[01/23] x86: Add feature_1 to tcbhead_t [BZ #22563]

Message ID 20180508204021.31845-2-hjl.tools@gmail.com
State New
Headers show
Series
  • CET: Prepare for CET enabling
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Commit Message

H.J. Lu May 8, 2018, 8:39 p.m.
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/i386/nptl/tls.h (tcbhead_t): Add feature_1.
	* sysdeps/unix/sysv/linux/x86/pthreaddef.h: New file.
	* 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.
---
 nptl/pthread_create.c                    |  5 +++++
 sysdeps/i386/nptl/tcb-offsets.sym        |  1 +
 sysdeps/i386/nptl/tls.h                  |  4 ++++
 sysdeps/unix/sysv/linux/x86/pthreaddef.h | 24 ++++++++++++++++++++++++
 sysdeps/x86_64/nptl/tcb-offsets.sym      |  1 +
 sysdeps/x86_64/nptl/tls.h                |  5 ++++-
 6 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/unix/sysv/linux/x86/pthreaddef.h

Comments

Florian Weimer May 16, 2018, 2:28 p.m. | #1
On 05/08/2018 10:39 PM, H.J. Lu wrote:
> diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
> index 8ca0924692..c3a0edd253 100644
> --- a/sysdeps/i386/nptl/tls.h
> +++ b/sysdeps/i386/nptl/tls.h
> @@ -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;

It might be nicer to reuse __glibc_reserved1 for that (I think 
__ASSUME_PRIVATE_FUTEX is always defined these days), in case some 
extern tools hard-code the tcbhead_t layout.

Thanks,
Florian

Patch

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
+
   /* Verify the sysinfo bits were copied in allocate_stack if needed.  */
 #ifdef NEED_DL_SYSINFO
   CHECK_THREAD_SYSINFO (pd);
diff --git a/sysdeps/i386/nptl/tcb-offsets.sym b/sysdeps/i386/nptl/tcb-offsets.sym
index 695a810386..250f1a6e13 100644
--- a/sysdeps/i386/nptl/tcb-offsets.sym
+++ b/sysdeps/i386/nptl/tcb-offsets.sym
@@ -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)
diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
index 8ca0924692..c3a0edd253 100644
--- a/sysdeps/i386/nptl/tls.h
+++ b/sysdeps/i386/nptl/tls.h
@@ -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
diff --git a/sysdeps/unix/sysv/linux/x86/pthreaddef.h b/sysdeps/unix/sysv/linux/x86/pthreaddef.h
new file mode 100644
index 0000000000..539f6540d0
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/pthreaddef.h
@@ -0,0 +1,24 @@ 
+/* Pthread macros.  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/>.  */
+
+#include_next <pthreaddef.h>
+
+/* Wee need to copy feature_1 in pthread_create.  */
+#define THREAD_COPY_ADDITONAL_INFO(descr)				\
+  ((descr)->header.feature_1						\
+   = THREAD_GETMEM (THREAD_SELF, header.feature_1))
diff --git a/sysdeps/x86_64/nptl/tcb-offsets.sym b/sysdeps/x86_64/nptl/tcb-offsets.sym
index 8a25c482cb..03b6dba5c3 100644
--- a/sysdeps/x86_64/nptl/tcb-offsets.sym
+++ b/sysdeps/x86_64/nptl/tcb-offsets.sym
@@ -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
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 059f9675a0..87cc03ee5e 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -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.  */