diff mbox series

[v7,15/23] aarch64: Add glibc.cpu.aarch64_gcs_policy tunable

Message ID 20250103154141.47731-16-yury.khrustalev@arm.com (mailing list archive)
State Superseded
Headers
Series aarch64: Add support for Guarded Control Stack extension |

Checks

Context Check Description
redhat-pt-bot/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Yury Khrustalev Jan. 3, 2025, 3:41 p.m. UTC 
  From: Szabolcs Nagy <szabolcs.nagy@arm.com>

policy sets how gcs tunable and gcs marking turns into gcs state:

0: state = tunable
1: state = marking ? tunable : (tunable && dlopen ? err : 0)
2: state = marking ? tunable : (tunable ? err : 0)

Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
---
 sysdeps/aarch64/dl-tunables.list               |  5 +++++
 sysdeps/unix/sysv/linux/aarch64/cpu-features.c |  9 +++++++--
 sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c  | 13 +++++++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/sysdeps/aarch64/dl-tunables.list b/sysdeps/aarch64/dl-tunables.list
index 4b28341b72..7fbd77a41b 100644
--- a/sysdeps/aarch64/dl-tunables.list
+++ b/sysdeps/aarch64/dl-tunables.list
@@ -26,5 +26,10 @@  glibc {
       minval: 0
       default: 0
     }
+    aarch64_gcs_policy {
+      type: UINT_64
+      minval: 0
+      default: 0
+    }
   }
 }
diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
index 97f61e05fe..1ee96213cd 100644
--- a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
+++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
@@ -182,6 +182,11 @@  init_cpu_features (struct cpu_features *cpu_features)
 #endif
 
   if (GLRO (dl_hwcap) & HWCAP_GCS)
-    /* GCS status may be updated later by binary compatibility checks.  */
-    GL (dl_aarch64_gcs) = TUNABLE_GET (glibc, cpu, aarch64_gcs, uint64_t, 0);
+    {
+      /* GCS status may be updated later by binary compatibility checks.  */
+      GL (dl_aarch64_gcs) = TUNABLE_GET (glibc, cpu, aarch64_gcs, uint64_t, 0);
+      /* Fixed GCS policy.  */
+      GLRO (dl_aarch64_gcs_policy) =
+	TUNABLE_GET (glibc, cpu, aarch64_gcs_policy, uint64_t, 0);
+    }
 }
diff --git a/sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c b/sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c
index 66287b4216..bcfc3fe030 100644
--- a/sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c
+++ b/sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c
@@ -54,6 +54,19 @@  PROCINFO_CLASS struct cpu_features _dl_aarch64_cpu_features
 # else
 ,
 # endif
+# if !defined PROCINFO_DECL && defined SHARED
+  ._dl_aarch64_gcs_policy
+# else
+PROCINFO_CLASS uint64_t _dl_aarch64_gcs_policy
+# endif
+# ifndef PROCINFO_DECL
+= 0
+# endif
+# if !defined SHARED || defined PROCINFO_DECL
+;
+# else
+,
+# endif
 #endif
 
 /* Number of HWCAP bits set.  */