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V3: [PATCH 01/24] x86: Rename __glibc_reserved1 to feature_1 in tcbhead_t [BZ #22563]


On Fri, Jul 13, 2018 at 11:51 AM, Carlos O'Donell <carlos@redhat.com> wrote:
> On 07/13/2018 09:19 AM, H.J. Lu wrote:
>> On Wed, Jun 13, 2018 at 08:31:44AM -0700, H.J. Lu wrote:
>>> This will be used by CET run-time control.
>>>
>>>      [BZ #22563]
>>>      * nptl/pthread_create.c (__pthread_create_2_1): Use
>>>      THREAD_COPY_ADDITONAL_INFO to copy additonal info if defined.
>>>      * sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
>>>      * sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
>>>      Likewise.
>>>      * sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
>>>      to feature_1.
>>>      * sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
>>>      * sysdeps/unix/sysv/linux/x86/pthreaddef.h: New file.
>>
>> Here is the updated patch to add feature_1 to tcbhead_t and
>> introduce macros for CET enabling.  OK for master?
>
> Fix the typo-prone macro API and post a v3 please.
>
> Thank you.
>
>>
>> H.J.
>> ----
>> feature_1 has X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK bits for CET
>> run-time control.
>>
>> CET_ENABLED, IBT_ENABLED and SHSTK_ENABLED are defined to 1 or 0 to
>> indicate that if CET, IBT and SHSTK are enabled.
>
> OK.
>
>>
>>       [BZ #22563]
>>       * nptl/pthread_create.c (__pthread_create_2_1): Use
>>       THREAD_COPY_ADDITONAL_INFO to copy additonal info if defined.
>>       * sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
>>       * sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
>>       Likewise.
>>       * sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
>>       to feature_1.
>>       * sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
>>       * sysdeps/unix/sysv/linux/x86/pthreaddef.h: New file.
>>       * sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New.
>>       (X86_FEATURE_1_SHSTK): Likewise.
>>       (CET_ENABLED): Likewise.
>>       (IBT_ENABLED): Likewise.
>>       (SHSTK_ENABLED): Likewise.
>> ---
>>  nptl/pthread_create.c                    |  5 +++++
>>  sysdeps/i386/nptl/tcb-offsets.sym        |  1 +
>>  sysdeps/i386/nptl/tls.h                  |  5 ++++-
>>  sysdeps/unix/sysv/linux/x86/pthreaddef.h | 24 +++++++++++++++++++++
>>  sysdeps/x86/sysdep.h                     | 27 ++++++++++++++++++++++++
>>  sysdeps/x86_64/nptl/tcb-offsets.sym      |  1 +
>>  sysdeps/x86_64/nptl/tls.h                |  5 ++++-
>>  7 files changed, 66 insertions(+), 2 deletions(-)
>>  create mode 100644 sysdeps/unix/sysv/linux/x86/pthreaddef.h
>>
>> diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
>> index 92c945b12b..16998f4bbd 100644
>> --- a/nptl/pthread_create.c
>> +++ b/nptl/pthread_create.c
>> @@ -712,6 +712,11 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
>>    THREAD_COPY_POINTER_GUARD (pd);
>>  #endif
>>
>> +  /* Copy additonal info.  */
>> +#ifdef THREAD_COPY_ADDITONAL_INFO
>> +  THREAD_COPY_ADDITONAL_INFO (pd);
>> +#endif
>
> This is a typo-prone macro API.
>
> Please find a way to define this unconditionally.
>

Here is the V3 patch.  I added <tls-setup.h> to set up thread-local data.
OK for master?

Thanks.

-- 
H.J.
From 600fb331fed5aefc40bd3b95f753ab458b1b796b Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 7 Dec 2017 05:47:21 -0800
Subject: [PATCH 01/24] x86: Rename __glibc_reserved1 to feature_1 in tcbhead_t
 [BZ #22563]

feature_1 has X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK bits for CET
run-time control.

CET_ENABLED, IBT_ENABLED and SHSTK_ENABLED are defined to 1 or 0 to
indicate that if CET, IBT and SHSTK are enabled.

<tls-setup.h> is added to set up thread-local data.

	[BZ #22563]
	* nptl/pthread_create.c: Include <tls-setup.h>.
	(__pthread_create_2_1): Call tls_setup_tcbhead.
	* sysdeps/generic/tls-setup.h: New file.
	* sysdeps/x86/nptl/tls-setup.h: Likewise.
	* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
	* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
	Likewise.
	* sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
	to feature_1.
	* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
	* sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New.
	(X86_FEATURE_1_SHSTK): Likewise.
	(CET_ENABLED): Likewise.
	(IBT_ENABLED): Likewise.
	(SHSTK_ENABLED): Likewise.
---
 nptl/pthread_create.c               |  4 ++++
 sysdeps/generic/tls-setup.h         | 22 ++++++++++++++++++++++
 sysdeps/i386/nptl/tcb-offsets.sym   |  1 +
 sysdeps/i386/nptl/tls.h             |  5 ++++-
 sysdeps/x86/nptl/tls-setup.h        | 23 +++++++++++++++++++++++
 sysdeps/x86/sysdep.h                | 27 +++++++++++++++++++++++++++
 sysdeps/x86_64/nptl/tcb-offsets.sym |  1 +
 sysdeps/x86_64/nptl/tls.h           |  5 ++++-
 8 files changed, 86 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/generic/tls-setup.h
 create mode 100644 sysdeps/x86/nptl/tls-setup.h

diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 92c945b12b..5f5a007b7f 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -32,6 +32,7 @@
 #include <exit-thread.h>
 #include <default-sched.h>
 #include <futex-internal.h>
+#include <tls-setup.h>
 #include "libioP.h"
 
 #include <shlib-compat.h>
@@ -712,6 +713,9 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
   THREAD_COPY_POINTER_GUARD (pd);
 #endif
 
+  /* Setup tcbhead.  */
+  tls_setup_tcbhead (pd);
+
   /* Verify the sysinfo bits were copied in allocate_stack if needed.  */
 #ifdef NEED_DL_SYSINFO
   CHECK_THREAD_SYSINFO (pd);
diff --git a/sysdeps/generic/tls-setup.h b/sysdeps/generic/tls-setup.h
new file mode 100644
index 0000000000..36389b9bce
--- /dev/null
+++ b/sysdeps/generic/tls-setup.h
@@ -0,0 +1,22 @@
+/* Definitions to set up thread-local data.  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/>.  */
+
+static inline void __attribute__ ((always_inline))
+tls_setup_tcbhead (struct pthread *pd);
+{
+}
diff --git a/sysdeps/i386/nptl/tcb-offsets.sym b/sysdeps/i386/nptl/tcb-offsets.sym
index 7d7fe5e71c..fbac241c45 100644
--- a/sysdeps/i386/nptl/tcb-offsets.sym
+++ b/sysdeps/i386/nptl/tcb-offsets.sym
@@ -12,3 +12,4 @@ CLEANUP			offsetof (struct pthread, cleanup)
 CLEANUP_PREV		offsetof (struct _pthread_cleanup_buffer, __prev)
 MUTEX_FUTEX		offsetof (pthread_mutex_t, __data.__lock)
 POINTER_GUARD		offsetof (tcbhead_t, pointer_guard)
+FEATURE_1_OFFSET	offsetof (tcbhead_t, feature_1)
diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
index afb71ce431..21e23cd809 100644
--- a/sysdeps/i386/nptl/tls.h
+++ b/sysdeps/i386/nptl/tls.h
@@ -41,7 +41,10 @@ typedef struct
   uintptr_t stack_guard;
   uintptr_t pointer_guard;
   int gscope_flag;
-  int __glibc_reserved1;
+  /* Bit 0: X86_FEATURE_1_IBT.
+     Bit 1: X86_FEATURE_1_SHSTK.
+   */
+  unsigned int feature_1;
   /* Reservation of some values for the TM ABI.  */
   void *__private_tm[3];
   /* GCC split stack support.  */
diff --git a/sysdeps/x86/nptl/tls-setup.h b/sysdeps/x86/nptl/tls-setup.h
new file mode 100644
index 0000000000..ef5a4df78c
--- /dev/null
+++ b/sysdeps/x86/nptl/tls-setup.h
@@ -0,0 +1,23 @@
+/* Definitions to set up thread-local data.  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/>.  */
+
+static inline void __attribute__ ((always_inline))
+tls_setup_tcbhead (struct pthread *pd)
+{
+  pd->header.feature_1 = THREAD_GETMEM (THREAD_SELF, header.feature_1);
+}
diff --git a/sysdeps/x86/sysdep.h b/sysdeps/x86/sysdep.h
index afcb7cfd76..976566aa37 100644
--- a/sysdeps/x86/sysdep.h
+++ b/sysdeps/x86/sysdep.h
@@ -21,6 +21,33 @@
 
 #include <sysdeps/generic/sysdep.h>
 
+/* __CET__ is defined by GCC with Control-Flow Protection values:
+
+enum cf_protection_level
+{
+  CF_NONE = 0,
+  CF_BRANCH = 1 << 0,
+  CF_RETURN = 1 << 1,
+  CF_FULL = CF_BRANCH | CF_RETURN,
+  CF_SET = 1 << 2
+};
+*/
+
+/* Set if CF_BRANCH (IBT) is enabled.  */
+#define X86_FEATURE_1_IBT	(1U << 0)
+/* Set if CF_RETURN (SHSTK) is enabled.  */
+#define X86_FEATURE_1_SHSTK	(1U << 1)
+
+#ifdef __CET__
+# define CET_ENABLED	1
+# define IBT_ENABLED	(__CET__ & X86_FEATURE_1_IBT)
+# define SHSTK_ENABLED	(__CET__ & X86_FEATURE_1_SHSTK)
+#else
+# define CET_ENABLED	0
+# define IBT_ENABLED	0
+# define SHSTK_ENABLED	0
+#endif
+
 #ifdef	__ASSEMBLER__
 
 /* Syntactic details of assembler.  */
diff --git a/sysdeps/x86_64/nptl/tcb-offsets.sym b/sysdeps/x86_64/nptl/tcb-offsets.sym
index be63404a16..387621e88c 100644
--- a/sysdeps/x86_64/nptl/tcb-offsets.sym
+++ b/sysdeps/x86_64/nptl/tcb-offsets.sym
@@ -12,6 +12,7 @@ MUTEX_FUTEX		offsetof (pthread_mutex_t, __data.__lock)
 MULTIPLE_THREADS_OFFSET	offsetof (tcbhead_t, multiple_threads)
 POINTER_GUARD		offsetof (tcbhead_t, pointer_guard)
 VGETCPU_CACHE_OFFSET	offsetof (tcbhead_t, vgetcpu_cache)
+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
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 65c0051dcf..f042a0250a 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -51,7 +51,10 @@ typedef struct
   uintptr_t stack_guard;
   uintptr_t pointer_guard;
   unsigned long int vgetcpu_cache[2];
-  int __glibc_reserved1;
+  /* Bit 0: X86_FEATURE_1_IBT.
+     Bit 1: X86_FEATURE_1_SHSTK.
+   */
+  unsigned int feature_1;
   int __glibc_unused1;
   /* Reservation of some values for the TM ABI.  */
   void *__private_tm[4];
-- 
2.17.1


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