@@ -570,7 +570,7 @@ 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
== =======================================
Note that there is no guarantee that every flag and associated mnemonic will
@@ -699,6 +699,9 @@ 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;
@@ -352,7 +352,17 @@ extern unsigned int kobjsize(const void *objp);
* for more details on the guard size.
*/
# 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
Use VM_HIGH_ARCH_5 for guarded control stack pages. Signed-off-by: Mark Brown <broonie@kernel.org> --- Documentation/filesystems/proc.rst | 2 +- fs/proc/task_mmu.c | 3 +++ include/linux/mm.h | 12 +++++++++++- 3 files changed, 15 insertions(+), 2 deletions(-)