From 6a8628eca8c8b22ccfd1422f2eb27bb665cfd660 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Thu, 9 Dec 2021 09:49:32 +0100
Subject: [PATCH 3/9] nptl: Introduce THREAD_GETMEM_VOLATILE

This will be needed for rseq TCB access.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
---
 sysdeps/i386/nptl/tcb-access.h   | 2 ++
 sysdeps/nptl/tcb-access.h        | 2 ++
 sysdeps/x86_64/nptl/tcb-access.h | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/sysdeps/i386/nptl/tcb-access.h b/sysdeps/i386/nptl/tcb-access.h
index 6c6d561e..5ddd8322 100644
--- a/sysdeps/i386/nptl/tcb-access.h
+++ b/sysdeps/i386/nptl/tcb-access.h
@@ -41,6 +41,8 @@
        }								      \
      __value; })
 
+/* THREAD_GETMEM already forces a read.  */
+#define THREAD_GETMEM_VOLATILE(descr, member) THREAD_GETMEM (descr, member)
 
 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 #define THREAD_GETMEM_NC(descr, member, idx) \
diff --git a/sysdeps/nptl/tcb-access.h b/sysdeps/nptl/tcb-access.h
index b4137b8a..bbe20b72 100644
--- a/sysdeps/nptl/tcb-access.h
+++ b/sysdeps/nptl/tcb-access.h
@@ -22,6 +22,8 @@
 
 #define THREAD_GETMEM(descr, member) \
   descr->member
+#define THREAD_GETMEM_VOLATILE(descr, member) \
+  (*(volatile __typeof (descr->member) *)&descr->member)
 #define THREAD_GETMEM_NC(descr, member, idx) \
   descr->member[idx]
 #define THREAD_SETMEM(descr, member, value) \
diff --git a/sysdeps/x86_64/nptl/tcb-access.h b/sysdeps/x86_64/nptl/tcb-access.h
index 18848a72..e4d2d07a 100644
--- a/sysdeps/x86_64/nptl/tcb-access.h
+++ b/sysdeps/x86_64/nptl/tcb-access.h
@@ -39,6 +39,8 @@
        }								      \
      __value; })
 
+/* THREAD_GETMEM already forces a read.  */
+#define THREAD_GETMEM_VOLATILE(descr, member) THREAD_GETMEM (descr, member)
 
 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 # define THREAD_GETMEM_NC(descr, member, idx) \
-- 
2.23.0

