On Mon, Jul 31, 2023 at 02:43:19PM +0100, Mark Brown wrote: > Use VM_HIGH_ARCH_5 for guarded control stack pages. > > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> > --- > Documentation/filesystems/proc.rst | 2 +- > fs/proc/task_mmu.c | 3 +++ > include/linux/mm.h | 12 +++++++++++- > 3 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst > index 6ccb57089a06..086a0408a4d7 100644 > --- a/Documentation/filesystems/proc.rst > +++ b/Documentation/filesystems/proc.rst > @@ -566,7 +566,7 @@ encoded manner. The codes are the following: > mt arm64 MTE allocation tags are enabled > um userfaultfd missing tracking > uw userfaultfd wr-protect tracking > - ss shadow stack page > + ss shadow/guarded control stack page I've missed this in Rick's patches, but it's not a page but area. > == ======================================= > > Note that there is no guarantee that every flag and associated mnemonic will > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index cfab855fe7e9..e8c50848bb16 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -711,6 +711,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) > #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ > #ifdef CONFIG_X86_USER_SHADOW_STACK > [ilog2(VM_SHADOW_STACK)] = "ss", > +#endif > +#ifdef CONFIG_ARM64_GCS > + [ilog2(VM_SHADOW_STACK)] = "ss", > #endif > }; > size_t i; > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 43fe625b85aa..3f939ae212e5 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -372,7 +372,17 @@ extern unsigned int kobjsize(const void *objp); > * having a PAGE_SIZE guard gap. > */ > # define VM_SHADOW_STACK VM_HIGH_ARCH_5 > -#else > +#endif > + > +#if defined(CONFIG_ARM64_GCS) > +/* > + * arm64's Guarded Control Stack implements similar functionality and > + * has similar constraints to shadow stacks. > + */ > +# define VM_SHADOW_STACK VM_HIGH_ARCH_5 > +#endif > + > +#ifndef VM_SHADOW_STACK > # define VM_SHADOW_STACK VM_NONE > #endif > > > -- > 2.30.2 > > -- Sincerely yours, Mike.
