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

[Carlos O'Donell <carlos at redhat dot com>]

On 07/13/2018 04:49 PM, H.J. Lu wrote:
> 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?

This version looks good. I have to go over your other patches and continue
reviewing. Thanks for the new versions.

Please commit.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> Thanks.
> 
> -- H.J.
> 
> 
> 0001-x86-Rename-__glibc_reserved1-to-feature_1-in-tcbhead.patch
> 
> 
> 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);

OK.

> +
>    /* 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