From b6aad5a9958354e236f42877575e9f76f90348d1 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 6 Dec 2017 15:00:46 -0800
Subject: [PATCH] Linux/x86: Update cancel_jmp_buf to match __jmp_buf_tag [BZ
 #22563]

On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer
to support shadow stack in Intel Control-flow Enforcemen Technology.
Since the cancel_jmp_buf array is passed to setjmp and longjmp by
casting it to pointer to struct __jmp_buf_tag, it should be as large
as struct __jmp_buf_tag.

This patch adds bits/types/__cancel_jmp_buf_tag.h to define struct
__cancel_jmp_buf_tag so that Linux/x86 can add saved_mask to
cancel_jmp_buf.

Tested by build-many-glibcs.py.

	[BZ #22563]
	* bits/types/__cancel_jmp_buf_tag.h: New file.
	* sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
	* sysdeps/unix/sysv/linux/x86/pthreaddef.h: Likewise.
	* sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h: Likewise.
	* nptl/Makefile (headers): Add
	bits/types/__cancel_jmp_buf_tag.h.
	* nptl/descr.h [NEED_SAVED_MASK_IN_CANCEL_JMP_BUF]
	(pthread_unwind_buf): Add saved_mask to cancel_jmp_buf.
	* sysdeps/nptl/pthread.h: Include
	<bits/types/__cancel_jmp_buf_tag.h>.
	(__pthread_unwind_buf_t): Use struct __cancel_jmp_buf_tag with
	__cancel_jmp_buf.
---
 bits/types/__cancel_jmp_buf_tag.h                  | 28 +++++++++++++++++
 nptl/Makefile                                      |  3 +-
 nptl/descr.h                                       |  3 ++
 sysdeps/nptl/pthread.h                             |  7 ++---
 .../linux/x86/bits/types/__cancel_jmp_buf_tag.h    | 31 +++++++++++++++++++
 sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h        | 36 ++++++++++++++++++++++
 sysdeps/unix/sysv/linux/x86/pthreaddef.h           | 22 +++++++++++++
 7 files changed, 124 insertions(+), 6 deletions(-)
 create mode 100644 bits/types/__cancel_jmp_buf_tag.h
 create mode 100644 sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
 create mode 100644 sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h
 create mode 100644 sysdeps/unix/sysv/linux/x86/pthreaddef.h

diff --git a/bits/types/__cancel_jmp_buf_tag.h b/bits/types/__cancel_jmp_buf_tag.h
new file mode 100644
index 0000000000..c843f44239
--- /dev/null
+++ b/bits/types/__cancel_jmp_buf_tag.h
@@ -0,0 +1,28 @@
+/* Define struct __cancel_jmp_buf_tag.
+   Copyright (C) 2017 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/>.  */
+
+#ifndef ____cancel_jmp_buf_tag_defined
+#define ____cancel_jmp_buf_tag_defined 1
+
+struct __cancel_jmp_buf_tag
+  {
+    __jmp_buf __cancel_jmp_buf;
+    int __mask_was_saved;
+  };
+
+#endif
diff --git a/nptl/Makefile b/nptl/Makefile
index 11e6ecd88b..46e110773c 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -22,7 +22,8 @@ subdir	:= nptl
 
 include ../Makeconfig
 
-headers := pthread.h semaphore.h bits/semaphore.h
+headers := pthread.h semaphore.h bits/semaphore.h \
+	   bits/types/__cancel_jmp_buf_tag.h
 
 extra-libs := libpthread
 extra-libs-others := $(extra-libs)
diff --git a/nptl/descr.h b/nptl/descr.h
index c83b17b674..fdeb397eab 100644
--- a/nptl/descr.h
+++ b/nptl/descr.h
@@ -65,6 +65,9 @@ struct pthread_unwind_buf
   {
     __jmp_buf jmp_buf;
     int mask_was_saved;
+#ifdef NEED_SAVED_MASK_IN_CANCEL_JMP_BUF
+    __sigset_t saved_mask;
+#endif
   } cancel_jmp_buf[1];
 
   union
diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h
index 2b2b386ab3..787ac6e4cd 100644
--- a/sysdeps/nptl/pthread.h
+++ b/sysdeps/nptl/pthread.h
@@ -27,6 +27,7 @@
 #include <bits/setjmp.h>
 #include <bits/wordsize.h>
 #include <bits/types/struct_timespec.h>
+#include <bits/types/__cancel_jmp_buf_tag.h>
 
 
 /* Detach state.  */
@@ -523,11 +524,7 @@ extern void pthread_testcancel (void);
 
 typedef struct
 {
-  struct
-  {
-    __jmp_buf __cancel_jmp_buf;
-    int __mask_was_saved;
-  } __cancel_jmp_buf[1];
+  struct __cancel_jmp_buf_tag __cancel_jmp_buf[1];
   void *__pad[4];
 } __pthread_unwind_buf_t __attribute__ ((__aligned__));
 
diff --git a/sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h b/sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
new file mode 100644
index 0000000000..830a6ec90c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
@@ -0,0 +1,31 @@
+/* Define struct __cancel_jmp_buf_tag.
+   Copyright (C) 2017 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/>.  */
+
+#ifndef ____cancel_jmp_buf_tag_defined
+#define ____cancel_jmp_buf_tag_defined 1
+
+#include <bits/types/__sigset_t.h>
+
+struct __cancel_jmp_buf_tag
+  {
+    __jmp_buf __cancel_jmp_buf;
+    int __mask_was_saved;
+    __sigset_t __saved_mask;
+  };
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h b/sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h
new file mode 100644
index 0000000000..8c36ba3a5d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h
@@ -0,0 +1,36 @@
+/* Internal pthread header.  Linux/x86 version.
+   Copyright (C) 2017 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/>.  */
+
+#include_next <nptl/pthreadP.h>
+
+#ifndef _PTHREADP_H_X86
+#define _PTHREADP_H_X86 1
+
+extern struct pthread_unwind_buf ____pthread_unwind_buf_private;
+
+_Static_assert (sizeof (____pthread_unwind_buf_private.cancel_jmp_buf)
+		>= sizeof (struct __jmp_buf_tag),
+		"size of cancel_jmp_buf < sizeof __jmp_buf_tag");
+
+extern __pthread_unwind_buf_t ____pthread_unwind_buf;
+
+_Static_assert (sizeof (____pthread_unwind_buf.__cancel_jmp_buf)
+		>= sizeof (struct __jmp_buf_tag),
+		"size of __cancel_jmp_buf < sizeof __jmp_buf_tag");
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/x86/pthreaddef.h b/sysdeps/unix/sysv/linux/x86/pthreaddef.h
new file mode 100644
index 0000000000..89d19d60a1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/pthreaddef.h
@@ -0,0 +1,22 @@
+/* Pthread macros.  Linux/x86 version.
+   Copyright (C) 2017 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/>.  */
+
+#include_next <pthreaddef.h>
+
+/* Need saved_mask in cancel_jmp_buf.  */
+#define NEED_SAVED_MASK_IN_CANCEL_JMP_BUF 1
-- 
2.14.3
