On Thu, Feb 8, 2018 at 5:27 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, Feb 8, 2018 at 1:25 AM, Carlos O'Donell <carlos@redhat.com> wrote:
ils:
>>
>> The name NEED_SAVED_MASK_IN_CANCEL_JMP_BUF while true is slightly
>> misleading IMO. While it is true that you need the saved mask there, the
>> actual logical goal is to make the structure match in layout with the
>> non-cancel jmp_buf. I would rename this to NEED_SETJMP_LAYOUT or something
>
> Will do.
>
Here is the updated patch to revert
commit 2ec0e7eade0ea1258acd5c6f5e5e9bfaeb5041a8
Author: Carlos O'Donell <carlos@systemhalted.org>
Date: Wed Jan 24 20:35:22 2018 -0800
Revert Intel CET changes to __jmp_buf_tag (Bug 22743)
OK for trunk?
Thanks.
From 438aa89a52ea0ff382e3d57d05d4e879f2c71991 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 26 Jan 2018 05:19:15 -0800
Subject: [PATCH 1/2] Revert and update "Revert Intel CET changes to
__jmp_buf_tag (Bug 22743)"
This reverts commit 2ec0e7eade0ea1258acd5c6f5e5e9bfaeb5041a8, renames
sysdeps/unix/sysv/linux/x86/pthreaddef.h
to
sysdeps/unix/sysv/linux/x86/cancel_jmp_buf.h
and defines/checks NEED_SETJMP_JMP_BUF_LAYOUT instead of
NEED_SAVED_MASK_IN_CANCEL_JMP_BUF.
This is needed to save and restore shadow stack register in setjmp and
longjmp.
[BZ #22563]
* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
* sysdeps/i386/nptl/tls.h (tcbhead_t): Add feature_1.
* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Rename __glibc_unused1
to feature_1.
[BZ #22563]
* bits/types/__cancel_jmp_buf_tag.h: New file.
* sysdeps/nptl/cancel_jmp_buf.h: Likewise.
* sysdeps/unix/sysv/linux/x86/cancel_jmp_buf.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.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: Include <cancel_jmp_buf.h>.
[NEED_SETJMP_JMP_BUF_LAYOUT] (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.
* sysdeps/unix/sysv/linux/hppa/pthread.h: Likewise.
---
bits/types/__cancel_jmp_buf_tag.h | 28 +++++++++++++++++
nptl/Makefile | 3 +-
nptl/descr.h | 4 +++
sysdeps/i386/nptl/tcb-offsets.sym | 1 +
sysdeps/i386/nptl/tls.h | 4 +++
sysdeps/nptl/cancel_jmp_buf.h | 20 ++++++++++++
sysdeps/nptl/pthread.h | 7 ++---
sysdeps/unix/sysv/linux/hppa/pthread.h | 7 ++---
.../linux/x86/bits/types/__cancel_jmp_buf_tag.h | 31 +++++++++++++++++++
sysdeps/unix/sysv/linux/x86/cancel_jmp_buf.h | 20 ++++++++++++
sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h | 36 ++++++++++++++++++++++
sysdeps/x86_64/nptl/tcb-offsets.sym | 1 +
sysdeps/x86_64/nptl/tls.h | 5 ++-
13 files changed, 155 insertions(+), 12 deletions(-)
create mode 100644 bits/types/__cancel_jmp_buf_tag.h
create mode 100644 sysdeps/nptl/cancel_jmp_buf.h
create mode 100644 sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
create mode 100644 sysdeps/unix/sysv/linux/x86/cancel_jmp_buf.h
create mode 100644 sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h
new file mode 100644
@@ -0,0 +1,28 @@
+/* Define struct __cancel_jmp_buf_tag.
+ Copyright (C) 2017-2018 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
@@ -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)
@@ -28,6 +28,7 @@
#include <list_t.h>
#include <lowlevellock.h>
#include <pthreaddef.h>
+#include <cancel_jmp_buf.h>
#include <dl-sysdep.h>
#include "../nptl_db/thread_db.h"
#include <tls.h>
@@ -65,6 +66,9 @@ struct pthread_unwind_buf
{
__jmp_buf jmp_buf;
int mask_was_saved;
+#if NEED_SETJMP_JMP_BUF_LAYOUT
+ __sigset_t saved_mask;
+#endif
} cancel_jmp_buf[1];
union
@@ -15,3 +15,4 @@ POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
#ifndef __ASSUME_PRIVATE_FUTEX
PRIVATE_FUTEX offsetof (tcbhead_t, private_futex)
#endif
+FEATURE_1_OFFSET offsetof (tcbhead_t, feature_1)
@@ -50,6 +50,10 @@ typedef struct
void *__private_tm[4];
/* GCC split stack support. */
void *__private_ss;
+ /* Bit 0: IBT.
+ Bit 1: SHSTK.
+ */
+ unsigned int feature_1;
} tcbhead_t;
# define TLS_MULTIPLE_THREADS_IN_TCB 1
new file mode 100644
@@ -0,0 +1,20 @@
+/* Macros for cancel_jmp_buf. Generic version.
+ Copyright (C) 2018 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/>. */
+
+/* No need to use the same setjmp jmp_buf layout in cancel_jmp_buf. */
+#define NEED_SETJMP_JMP_BUF_LAYOUT 0
@@ -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__));
@@ -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. */
@@ -499,11 +500,7 @@ 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__));
new file mode 100644
@@ -0,0 +1,31 @@
+/* Define struct __cancel_jmp_buf_tag.
+ Copyright (C) 2017-2018 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
new file mode 100644
@@ -0,0 +1,20 @@
+/* Macros for cancel_jmp_buf. Linux/x86 version.
+ Copyright (C) 2018 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/>. */
+
+/* Need the same setjmp jmp_buf layout in cancel_jmp_buf. */
+#define NEED_SETJMP_JMP_BUF_LAYOUT 1
new file mode 100644
@@ -0,0 +1,36 @@
+/* Internal pthread header. Linux/x86 version.
+ Copyright (C) 2017-2018 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
@@ -15,6 +15,7 @@ VGETCPU_CACHE_OFFSET offsetof (tcbhead_t, vgetcpu_cache)
#ifndef __ASSUME_PRIVATE_FUTEX
PRIVATE_FUTEX offsetof (tcbhead_t, private_futex)
#endif
+FEATURE_1_OFFSET offsetof (tcbhead_t, feature_1)
-- Not strictly offsets, but these values are also used in the TCB.
TCB_CANCELSTATE_BITMASK CANCELSTATE_BITMASK
@@ -56,7 +56,10 @@ typedef struct
# else
int __glibc_reserved1;
# endif
- int __glibc_unused1;
+ /* Bit 0: IBT.
+ Bit 1: SHSTK.
+ */
+ unsigned int feature_1;
/* Reservation of some values for the TM ABI. */
void *__private_tm[4];
/* GCC split stack support. */
--
2.14.3