From 2628500f5dff1dd99c49a09b418b3b1ea3a6b5d3 Mon Sep 17 00:00:00 2001
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Tue, 30 Aug 2022 10:33:15 -0300
Subject: [PATCH 143/143] m68k: Enforce 4-byte alignment on internal locks (BZ
#29537)
A new internal definition, __LIBC_LOCK_ALIGNMENT, is used to force
the 4-byte alignment only for m68k, other architecture keep the
natural alignment of the type used internally (and hppa does not
require 16-byte alignment for kernel-assisted CAS).
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit aeb4d2e9815d459e2640a31f5abb8ef803830107)
---
NEWS | 1 +
sysdeps/generic/libc-lock-arch.h | 25 +++++++++++++++++++
sysdeps/nptl/libc-lock.h | 8 +++++-
sysdeps/nptl/libc-lockP.h | 3 ++-
sysdeps/unix/sysv/linux/m68k/libc-lock-arch.h | 25 +++++++++++++++++++
5 files changed, 60 insertions(+), 2 deletions(-)
create mode 100644 sysdeps/generic/libc-lock-arch.h
create mode 100644 sysdeps/unix/sysv/linux/m68k/libc-lock-arch.h
diff --git a/NEWS b/NEWS
index eab882987bb9..1cc9a16bbfcb 100644
--- a/NEWS
+++ b/NEWS
@@ -25,6 +25,7 @@ The following bugs are resolved with this release:
[29485] Linux: Terminate subprocess on late failure in tst-pidfd
[29490] alpha: New __brk_call implementation is broken
[29528] elf: Call __libc_early_init for reused namespaces
+ [29537] libc: [2.34 regression]: Alignment issue on m68k when using
[29539] libc: LD_TRACE_LOADED_OBJECTS changed how vDSO library are
[29583] Use 64-bit interfaces in gconv_parseconfdir
diff --git a/sysdeps/generic/libc-lock-arch.h b/sysdeps/generic/libc-lock-arch.h
new file mode 100644
index 000000000000..4713b30a8aee
--- /dev/null
+++ b/sysdeps/generic/libc-lock-arch.h
@@ -0,0 +1,25 @@
+/* Private libc-internal arch-specific definitions. Generic version.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If
+ not, see <https://www.gnu.org/licenses/>. */
+
+#ifndef _LIBC_LOCK_ARCH_H
+#define _LIBC_LOCK_ARCH_H
+
+/* The default definition uses the natural alignment from the lock type. */
+#define __LIBC_LOCK_ALIGNMENT
+
+#endif
diff --git a/sysdeps/nptl/libc-lock.h b/sysdeps/nptl/libc-lock.h
index 5af476c48b7f..63b3f3d75ca1 100644
--- a/sysdeps/nptl/libc-lock.h
+++ b/sysdeps/nptl/libc-lock.h
@@ -22,6 +22,7 @@
#include <pthread.h>
#define __need_NULL
#include <stddef.h>
+#include <libc-lock-arch.h>
/* Mutex type. */
@@ -29,7 +30,12 @@
# if (!IS_IN (libc) && !IS_IN (libpthread)) || !defined _LIBC
typedef struct { pthread_mutex_t mutex; } __libc_lock_recursive_t;
# else
-typedef struct { int lock; int cnt; void *owner; } __libc_lock_recursive_t;
+typedef struct
+{
+ int lock __LIBC_LOCK_ALIGNMENT;
+ int cnt;
+ void *owner;
+} __libc_lock_recursive_t;
# endif
#else
typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
diff --git a/sysdeps/nptl/libc-lockP.h b/sysdeps/nptl/libc-lockP.h
index d3a6837fd212..425f514c5c47 100644
--- a/sysdeps/nptl/libc-lockP.h
+++ b/sysdeps/nptl/libc-lockP.h
@@ -32,9 +32,10 @@
ld.so might be used on old kernels with a different libc.so. */
#include <lowlevellock.h>
#include <tls.h>
+#include <libc-lock-arch.h>
/* Mutex type. */
-typedef int __libc_lock_t;
+typedef int __libc_lock_t __LIBC_LOCK_ALIGNMENT;
typedef struct { pthread_mutex_t mutex; } __rtld_lock_recursive_t;
typedef pthread_rwlock_t __libc_rwlock_t;
diff --git a/sysdeps/unix/sysv/linux/m68k/libc-lock-arch.h b/sysdeps/unix/sysv/linux/m68k/libc-lock-arch.h
new file mode 100644
index 000000000000..1844bbaf6f5d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/m68k/libc-lock-arch.h
@@ -0,0 +1,25 @@
+/* Private libc-internal arch-specific definitions. m68k version.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If
+ not, see <https://www.gnu.org/licenses/>. */
+
+#ifndef _LIBC_LOCK_ARCH_H
+#define _LIBC_LOCK_ARCH_H
+
+/* Linux enforces 4-bytes alignment on futex inputs. */
+#define __LIBC_LOCK_ALIGNMENT __attribute__ ((__aligned__ (4)))
+
+#endif
--
2.37.3
