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From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH v2 3/8] nptl: Introduce THREAD_GETMEM_VOLATILE
Date: Tue, 07 Dec 2021 14:00:39 +0100	[thread overview]
Message-ID: <42d7ef3c93f5c7959529c52c620e1e273cd69e83.1638880889.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1638880888.git.fweimer@redhat.com>

This will be needed for rseq TCB access.
---
v2: New patch.

 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 6c6d561e39..5ddd83224b 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 b4137b8ab8..bbe20b7225 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 18848a729d..e4d2d07a9b 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) \
-- 
2.33.1



  parent reply	other threads:[~2021-12-07 13:00 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-07 12:59 [PATCH v2 0/8] Extensible rseq integration Florian Weimer
2021-12-07 13:00 ` [PATCH 1/8] nptl: Add <thread_pointer.h> for defining __thread_pointer Florian Weimer
2021-12-08 11:05   ` Szabolcs Nagy
2021-12-08 17:55     ` Florian Weimer
2021-12-09 11:52       ` Szabolcs Nagy
2021-12-07 13:00 ` [PATCH v2 2/8] nptl: Introduce <tcb-access.h> for THREAD_* accessors Florian Weimer
2021-12-08 11:09   ` Szabolcs Nagy
2021-12-07 13:00 ` Florian Weimer [this message]
2021-12-08 11:23   ` [PATCH v2 3/8] nptl: Introduce THREAD_GETMEM_VOLATILE Szabolcs Nagy
2021-12-07 13:01 ` [PATCH 4/8] nptl: Add rseq registration Florian Weimer
2021-12-08 16:51   ` Szabolcs Nagy
2021-12-08 18:03   ` Siddhesh Poyarekar
2021-12-08 18:08     ` Florian Weimer
2021-12-08 23:27       ` Siddhesh Poyarekar
2021-12-09  7:42         ` Florian Weimer
2021-12-09  8:01           ` Siddhesh Poyarekar
2021-12-09  1:51   ` Noah Goldstein
2021-12-07 13:02 ` [PATCH v2 5/8] Linux: Use rseq to accelerate sched_getcpu Florian Weimer
2021-12-08 16:53   ` Szabolcs Nagy
2021-12-07 13:02 ` [PATCH v2 6/8] nptl: Add glibc.pthread.rseq tunable to control rseq registration Florian Weimer
2021-12-08 17:22   ` Szabolcs Nagy
2021-12-08 18:03   ` Siddhesh Poyarekar
2021-12-09  8:03     ` Siddhesh Poyarekar
2021-12-07 13:03 ` [PATCH 7/8] nptl: Add public rseq symbols and <sys/rseq.h> Florian Weimer
2021-12-08 17:34   ` Szabolcs Nagy
2021-12-09 12:26   ` Szabolcs Nagy
2021-12-09 12:34     ` Florian Weimer
2021-12-09 12:36     ` Szabolcs Nagy
2021-12-07 13:04 ` [PATCH v2 8/8] nptl: rseq failure after registration on main thread is fatal Florian Weimer
2021-12-08 17:36   ` Szabolcs Nagy
2022-02-01 15:21 ` [PATCH v2 0/8] Extensible rseq integration Rich Felker
2022-02-01 16:36   ` Florian Weimer
2022-02-03  0:37     ` Carlos O'Donell

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