_iter_config(struct vma_iterator *vmi, unsigned long index, unsigned long last) {
VM_SHADOW_STACK (alias to VM_HIGH_ARCH_5) is used to encode shadow stack VMA on three architectures (x86 shadow stack, arm GCS and RISC-V shadow stack). In case architecture doesn't implement shadow stack, it's VM_NONE Introducing a helper `is_shadow_stack_vma` to determine shadow stack vma or not. Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- mm/gup.c | 2 +- mm/vma.h | 10 +++++++--- 2 files changed, 8 insertions(+), 4 deletions(-)