From 26450d04d38c8ed7ce5f2c89114b18c5508f13f1 Mon Sep 17 00:00:00 2001
From: Richard Earnshaw <rearnsha@arm.com>
Date: Mon, 21 Dec 2020 15:03:03 +0000
Subject: elf: Add a tunable to control use of tagged memory

Add a new glibc tunable: mem.tagging.  This is a decimal constant in
the range 0-255 but used as a bit-field.

Bit 0 enables use of tagged memory in the malloc family of functions.
Bit 1 enables precise faulting of tag failure on platforms where this
can be controlled.
Other bits are currently unused, but if set will cause memory tag
checking for the current process to be enabled in the kernel.
---
 elf/dl-tunables.list | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'elf')

diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list
index e1d8225128..4c44ead715 100644
--- a/elf/dl-tunables.list
+++ b/elf/dl-tunables.list
@@ -141,4 +141,13 @@ glibc {
       default: 512
     }
   }
+
+  mem {
+    tagging {
+      type: INT_32
+      minval: 0
+      maxval: 255
+      security_level: SXID_IGNORE
+    }
+  }
 }
-- 
cgit 1.4.1