commit 93a6d0820430bfe3d09695a1376c07abf6d2214f

Author: Roland McGrath <roland@hack.frob.com>

Date:   Fri Jun 20 19:50:16 2014 -0700

    Clean up stack-coloring macros.

Conflicts:

	sysdeps/x86_64/nptl/Makefile

File change was applied to nptl/sysdeps/x86_64/Makefile instead.

diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c

index 2c126fd4ae447b25..0fba6ce3474e8b35 100644

--- a/nptl/allocatestack.c

+++ b/nptl/allocatestack.c

@@ -30,6 +30,7 @@

 #include <list.h>

 #include <lowlevellock.h>

 #include <kernel-features.h>

+#include <stack-aliasing.h>

 #ifndef NEED_SEPARATE_REGISTER_STACK

diff --git a/nptl/stack-aliasing.h b/nptl/stack-aliasing.h

new file mode 100644

index 0000000000000000..526b54e18f7e0a27

--- /dev/null

+++ b/nptl/stack-aliasing.h

@@ -0,0 +1,29 @@

+/* Define macros for stack address aliasing issues for NPTL.  Stub version.

+   Copyright (C) 2014 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; if not, see

+   <http://www.gnu.org/licenses/>.  */

+

+/* This is a number of bytes (less than a page) by which to "color" the

+   starting stack address of new threads.  This number is multiplied by the

+   number of threads created so far and then truncated modulo page size,

+   to get a roughly even distribution of values for different threads.  */

+#define COLORING_INCREMENT      0

+

+/* This is a number of bytes that is an alignment that should be avoided

+   when choosing the exact size of a new thread's stack.  If the size

+   chosen is aligned to this, an extra page will be added to render the

+   size off-aligned.  */

+#define MULTI_PAGE_ALIASING     0

diff --git a/nptl/sysdeps/x86_64/Makefile b/nptl/sysdeps/x86_64/Makefile

index d34dea709b363d2a..e2c47764e6e38c36 100644

--- a/nptl/sysdeps/x86_64/Makefile

+++ b/nptl/sysdeps/x86_64/Makefile

@@ -18,10 +18,3 @@

 ifeq ($(subdir),csu)

 gen-as-const-headers += tcb-offsets.sym

 endif

-

-ifeq ($(subdir),nptl)

-# P4s have problems with 4M aliasing.  We disturb the allocation of stacks

-# just enough so the subsequent allocations do not use stack address

-# (mod 4M) == 0.

-CFLAGS-pthread_create.c += -DMULTI_PAGE_ALIASING=65536

-endif

diff --git a/sysdeps/i386/i686/stack-aliasing.h b/sysdeps/i386/i686/stack-aliasing.h

new file mode 100644

index 0000000000000000..1e35ceb2061d60f9

--- /dev/null

+++ b/sysdeps/i386/i686/stack-aliasing.h

@@ -0,0 +1,28 @@

+/* Define macros for stack address aliasing issues for NPTL.  i686 version.

+   Copyright (C) 2014 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; if not, see

+   <http://www.gnu.org/licenses/>.  */

+

+/* It turns out that stack coloring is in general not good on P4s.  Some

+   applications will benefit.  We will probably have a configuration option

+   at some point.  To enable coloring, set this to 128.  */

+#define COLORING_INCREMENT      0

+

+/* What is useful is to avoid the 64k aliasing problem which reliably

+   happens if all stacks use sizes which are a multiple of 64k.  Tell

+   the stack allocator to disturb this by allocation one more page if

+   necessary.  */

+#define MULTI_PAGE_ALIASING     65536

diff --git a/sysdeps/x86_64/stack-aliasing.h b/sysdeps/x86_64/stack-aliasing.h

new file mode 100644

index 0000000000000000..2efdacb3b4c44c40

--- /dev/null

+++ b/sysdeps/x86_64/stack-aliasing.h

@@ -0,0 +1 @@

+#include <sysdeps/i386/i686/stack-aliasing.h>