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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
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