diff mbox series

[v13,14/40] mm: Define VM_SHADOW_STACK for arm64 when we support GCS

Message ID 20241001-arm64-gcs-v13-14-222b78d87eee@kernel.org (mailing list archive)
State Handled Elsewhere
Headers show
Series arm64/gcs: Provide support for GCS in userspace | expand

Commit Message

Mark Brown Oct. 1, 2024, 10:58 p.m. UTC 
Use VM_HIGH_ARCH_5 for guarded control stack pages.

Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 Documentation/filesystems/proc.rst |  2 +-
 include/linux/mm.h                 | 12 +++++++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index e834779d9611..6a882c57a7e7 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -579,7 +579,7 @@  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
     sl    sealed
     ==    =======================================
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 56654306a832..8852c39c7695 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -367,7 +367,17 @@  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_6
+#endif
+
+#ifndef VM_SHADOW_STACK
 # define VM_SHADOW_STACK	VM_NONE
 #endif