sys/prctl.h: add PR_*_TAGGED_ADDR_* from linux v5.4

per thread prctl commands to relax the syscall abi such that top bits
of user pointers are ignored in the kernel. this allows the use of
those bits by hwasan or by mte to color pointers and memory on aarch64:

  linux commit 63f0c60379650d82250f22e4cf4137ef3dc4f43d
  arm64: Introduce prctl() options to control the tagged user addresses ABI

diff --git a/include/sys/prctl.h b/include/sys/prctl.h
index 07f0d73dc78a5c0e38d1afa94eaf6698178165a1..d9c846e9c2eaec7103f71b9894d76a0b0345c1e2 100644 (file)
--- a/include/sys/prctl.h
+++ b/include/sys/prctl.h
@@ -154,6 +154,10 @@ struct prctl_mm_map {
 #define PR_PAC_APDBKEY (1UL << 3)
 #define PR_PAC_APGAKEY (1UL << 4)
 
+#define PR_SET_TAGGED_ADDR_CTRL 55
+#define PR_GET_TAGGED_ADDR_CTRL 56
+#define PR_TAGGED_ADDR_ENABLE (1UL << 0)
+
 int prctl (int, ...);
 
 #ifdef __cplusplus