The vdsocheck tool validates the object files and final .so library.
It can detect if the compiler created relocations which are incompatible
with the vDSO which need to be worked around.

Wire it up for the architecture.

The compat vDSO will be handled by the existing 32-bit ARM configuration.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/arm64/Kconfig              |  1 +
 arch/arm64/kernel/vdso/Makefile |  4 ++--
 lib/vdso/check/vdsocheck.rs     | 12 ++++++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b5a51b0ef944..1caaf4737f02 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -258,6 +258,7 @@ config ARM64
 	select TRACE_IRQFLAGS_NMI_SUPPORT
 	select HAVE_SOFTIRQ_ON_OWN_STACK
 	select USER_STACKTRACE_SUPPORT
+	select VDSO_CHECK
 	select VDSO_GETRANDOM
 	select VMAP_STACK
 	help
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 7dec05dd33b7..9fac0e54097d 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -61,7 +61,7 @@ targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Link rule for the .so file, .lds has to be first
-$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
+$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) $(vdsocheck) FORCE
 	$(call if_changed,vdsold_and_vdso_check)
 
 # Strip rule for the .so file
@@ -79,4 +79,4 @@ include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
 
 # Actual build commands
 quiet_cmd_vdsold_and_vdso_check = LD      $@
-      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
+      cmd_vdsold_and_vdso_check = $(cmd_ld_vdso); $(cmd_vdso_check)
diff --git a/lib/vdso/check/vdsocheck.rs b/lib/vdso/check/vdsocheck.rs
index fb88ef0be09d..e45a1fbc6829 100644
--- a/lib/vdso/check/vdsocheck.rs
+++ b/lib/vdso/check/vdsocheck.rs
@@ -57,6 +57,18 @@ fn allowed_relocations_for_machine(machine: u16) -> Option<AllowedRelocations<'s
             ..Default::default()
         }
         .into(),
+        bindings::EM_AARCH64 => AllowedRelocations {
+            in_object_file: &[
+                bindings::R_AARCH64_PREL64,
+                bindings::R_AARCH64_PREL32,
+                bindings::R_AARCH64_PREL16,
+                bindings::R_AARCH64_LD_PREL_LO19,
+                bindings::R_AARCH64_ADR_PREL_LO21,
+                bindings::R_AARCH64_CALL26,
+            ],
+            ..Default::default()
+        }
+        .into(),
         _ => None,
     }
 }

-- 
2.55.0