[v3,2/3] Consolidate Linux sigprocmask implementation (BZ #22391)

Message ID 1510768451-18453-2-git-send-email-adhemerval.zanella@linaro.org
State New
Headers show
Series
  • [v3,1/3] Rename nptl-signals.h to internal-signals.h
Related show

Commit Message

Adhemerval Zanella Nov. 15, 2017, 5:54 p.m.
Changes from previous version:

  - Cleanup __nptl prefix from the generic names.

---

This patch consolidates the sigprocmask Linux syscall implementation on
sysdeps/unix/sysv/linux/sigprocmask.c.  The changes are:

  1. For ia64, s390-64, sparc64, and x86_64 the default semantic for
     filter out SIGCANCEL and SIGSETXID is used.  Also the Linux pthread
     semantic is documented in the signal chapter.

  2. A new internal function to check for NPTL internal signals within a
     signal set is added (__has_internal_signal).  It is used to
     simplify the default sigprocmask.c implementation.

Checked on x86_64-linux-gnu.

	[BZ #22391]
	* manual/signal.texi: Add a note about internal pthread signals
	on Linux.
	* sysdeps/unix/sysv/linux/alpha/sigprocmask.c: Remove file.
	* sysdeps/unix/sysv/linux/ia64/sigprocmask.c: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sigprocmask.c: Likewise.
	* sysdeps/unix/sysv/linux/internal-signals.h
	(__has_internal_signal): New function.
	* sysdeps/unix/sysv/linux/sigprocmask.c (__sigprocmask):
	Use __has_internal_signal and __clear_internal_signals
	function.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

Signed-off-by: Zack Weinberg <zackw@panix.com>

Reported-by: Yury Norov <ynorov@caviumnetworks.com>
---
 ChangeLog                                          | 17 +++++++
 manual/signal.texi                                 | 37 ++++++++++++++
 sysdeps/unix/sysv/linux/alpha/sigprocmask.c        | 58 ----------------------
 sysdeps/unix/sysv/linux/ia64/sigprocmask.c         | 40 ---------------
 sysdeps/unix/sysv/linux/internal-signals.h         |  6 +++
 sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c | 38 --------------
 sysdeps/unix/sysv/linux/sigprocmask.c              | 23 +++------
 .../unix/sysv/linux/sparc/sparc64/sigprocmask.c    | 34 -------------
 sysdeps/unix/sysv/linux/x86_64/sigprocmask.c       | 39 ---------------
 9 files changed, 66 insertions(+), 226 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/alpha/sigprocmask.c
 delete mode 100644 sysdeps/unix/sysv/linux/ia64/sigprocmask.c
 delete mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c
 delete mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c
 delete mode 100644 sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

-- 
2.7.4

Comments

Rical Jasan Nov. 16, 2017, 1:16 a.m. | #1
Just one final nit.

On 11/15/2017 09:54 AM, Adhemerval Zanella wrote:
> diff --git a/manual/signal.texi b/manual/signal.texi

> index 9577ff0..4f0ef59 100644

> --- a/manual/signal.texi

> +++ b/manual/signal.texi

> @@ -235,6 +235,7 @@ defined.  Since the signal numbers are allocated consecutively,

>  * Job Control Signals::         Signals used to support job control.

>  * Operation Error Signals::     Used to report operational system errors.

>  * Miscellaneous Signals::       Miscellaneous Signals.

> +* Internally-Used Signals::     Signals used internally by the C library.

>  * Signal Messages::             Printing a message describing a signal.

>  @end menu

>  

> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.

>  The default action is to terminate the process.

>  @end deftypevr

>  

> +@deftypevr Macro int SIGRTMIN

> +@deftypevrx Macro int SIGRTMAX

> +@standards{POSIX.1, signal.h}

> +@cindex real-time signals


This @cindex should go above the @deftypevr to ensure the reader lands
above the heading.  Much of the time the difference probably won't be
noticeable, but it's annoying when you run into that off-chance of it
being on some weird boundary.  The Texinfo manual does mention keeping
index entries above "visible material" [1].

> +The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},

> +@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you

> +want.  In addition, these signals (and no others) are guaranteed to

> +support @dfn{real-time} signal semantics, which unfortunately this

> +manual does not yet document.

> +

> +Unlike all of the other signal number macros, @code{SIGRTMIN} and

> +@code{SIGRTMAX} are not compile-time constants, because some operating

> +systems make the number of real-time signals tunable on a

> +per-installation or even per-process basis.  However, POSIX guarantees

> +that there will be at least 8 signal numbers in this range.

> +

> +The default action for all signals in this range is to terminate the

> +process.

> +@end deftypevr

> +

>  @deftypevr Macro int SIGWINCH

>  @standards{BSD, signal.h}

>  Window size change.  This is generated on some systems (including GNU)

> @@ -817,6 +838,22 @@ to print some status information about the system and what the process

>  is doing.  Otherwise the default is to do nothing.

>  @end deftypevr

>  

> +@node Internally-Used Signals

> +@subsection Internally-Used Signals

> +@cindex internally used signals


This @cindex, however, must be underneath, as it won't be associated
with the correct section otherwise.

> +

> +On some operating systems, @theglibc{} needs to use a few signals from

> +the ``true'' real-time range internally, to implement thread

> +cancellation, cross-thread effective ID synchronization, POSIX timer

> +management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and

> +@code{SIGRTMAX} to exclude these signals, and it also takes steps to

> +prevent application code from altering their state: @code{sigprocmask}

> +cannot block them and @code{sigaction} cannot redefine their handlers,

> +for instance.  Therefore, most programs do not need to know or care

> +about these signals.  We mainly document their existence for the sake

> +of anyone who has ever wondered why there is a gap between the

> +highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.

> +

>  @node Signal Messages

>  @subsection Signal Messages

>  @cindex signal messages



Rical

[1]
https://www.gnu.org/software/texinfo/manual/texinfo/html_node/Indexing-Commands.html#Indexing-Commands
Adhemerval Zanella Nov. 16, 2017, 10:36 a.m. | #2
On 15/11/2017 23:16, Rical Jasan wrote:
> Just one final nit.

> 

> On 11/15/2017 09:54 AM, Adhemerval Zanella wrote:

>> diff --git a/manual/signal.texi b/manual/signal.texi

>> index 9577ff0..4f0ef59 100644

>> --- a/manual/signal.texi

>> +++ b/manual/signal.texi

>> @@ -235,6 +235,7 @@ defined.  Since the signal numbers are allocated consecutively,

>>  * Job Control Signals::         Signals used to support job control.

>>  * Operation Error Signals::     Used to report operational system errors.

>>  * Miscellaneous Signals::       Miscellaneous Signals.

>> +* Internally-Used Signals::     Signals used internally by the C library.

>>  * Signal Messages::             Printing a message describing a signal.

>>  @end menu

>>  

>> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.

>>  The default action is to terminate the process.

>>  @end deftypevr

>>  

>> +@deftypevr Macro int SIGRTMIN

>> +@deftypevrx Macro int SIGRTMAX

>> +@standards{POSIX.1, signal.h}

>> +@cindex real-time signals

> 

> This @cindex should go above the @deftypevr to ensure the reader lands

> above the heading.  Much of the time the difference probably won't be

> noticeable, but it's annoying when you run into that off-chance of it

> being on some weird boundary.  The Texinfo manual does mention keeping

> index entries above "visible material" [1].


Ack, I have changed it locally.

> 

>> +The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},

>> +@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you

>> +want.  In addition, these signals (and no others) are guaranteed to

>> +support @dfn{real-time} signal semantics, which unfortunately this

>> +manual does not yet document.

>> +

>> +Unlike all of the other signal number macros, @code{SIGRTMIN} and

>> +@code{SIGRTMAX} are not compile-time constants, because some operating

>> +systems make the number of real-time signals tunable on a

>> +per-installation or even per-process basis.  However, POSIX guarantees

>> +that there will be at least 8 signal numbers in this range.

>> +

>> +The default action for all signals in this range is to terminate the

>> +process.

>> +@end deftypevr

>> +

>>  @deftypevr Macro int SIGWINCH

>>  @standards{BSD, signal.h}

>>  Window size change.  This is generated on some systems (including GNU)

>> @@ -817,6 +838,22 @@ to print some status information about the system and what the process

>>  is doing.  Otherwise the default is to do nothing.

>>  @end deftypevr

>>  

>> +@node Internally-Used Signals

>> +@subsection Internally-Used Signals

>> +@cindex internally used signals

> 

> This @cindex, however, must be underneath, as it won't be associated

> with the correct section otherwise.


Right, so I presume it is on right position, correct?

> 

>> +

>> +On some operating systems, @theglibc{} needs to use a few signals from

>> +the ``true'' real-time range internally, to implement thread

>> +cancellation, cross-thread effective ID synchronization, POSIX timer

>> +management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and

>> +@code{SIGRTMAX} to exclude these signals, and it also takes steps to

>> +prevent application code from altering their state: @code{sigprocmask}

>> +cannot block them and @code{sigaction} cannot redefine their handlers,

>> +for instance.  Therefore, most programs do not need to know or care

>> +about these signals.  We mainly document their existence for the sake

>> +of anyone who has ever wondered why there is a gap between the

>> +highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.

>> +

>>  @node Signal Messages

>>  @subsection Signal Messages

>>  @cindex signal messages

> 

> 

> Rical

> 

> [1]

> https://www.gnu.org/software/texinfo/manual/texinfo/html_node/Indexing-Commands.html#Indexing-Commands

>
Rical Jasan Nov. 16, 2017, 12:17 p.m. | #3
On 11/16/2017 02:36 AM, Adhemerval Zanella wrote:
> On 15/11/2017 23:16, Rical Jasan wrote:

>> Just one final nit.

>>

>> On 11/15/2017 09:54 AM, Adhemerval Zanella wrote:

>>> diff --git a/manual/signal.texi b/manual/signal.texi

>>> index 9577ff0..4f0ef59 100644

>>> --- a/manual/signal.texi

>>> +++ b/manual/signal.texi

...
>>> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.

>>>  The default action is to terminate the process.

>>>  @end deftypevr

>>>  

>>> +@deftypevr Macro int SIGRTMIN

>>> +@deftypevrx Macro int SIGRTMAX

>>> +@standards{POSIX.1, signal.h}

>>> +@cindex real-time signals

>>

>> This @cindex should go above the @deftypevr to ensure the reader lands

>> above the heading.  Much of the time the difference probably won't be

>> noticeable, but it's annoying when you run into that off-chance of it

>> being on some weird boundary.  The Texinfo manual does mention keeping

>> index entries above "visible material" [1].

> 

> Ack, I have changed it locally.

...
>>>  

>>> +@node Internally-Used Signals

>>> +@subsection Internally-Used Signals

>>> +@cindex internally used signals

>>

>> This @cindex, however, must be underneath, as it won't be associated

>> with the correct section otherwise.

> 

> Right, so I presume it is on right position, correct?

Correct.  I just felt a need to point out that this was an exception to
the rule above since I was being nit-picky.  :)

Rical
Adhemerval Zanella Dec. 12, 2017, 5:03 p.m. | #4
Ping (with Rical suggested changes).

On 15/11/2017 15:54, Adhemerval Zanella wrote:
> Changes from previous version:

> 

>   - Cleanup __nptl prefix from the generic names.

> 

> ---

> 

> This patch consolidates the sigprocmask Linux syscall implementation on

> sysdeps/unix/sysv/linux/sigprocmask.c.  The changes are:

> 

>   1. For ia64, s390-64, sparc64, and x86_64 the default semantic for

>      filter out SIGCANCEL and SIGSETXID is used.  Also the Linux pthread

>      semantic is documented in the signal chapter.

> 

>   2. A new internal function to check for NPTL internal signals within a

>      signal set is added (__has_internal_signal).  It is used to

>      simplify the default sigprocmask.c implementation.

> 

> Checked on x86_64-linux-gnu.

> 

> 	[BZ #22391]

> 	* manual/signal.texi: Add a note about internal pthread signals

> 	on Linux.

> 	* sysdeps/unix/sysv/linux/alpha/sigprocmask.c: Remove file.

> 	* sysdeps/unix/sysv/linux/ia64/sigprocmask.c: Likewise.

> 	* sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c: Likewise.

> 	* sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c: Likewise.

> 	* sysdeps/unix/sysv/linux/x86_64/sigprocmask.c: Likewise.

> 	* sysdeps/unix/sysv/linux/internal-signals.h

> 	(__has_internal_signal): New function.

> 	* sysdeps/unix/sysv/linux/sigprocmask.c (__sigprocmask):

> 	Use __has_internal_signal and __clear_internal_signals

> 	function.

> 

> Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> Signed-off-by: Zack Weinberg <zackw@panix.com>

> Reported-by: Yury Norov <ynorov@caviumnetworks.com>

> ---

>  ChangeLog                                          | 17 +++++++

>  manual/signal.texi                                 | 37 ++++++++++++++

>  sysdeps/unix/sysv/linux/alpha/sigprocmask.c        | 58 ----------------------

>  sysdeps/unix/sysv/linux/ia64/sigprocmask.c         | 40 ---------------

>  sysdeps/unix/sysv/linux/internal-signals.h         |  6 +++

>  sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c | 38 --------------

>  sysdeps/unix/sysv/linux/sigprocmask.c              | 23 +++------

>  .../unix/sysv/linux/sparc/sparc64/sigprocmask.c    | 34 -------------

>  sysdeps/unix/sysv/linux/x86_64/sigprocmask.c       | 39 ---------------

>  9 files changed, 66 insertions(+), 226 deletions(-)

>  delete mode 100644 sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>  delete mode 100644 sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>  delete mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>  delete mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>  delete mode 100644 sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

> 

> diff --git a/manual/signal.texi b/manual/signal.texi

> index 9577ff0..4f0ef59 100644

> --- a/manual/signal.texi

> +++ b/manual/signal.texi

> @@ -235,6 +235,7 @@ defined.  Since the signal numbers are allocated consecutively,

>  * Job Control Signals::         Signals used to support job control.

>  * Operation Error Signals::     Used to report operational system errors.

>  * Miscellaneous Signals::       Miscellaneous Signals.

> +* Internally-Used Signals::     Signals used internally by the C library.

>  * Signal Messages::             Printing a message describing a signal.

>  @end menu

>  

> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.

>  The default action is to terminate the process.

>  @end deftypevr

>  

> +@deftypevr Macro int SIGRTMIN

> +@deftypevrx Macro int SIGRTMAX

> +@standards{POSIX.1, signal.h}

> +@cindex real-time signals

> +The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},

> +@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you

> +want.  In addition, these signals (and no others) are guaranteed to

> +support @dfn{real-time} signal semantics, which unfortunately this

> +manual does not yet document.

> +

> +Unlike all of the other signal number macros, @code{SIGRTMIN} and

> +@code{SIGRTMAX} are not compile-time constants, because some operating

> +systems make the number of real-time signals tunable on a

> +per-installation or even per-process basis.  However, POSIX guarantees

> +that there will be at least 8 signal numbers in this range.

> +

> +The default action for all signals in this range is to terminate the

> +process.

> +@end deftypevr

> +

>  @deftypevr Macro int SIGWINCH

>  @standards{BSD, signal.h}

>  Window size change.  This is generated on some systems (including GNU)

> @@ -817,6 +838,22 @@ to print some status information about the system and what the process

>  is doing.  Otherwise the default is to do nothing.

>  @end deftypevr

>  

> +@node Internally-Used Signals

> +@subsection Internally-Used Signals

> +@cindex internally used signals

> +

> +On some operating systems, @theglibc{} needs to use a few signals from

> +the ``true'' real-time range internally, to implement thread

> +cancellation, cross-thread effective ID synchronization, POSIX timer

> +management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and

> +@code{SIGRTMAX} to exclude these signals, and it also takes steps to

> +prevent application code from altering their state: @code{sigprocmask}

> +cannot block them and @code{sigaction} cannot redefine their handlers,

> +for instance.  Therefore, most programs do not need to know or care

> +about these signals.  We mainly document their existence for the sake

> +of anyone who has ever wondered why there is a gap between the

> +highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.

> +

>  @node Signal Messages

>  @subsection Signal Messages

>  @cindex signal messages

> diff --git a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c b/sysdeps/unix/sysv/linux/alpha/sigprocmask.c

> deleted file mode 100644

> index ebec70c..0000000

> --- a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c

> +++ /dev/null

> @@ -1,58 +0,0 @@

> -/* Copyright (C) 1993-2017 Free Software Foundation, Inc.

> -   This file is part of the GNU C Library.

> -   Contributed by David Mosberger (davidm@azstarnet.com).

> -

> -   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 <errno.h>

> -#include <sysdep.h>

> -#include <signal.h>

> -

> -/* When there is kernel support for more than 64 signals, we'll have to

> -   switch to a new system call convention here.  */

> -

> -int

> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

> -{

> -  unsigned long int setval;

> -  long result;

> -

> -  if (set)

> -    setval = set->__val[0];

> -  else

> -    {

> -      setval = 0;

> -      how = SIG_BLOCK;	/* ensure blocked mask doesn't get changed */

> -    }

> -

> -  result = INLINE_SYSCALL (osf_sigprocmask, 2, how, setval);

> -  if (result == -1)

> -    /* If there are ever more than 63 signals, we need to recode this

> -       in assembler since we wouldn't be able to distinguish a mask of

> -       all 1s from -1, but for now, we're doing just fine... */

> -    return result;

> -

> -  if (oset)

> -    {

> -      oset->__val[0] = result;

> -      result = _SIGSET_NWORDS;

> -      while (--result > 0)

> -	oset->__val[result] = 0;

> -    }

> -  return 0;

> -}

> -

> -libc_hidden_def (__sigprocmask)

> -weak_alias (__sigprocmask, sigprocmask);

> diff --git a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c b/sysdeps/unix/sysv/linux/ia64/sigprocmask.c

> deleted file mode 100644

> index 920c5fd..0000000

> --- a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c

> +++ /dev/null

> @@ -1,40 +0,0 @@

> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

> -   This file is part of the GNU C Library.

> -   Linux/IA64 specific sigprocmask

> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.

> -

> -   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/>.  */

> -

> -/* Linux/ia64 only has rt signals, thus we do not even want to try falling

> -   back to the old style signals as the default Linux handler does. */

> -

> -#include <errno.h>

> -#include <signal.h>

> -#include <unistd.h>

> -

> -#include <sysdep.h>

> -#include <sys/syscall.h>

> -

> -/* Get and/or change the set of blocked signals.  */

> -int

> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

> -{

> -

> -  /* XXX The size argument hopefully will have to be changed to the

> -     real size of the user-level sigset_t.  */

> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

> -}

> -libc_hidden_def (__sigprocmask)

> -weak_alias (__sigprocmask, sigprocmask)

> diff --git a/sysdeps/unix/sysv/linux/internal-signals.h b/sysdeps/unix/sysv/linux/internal-signals.h

> index e96a718..bb8234d 100644

> --- a/sysdeps/unix/sysv/linux/internal-signals.h

> +++ b/sysdeps/unix/sysv/linux/internal-signals.h

> @@ -36,6 +36,12 @@

>  #define SIGSETXID       (__SIGRTMIN + 1)

>  

>  

> +static inline bool

> +__has_internal_signal (const sigset_t *set)

> +{

> +  return __sigismember (set, SIGCANCEL) || __sigismember (set, SIGSETXID);

> +}

> +

>  /* Return is sig is used internally.  */

>  static inline int

>  __is_internal_signal (int sig)

> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c b/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

> deleted file mode 100644

> index a8010e7..0000000

> --- a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

> +++ /dev/null

> @@ -1,38 +0,0 @@

> -/* Copyright (C) 2001-2017 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/>.  */

> -

> -/* 64 bit Linux for S/390 only has rt signals, thus we do not even want to try

> -   falling back to the old style signals as the default Linux handler does. */

> -

> -#include <errno.h>

> -#include <signal.h>

> -#include <unistd.h>

> -

> -#include <sysdep.h>

> -#include <sys/syscall.h>

> -

> -/* Get and/or change the set of blocked signals.  */

> -int

> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

> -{

> -

> -  /* XXX The size argument hopefully will have to be changed to the

> -     real size of the user-level sigset_t.  */

> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

> -}

> -libc_hidden_def (__sigprocmask)

> -weak_alias (__sigprocmask, sigprocmask)

> diff --git a/sysdeps/unix/sysv/linux/sigprocmask.c b/sysdeps/unix/sysv/linux/sigprocmask.c

> index e776563..e574b5d 100644

> --- a/sysdeps/unix/sysv/linux/sigprocmask.c

> +++ b/sysdeps/unix/sysv/linux/sigprocmask.c

> @@ -1,4 +1,5 @@

> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

> +/* Get and/or change the set of blocked signals.  Linux version.

> +   Copyright (C) 1997-2017 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

> @@ -17,34 +18,22 @@

>  

>  #include <errno.h>

>  #include <signal.h>

> -#include <string.h>  /* Needed for string function builtin redirection.  */

> -#include <unistd.h>

> +#include <internal-signals.h>

>  

> -#include <sysdep.h>

> -#include <sys/syscall.h>

>  

> -#include <nptl/pthreadP.h>              /* SIGCANCEL, SIGSETXID */

> -

> -

> -/* Get and/or change the set of blocked signals.  */

>  int

>  __sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>  {

>    sigset_t local_newmask;

>  

> -  /* The only thing we have to make sure here is that SIGCANCEL and

> -     SIGSETXID are not blocked.  */

> -  if (set != NULL

> -      && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)

> -	  || __builtin_expect (__sigismember (set, SIGSETXID), 0)))

> +  if (set != NULL && __glibc_unlikely (__has_internal_signal (set)))

>      {

>        local_newmask = *set;

> -      __sigdelset (&local_newmask, SIGCANCEL);

> -      __sigdelset (&local_newmask, SIGSETXID);

> +      __clear_internal_signals (&local_newmask);

>        set = &local_newmask;

>      }

>  

> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

> +  return INLINE_SYSCALL_CALL (rt_sigprocmask, how, set, oset, _NSIG / 8);

>  }

>  libc_hidden_def (__sigprocmask)

>  weak_alias (__sigprocmask, sigprocmask)

> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c b/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

> deleted file mode 100644

> index ef7d7fe..0000000

> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

> +++ /dev/null

> @@ -1,34 +0,0 @@

> -/* Copyright (C) 1997-2017 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 <errno.h>

> -#include <signal.h>

> -#include <unistd.h>

> -

> -#include <sysdep.h>

> -#include <sys/syscall.h>

> -

> -/* Get and/or change the set of blocked signals.  */

> -int

> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

> -{

> -  /* XXX The size argument hopefully will have to be changed to the

> -     real size of the user-level sigset_t.  */

> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

> -}

> -libc_hidden_def (__sigprocmask)

> -weak_alias (__sigprocmask, sigprocmask)

> diff --git a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c b/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

> deleted file mode 100644

> index 1610ddf..0000000

> --- a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

> +++ /dev/null

> @@ -1,39 +0,0 @@

> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

> -   This file is part of the GNU C Library.

> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.

> -

> -   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/>.  */

> -

> -/* Linux/x86_64 only has rt signals, thus we do not even want to try falling

> -   back to the old style signals as the default Linux handler does. */

> -

> -#include <errno.h>

> -#include <signal.h>

> -#include <unistd.h>

> -

> -#include <sysdep.h>

> -#include <sys/syscall.h>

> -

> -/* Get and/or change the set of blocked signals.  */

> -int

> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

> -{

> -

> -  /* XXX The size argument hopefully will have to be changed to the

> -     real size of the user-level sigset_t.  */

> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

> -}

> -libc_hidden_def (__sigprocmask)

> -weak_alias (__sigprocmask, sigprocmask)

>
Adhemerval Zanella Jan. 1, 2018, 9:56 p.m. | #5
Ping.

On 12/12/2017 15:03, Adhemerval Zanella wrote:
> Ping (with Rical suggested changes).

> 

> On 15/11/2017 15:54, Adhemerval Zanella wrote:

>> Changes from previous version:

>>

>>   - Cleanup __nptl prefix from the generic names.

>>

>> ---

>>

>> This patch consolidates the sigprocmask Linux syscall implementation on

>> sysdeps/unix/sysv/linux/sigprocmask.c.  The changes are:

>>

>>   1. For ia64, s390-64, sparc64, and x86_64 the default semantic for

>>      filter out SIGCANCEL and SIGSETXID is used.  Also the Linux pthread

>>      semantic is documented in the signal chapter.

>>

>>   2. A new internal function to check for NPTL internal signals within a

>>      signal set is added (__has_internal_signal).  It is used to

>>      simplify the default sigprocmask.c implementation.

>>

>> Checked on x86_64-linux-gnu.

>>

>> 	[BZ #22391]

>> 	* manual/signal.texi: Add a note about internal pthread signals

>> 	on Linux.

>> 	* sysdeps/unix/sysv/linux/alpha/sigprocmask.c: Remove file.

>> 	* sysdeps/unix/sysv/linux/ia64/sigprocmask.c: Likewise.

>> 	* sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c: Likewise.

>> 	* sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c: Likewise.

>> 	* sysdeps/unix/sysv/linux/x86_64/sigprocmask.c: Likewise.

>> 	* sysdeps/unix/sysv/linux/internal-signals.h

>> 	(__has_internal_signal): New function.

>> 	* sysdeps/unix/sysv/linux/sigprocmask.c (__sigprocmask):

>> 	Use __has_internal_signal and __clear_internal_signals

>> 	function.

>>

>> Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

>> Signed-off-by: Zack Weinberg <zackw@panix.com>

>> Reported-by: Yury Norov <ynorov@caviumnetworks.com>

>> ---

>>  ChangeLog                                          | 17 +++++++

>>  manual/signal.texi                                 | 37 ++++++++++++++

>>  sysdeps/unix/sysv/linux/alpha/sigprocmask.c        | 58 ----------------------

>>  sysdeps/unix/sysv/linux/ia64/sigprocmask.c         | 40 ---------------

>>  sysdeps/unix/sysv/linux/internal-signals.h         |  6 +++

>>  sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c | 38 --------------

>>  sysdeps/unix/sysv/linux/sigprocmask.c              | 23 +++------

>>  .../unix/sysv/linux/sparc/sparc64/sigprocmask.c    | 34 -------------

>>  sysdeps/unix/sysv/linux/x86_64/sigprocmask.c       | 39 ---------------

>>  9 files changed, 66 insertions(+), 226 deletions(-)

>>  delete mode 100644 sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>>  delete mode 100644 sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>>  delete mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>>  delete mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>>  delete mode 100644 sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

>>

>> diff --git a/manual/signal.texi b/manual/signal.texi

>> index 9577ff0..4f0ef59 100644

>> --- a/manual/signal.texi

>> +++ b/manual/signal.texi

>> @@ -235,6 +235,7 @@ defined.  Since the signal numbers are allocated consecutively,

>>  * Job Control Signals::         Signals used to support job control.

>>  * Operation Error Signals::     Used to report operational system errors.

>>  * Miscellaneous Signals::       Miscellaneous Signals.

>> +* Internally-Used Signals::     Signals used internally by the C library.

>>  * Signal Messages::             Printing a message describing a signal.

>>  @end menu

>>  

>> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.

>>  The default action is to terminate the process.

>>  @end deftypevr

>>  

>> +@deftypevr Macro int SIGRTMIN

>> +@deftypevrx Macro int SIGRTMAX

>> +@standards{POSIX.1, signal.h}

>> +@cindex real-time signals

>> +The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},

>> +@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you

>> +want.  In addition, these signals (and no others) are guaranteed to

>> +support @dfn{real-time} signal semantics, which unfortunately this

>> +manual does not yet document.

>> +

>> +Unlike all of the other signal number macros, @code{SIGRTMIN} and

>> +@code{SIGRTMAX} are not compile-time constants, because some operating

>> +systems make the number of real-time signals tunable on a

>> +per-installation or even per-process basis.  However, POSIX guarantees

>> +that there will be at least 8 signal numbers in this range.

>> +

>> +The default action for all signals in this range is to terminate the

>> +process.

>> +@end deftypevr

>> +

>>  @deftypevr Macro int SIGWINCH

>>  @standards{BSD, signal.h}

>>  Window size change.  This is generated on some systems (including GNU)

>> @@ -817,6 +838,22 @@ to print some status information about the system and what the process

>>  is doing.  Otherwise the default is to do nothing.

>>  @end deftypevr

>>  

>> +@node Internally-Used Signals

>> +@subsection Internally-Used Signals

>> +@cindex internally used signals

>> +

>> +On some operating systems, @theglibc{} needs to use a few signals from

>> +the ``true'' real-time range internally, to implement thread

>> +cancellation, cross-thread effective ID synchronization, POSIX timer

>> +management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and

>> +@code{SIGRTMAX} to exclude these signals, and it also takes steps to

>> +prevent application code from altering their state: @code{sigprocmask}

>> +cannot block them and @code{sigaction} cannot redefine their handlers,

>> +for instance.  Therefore, most programs do not need to know or care

>> +about these signals.  We mainly document their existence for the sake

>> +of anyone who has ever wondered why there is a gap between the

>> +highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.

>> +

>>  @node Signal Messages

>>  @subsection Signal Messages

>>  @cindex signal messages

>> diff --git a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c b/sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>> deleted file mode 100644

>> index ebec70c..0000000

>> --- a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>> +++ /dev/null

>> @@ -1,58 +0,0 @@

>> -/* Copyright (C) 1993-2017 Free Software Foundation, Inc.

>> -   This file is part of the GNU C Library.

>> -   Contributed by David Mosberger (davidm@azstarnet.com).

>> -

>> -   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 <errno.h>

>> -#include <sysdep.h>

>> -#include <signal.h>

>> -

>> -/* When there is kernel support for more than 64 signals, we'll have to

>> -   switch to a new system call convention here.  */

>> -

>> -int

>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>> -{

>> -  unsigned long int setval;

>> -  long result;

>> -

>> -  if (set)

>> -    setval = set->__val[0];

>> -  else

>> -    {

>> -      setval = 0;

>> -      how = SIG_BLOCK;	/* ensure blocked mask doesn't get changed */

>> -    }

>> -

>> -  result = INLINE_SYSCALL (osf_sigprocmask, 2, how, setval);

>> -  if (result == -1)

>> -    /* If there are ever more than 63 signals, we need to recode this

>> -       in assembler since we wouldn't be able to distinguish a mask of

>> -       all 1s from -1, but for now, we're doing just fine... */

>> -    return result;

>> -

>> -  if (oset)

>> -    {

>> -      oset->__val[0] = result;

>> -      result = _SIGSET_NWORDS;

>> -      while (--result > 0)

>> -	oset->__val[result] = 0;

>> -    }

>> -  return 0;

>> -}

>> -

>> -libc_hidden_def (__sigprocmask)

>> -weak_alias (__sigprocmask, sigprocmask);

>> diff --git a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c b/sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>> deleted file mode 100644

>> index 920c5fd..0000000

>> --- a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>> +++ /dev/null

>> @@ -1,40 +0,0 @@

>> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

>> -   This file is part of the GNU C Library.

>> -   Linux/IA64 specific sigprocmask

>> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.

>> -

>> -   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/>.  */

>> -

>> -/* Linux/ia64 only has rt signals, thus we do not even want to try falling

>> -   back to the old style signals as the default Linux handler does. */

>> -

>> -#include <errno.h>

>> -#include <signal.h>

>> -#include <unistd.h>

>> -

>> -#include <sysdep.h>

>> -#include <sys/syscall.h>

>> -

>> -/* Get and/or change the set of blocked signals.  */

>> -int

>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>> -{

>> -

>> -  /* XXX The size argument hopefully will have to be changed to the

>> -     real size of the user-level sigset_t.  */

>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>> -}

>> -libc_hidden_def (__sigprocmask)

>> -weak_alias (__sigprocmask, sigprocmask)

>> diff --git a/sysdeps/unix/sysv/linux/internal-signals.h b/sysdeps/unix/sysv/linux/internal-signals.h

>> index e96a718..bb8234d 100644

>> --- a/sysdeps/unix/sysv/linux/internal-signals.h

>> +++ b/sysdeps/unix/sysv/linux/internal-signals.h

>> @@ -36,6 +36,12 @@

>>  #define SIGSETXID       (__SIGRTMIN + 1)

>>  

>>  

>> +static inline bool

>> +__has_internal_signal (const sigset_t *set)

>> +{

>> +  return __sigismember (set, SIGCANCEL) || __sigismember (set, SIGSETXID);

>> +}

>> +

>>  /* Return is sig is used internally.  */

>>  static inline int

>>  __is_internal_signal (int sig)

>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c b/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>> deleted file mode 100644

>> index a8010e7..0000000

>> --- a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>> +++ /dev/null

>> @@ -1,38 +0,0 @@

>> -/* Copyright (C) 2001-2017 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/>.  */

>> -

>> -/* 64 bit Linux for S/390 only has rt signals, thus we do not even want to try

>> -   falling back to the old style signals as the default Linux handler does. */

>> -

>> -#include <errno.h>

>> -#include <signal.h>

>> -#include <unistd.h>

>> -

>> -#include <sysdep.h>

>> -#include <sys/syscall.h>

>> -

>> -/* Get and/or change the set of blocked signals.  */

>> -int

>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>> -{

>> -

>> -  /* XXX The size argument hopefully will have to be changed to the

>> -     real size of the user-level sigset_t.  */

>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>> -}

>> -libc_hidden_def (__sigprocmask)

>> -weak_alias (__sigprocmask, sigprocmask)

>> diff --git a/sysdeps/unix/sysv/linux/sigprocmask.c b/sysdeps/unix/sysv/linux/sigprocmask.c

>> index e776563..e574b5d 100644

>> --- a/sysdeps/unix/sysv/linux/sigprocmask.c

>> +++ b/sysdeps/unix/sysv/linux/sigprocmask.c

>> @@ -1,4 +1,5 @@

>> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

>> +/* Get and/or change the set of blocked signals.  Linux version.

>> +   Copyright (C) 1997-2017 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

>> @@ -17,34 +18,22 @@

>>  

>>  #include <errno.h>

>>  #include <signal.h>

>> -#include <string.h>  /* Needed for string function builtin redirection.  */

>> -#include <unistd.h>

>> +#include <internal-signals.h>

>>  

>> -#include <sysdep.h>

>> -#include <sys/syscall.h>

>>  

>> -#include <nptl/pthreadP.h>              /* SIGCANCEL, SIGSETXID */

>> -

>> -

>> -/* Get and/or change the set of blocked signals.  */

>>  int

>>  __sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>  {

>>    sigset_t local_newmask;

>>  

>> -  /* The only thing we have to make sure here is that SIGCANCEL and

>> -     SIGSETXID are not blocked.  */

>> -  if (set != NULL

>> -      && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)

>> -	  || __builtin_expect (__sigismember (set, SIGSETXID), 0)))

>> +  if (set != NULL && __glibc_unlikely (__has_internal_signal (set)))

>>      {

>>        local_newmask = *set;

>> -      __sigdelset (&local_newmask, SIGCANCEL);

>> -      __sigdelset (&local_newmask, SIGSETXID);

>> +      __clear_internal_signals (&local_newmask);

>>        set = &local_newmask;

>>      }

>>  

>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>> +  return INLINE_SYSCALL_CALL (rt_sigprocmask, how, set, oset, _NSIG / 8);

>>  }

>>  libc_hidden_def (__sigprocmask)

>>  weak_alias (__sigprocmask, sigprocmask)

>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c b/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>> deleted file mode 100644

>> index ef7d7fe..0000000

>> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>> +++ /dev/null

>> @@ -1,34 +0,0 @@

>> -/* Copyright (C) 1997-2017 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 <errno.h>

>> -#include <signal.h>

>> -#include <unistd.h>

>> -

>> -#include <sysdep.h>

>> -#include <sys/syscall.h>

>> -

>> -/* Get and/or change the set of blocked signals.  */

>> -int

>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>> -{

>> -  /* XXX The size argument hopefully will have to be changed to the

>> -     real size of the user-level sigset_t.  */

>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>> -}

>> -libc_hidden_def (__sigprocmask)

>> -weak_alias (__sigprocmask, sigprocmask)

>> diff --git a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c b/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

>> deleted file mode 100644

>> index 1610ddf..0000000

>> --- a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

>> +++ /dev/null

>> @@ -1,39 +0,0 @@

>> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

>> -   This file is part of the GNU C Library.

>> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.

>> -

>> -   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/>.  */

>> -

>> -/* Linux/x86_64 only has rt signals, thus we do not even want to try falling

>> -   back to the old style signals as the default Linux handler does. */

>> -

>> -#include <errno.h>

>> -#include <signal.h>

>> -#include <unistd.h>

>> -

>> -#include <sysdep.h>

>> -#include <sys/syscall.h>

>> -

>> -/* Get and/or change the set of blocked signals.  */

>> -int

>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>> -{

>> -

>> -  /* XXX The size argument hopefully will have to be changed to the

>> -     real size of the user-level sigset_t.  */

>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>> -}

>> -libc_hidden_def (__sigprocmask)

>> -weak_alias (__sigprocmask, sigprocmask)

>>
Adhemerval Zanella Jan. 17, 2018, 11:17 a.m. | #6
Ping.

On 01/01/2018 19:56, Adhemerval Zanella wrote:
> Ping.

> 

> On 12/12/2017 15:03, Adhemerval Zanella wrote:

>> Ping (with Rical suggested changes).

>>

>> On 15/11/2017 15:54, Adhemerval Zanella wrote:

>>> Changes from previous version:

>>>

>>>   - Cleanup __nptl prefix from the generic names.

>>>

>>> ---

>>>

>>> This patch consolidates the sigprocmask Linux syscall implementation on

>>> sysdeps/unix/sysv/linux/sigprocmask.c.  The changes are:

>>>

>>>   1. For ia64, s390-64, sparc64, and x86_64 the default semantic for

>>>      filter out SIGCANCEL and SIGSETXID is used.  Also the Linux pthread

>>>      semantic is documented in the signal chapter.

>>>

>>>   2. A new internal function to check for NPTL internal signals within a

>>>      signal set is added (__has_internal_signal).  It is used to

>>>      simplify the default sigprocmask.c implementation.

>>>

>>> Checked on x86_64-linux-gnu.

>>>

>>> 	[BZ #22391]

>>> 	* manual/signal.texi: Add a note about internal pthread signals

>>> 	on Linux.

>>> 	* sysdeps/unix/sysv/linux/alpha/sigprocmask.c: Remove file.

>>> 	* sysdeps/unix/sysv/linux/ia64/sigprocmask.c: Likewise.

>>> 	* sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c: Likewise.

>>> 	* sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c: Likewise.

>>> 	* sysdeps/unix/sysv/linux/x86_64/sigprocmask.c: Likewise.

>>> 	* sysdeps/unix/sysv/linux/internal-signals.h

>>> 	(__has_internal_signal): New function.

>>> 	* sysdeps/unix/sysv/linux/sigprocmask.c (__sigprocmask):

>>> 	Use __has_internal_signal and __clear_internal_signals

>>> 	function.

>>>

>>> Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

>>> Signed-off-by: Zack Weinberg <zackw@panix.com>

>>> Reported-by: Yury Norov <ynorov@caviumnetworks.com>

>>> ---

>>>  ChangeLog                                          | 17 +++++++

>>>  manual/signal.texi                                 | 37 ++++++++++++++

>>>  sysdeps/unix/sysv/linux/alpha/sigprocmask.c        | 58 ----------------------

>>>  sysdeps/unix/sysv/linux/ia64/sigprocmask.c         | 40 ---------------

>>>  sysdeps/unix/sysv/linux/internal-signals.h         |  6 +++

>>>  sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c | 38 --------------

>>>  sysdeps/unix/sysv/linux/sigprocmask.c              | 23 +++------

>>>  .../unix/sysv/linux/sparc/sparc64/sigprocmask.c    | 34 -------------

>>>  sysdeps/unix/sysv/linux/x86_64/sigprocmask.c       | 39 ---------------

>>>  9 files changed, 66 insertions(+), 226 deletions(-)

>>>  delete mode 100644 sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>>>  delete mode 100644 sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>>>  delete mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>>>  delete mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>>>  delete mode 100644 sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

>>>

>>> diff --git a/manual/signal.texi b/manual/signal.texi

>>> index 9577ff0..4f0ef59 100644

>>> --- a/manual/signal.texi

>>> +++ b/manual/signal.texi

>>> @@ -235,6 +235,7 @@ defined.  Since the signal numbers are allocated consecutively,

>>>  * Job Control Signals::         Signals used to support job control.

>>>  * Operation Error Signals::     Used to report operational system errors.

>>>  * Miscellaneous Signals::       Miscellaneous Signals.

>>> +* Internally-Used Signals::     Signals used internally by the C library.

>>>  * Signal Messages::             Printing a message describing a signal.

>>>  @end menu

>>>  

>>> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.

>>>  The default action is to terminate the process.

>>>  @end deftypevr

>>>  

>>> +@deftypevr Macro int SIGRTMIN

>>> +@deftypevrx Macro int SIGRTMAX

>>> +@standards{POSIX.1, signal.h}

>>> +@cindex real-time signals

>>> +The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},

>>> +@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you

>>> +want.  In addition, these signals (and no others) are guaranteed to

>>> +support @dfn{real-time} signal semantics, which unfortunately this

>>> +manual does not yet document.

>>> +

>>> +Unlike all of the other signal number macros, @code{SIGRTMIN} and

>>> +@code{SIGRTMAX} are not compile-time constants, because some operating

>>> +systems make the number of real-time signals tunable on a

>>> +per-installation or even per-process basis.  However, POSIX guarantees

>>> +that there will be at least 8 signal numbers in this range.

>>> +

>>> +The default action for all signals in this range is to terminate the

>>> +process.

>>> +@end deftypevr

>>> +

>>>  @deftypevr Macro int SIGWINCH

>>>  @standards{BSD, signal.h}

>>>  Window size change.  This is generated on some systems (including GNU)

>>> @@ -817,6 +838,22 @@ to print some status information about the system and what the process

>>>  is doing.  Otherwise the default is to do nothing.

>>>  @end deftypevr

>>>  

>>> +@node Internally-Used Signals

>>> +@subsection Internally-Used Signals

>>> +@cindex internally used signals

>>> +

>>> +On some operating systems, @theglibc{} needs to use a few signals from

>>> +the ``true'' real-time range internally, to implement thread

>>> +cancellation, cross-thread effective ID synchronization, POSIX timer

>>> +management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and

>>> +@code{SIGRTMAX} to exclude these signals, and it also takes steps to

>>> +prevent application code from altering their state: @code{sigprocmask}

>>> +cannot block them and @code{sigaction} cannot redefine their handlers,

>>> +for instance.  Therefore, most programs do not need to know or care

>>> +about these signals.  We mainly document their existence for the sake

>>> +of anyone who has ever wondered why there is a gap between the

>>> +highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.

>>> +

>>>  @node Signal Messages

>>>  @subsection Signal Messages

>>>  @cindex signal messages

>>> diff --git a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c b/sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>>> deleted file mode 100644

>>> index ebec70c..0000000

>>> --- a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c

>>> +++ /dev/null

>>> @@ -1,58 +0,0 @@

>>> -/* Copyright (C) 1993-2017 Free Software Foundation, Inc.

>>> -   This file is part of the GNU C Library.

>>> -   Contributed by David Mosberger (davidm@azstarnet.com).

>>> -

>>> -   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 <errno.h>

>>> -#include <sysdep.h>

>>> -#include <signal.h>

>>> -

>>> -/* When there is kernel support for more than 64 signals, we'll have to

>>> -   switch to a new system call convention here.  */

>>> -

>>> -int

>>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>> -{

>>> -  unsigned long int setval;

>>> -  long result;

>>> -

>>> -  if (set)

>>> -    setval = set->__val[0];

>>> -  else

>>> -    {

>>> -      setval = 0;

>>> -      how = SIG_BLOCK;	/* ensure blocked mask doesn't get changed */

>>> -    }

>>> -

>>> -  result = INLINE_SYSCALL (osf_sigprocmask, 2, how, setval);

>>> -  if (result == -1)

>>> -    /* If there are ever more than 63 signals, we need to recode this

>>> -       in assembler since we wouldn't be able to distinguish a mask of

>>> -       all 1s from -1, but for now, we're doing just fine... */

>>> -    return result;

>>> -

>>> -  if (oset)

>>> -    {

>>> -      oset->__val[0] = result;

>>> -      result = _SIGSET_NWORDS;

>>> -      while (--result > 0)

>>> -	oset->__val[result] = 0;

>>> -    }

>>> -  return 0;

>>> -}

>>> -

>>> -libc_hidden_def (__sigprocmask)

>>> -weak_alias (__sigprocmask, sigprocmask);

>>> diff --git a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c b/sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>>> deleted file mode 100644

>>> index 920c5fd..0000000

>>> --- a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c

>>> +++ /dev/null

>>> @@ -1,40 +0,0 @@

>>> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

>>> -   This file is part of the GNU C Library.

>>> -   Linux/IA64 specific sigprocmask

>>> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.

>>> -

>>> -   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/>.  */

>>> -

>>> -/* Linux/ia64 only has rt signals, thus we do not even want to try falling

>>> -   back to the old style signals as the default Linux handler does. */

>>> -

>>> -#include <errno.h>

>>> -#include <signal.h>

>>> -#include <unistd.h>

>>> -

>>> -#include <sysdep.h>

>>> -#include <sys/syscall.h>

>>> -

>>> -/* Get and/or change the set of blocked signals.  */

>>> -int

>>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>> -{

>>> -

>>> -  /* XXX The size argument hopefully will have to be changed to the

>>> -     real size of the user-level sigset_t.  */

>>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>>> -}

>>> -libc_hidden_def (__sigprocmask)

>>> -weak_alias (__sigprocmask, sigprocmask)

>>> diff --git a/sysdeps/unix/sysv/linux/internal-signals.h b/sysdeps/unix/sysv/linux/internal-signals.h

>>> index e96a718..bb8234d 100644

>>> --- a/sysdeps/unix/sysv/linux/internal-signals.h

>>> +++ b/sysdeps/unix/sysv/linux/internal-signals.h

>>> @@ -36,6 +36,12 @@

>>>  #define SIGSETXID       (__SIGRTMIN + 1)

>>>  

>>>  

>>> +static inline bool

>>> +__has_internal_signal (const sigset_t *set)

>>> +{

>>> +  return __sigismember (set, SIGCANCEL) || __sigismember (set, SIGSETXID);

>>> +}

>>> +

>>>  /* Return is sig is used internally.  */

>>>  static inline int

>>>  __is_internal_signal (int sig)

>>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c b/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>>> deleted file mode 100644

>>> index a8010e7..0000000

>>> --- a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c

>>> +++ /dev/null

>>> @@ -1,38 +0,0 @@

>>> -/* Copyright (C) 2001-2017 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/>.  */

>>> -

>>> -/* 64 bit Linux for S/390 only has rt signals, thus we do not even want to try

>>> -   falling back to the old style signals as the default Linux handler does. */

>>> -

>>> -#include <errno.h>

>>> -#include <signal.h>

>>> -#include <unistd.h>

>>> -

>>> -#include <sysdep.h>

>>> -#include <sys/syscall.h>

>>> -

>>> -/* Get and/or change the set of blocked signals.  */

>>> -int

>>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>> -{

>>> -

>>> -  /* XXX The size argument hopefully will have to be changed to the

>>> -     real size of the user-level sigset_t.  */

>>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>>> -}

>>> -libc_hidden_def (__sigprocmask)

>>> -weak_alias (__sigprocmask, sigprocmask)

>>> diff --git a/sysdeps/unix/sysv/linux/sigprocmask.c b/sysdeps/unix/sysv/linux/sigprocmask.c

>>> index e776563..e574b5d 100644

>>> --- a/sysdeps/unix/sysv/linux/sigprocmask.c

>>> +++ b/sysdeps/unix/sysv/linux/sigprocmask.c

>>> @@ -1,4 +1,5 @@

>>> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

>>> +/* Get and/or change the set of blocked signals.  Linux version.

>>> +   Copyright (C) 1997-2017 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

>>> @@ -17,34 +18,22 @@

>>>  

>>>  #include <errno.h>

>>>  #include <signal.h>

>>> -#include <string.h>  /* Needed for string function builtin redirection.  */

>>> -#include <unistd.h>

>>> +#include <internal-signals.h>

>>>  

>>> -#include <sysdep.h>

>>> -#include <sys/syscall.h>

>>>  

>>> -#include <nptl/pthreadP.h>              /* SIGCANCEL, SIGSETXID */

>>> -

>>> -

>>> -/* Get and/or change the set of blocked signals.  */

>>>  int

>>>  __sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>>  {

>>>    sigset_t local_newmask;

>>>  

>>> -  /* The only thing we have to make sure here is that SIGCANCEL and

>>> -     SIGSETXID are not blocked.  */

>>> -  if (set != NULL

>>> -      && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)

>>> -	  || __builtin_expect (__sigismember (set, SIGSETXID), 0)))

>>> +  if (set != NULL && __glibc_unlikely (__has_internal_signal (set)))

>>>      {

>>>        local_newmask = *set;

>>> -      __sigdelset (&local_newmask, SIGCANCEL);

>>> -      __sigdelset (&local_newmask, SIGSETXID);

>>> +      __clear_internal_signals (&local_newmask);

>>>        set = &local_newmask;

>>>      }

>>>  

>>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>>> +  return INLINE_SYSCALL_CALL (rt_sigprocmask, how, set, oset, _NSIG / 8);

>>>  }

>>>  libc_hidden_def (__sigprocmask)

>>>  weak_alias (__sigprocmask, sigprocmask)

>>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c b/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>>> deleted file mode 100644

>>> index ef7d7fe..0000000

>>> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c

>>> +++ /dev/null

>>> @@ -1,34 +0,0 @@

>>> -/* Copyright (C) 1997-2017 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 <errno.h>

>>> -#include <signal.h>

>>> -#include <unistd.h>

>>> -

>>> -#include <sysdep.h>

>>> -#include <sys/syscall.h>

>>> -

>>> -/* Get and/or change the set of blocked signals.  */

>>> -int

>>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>> -{

>>> -  /* XXX The size argument hopefully will have to be changed to the

>>> -     real size of the user-level sigset_t.  */

>>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>>> -}

>>> -libc_hidden_def (__sigprocmask)

>>> -weak_alias (__sigprocmask, sigprocmask)

>>> diff --git a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c b/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

>>> deleted file mode 100644

>>> index 1610ddf..0000000

>>> --- a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c

>>> +++ /dev/null

>>> @@ -1,39 +0,0 @@

>>> -/* Copyright (C) 1997-2017 Free Software Foundation, Inc.

>>> -   This file is part of the GNU C Library.

>>> -   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.

>>> -

>>> -   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/>.  */

>>> -

>>> -/* Linux/x86_64 only has rt signals, thus we do not even want to try falling

>>> -   back to the old style signals as the default Linux handler does. */

>>> -

>>> -#include <errno.h>

>>> -#include <signal.h>

>>> -#include <unistd.h>

>>> -

>>> -#include <sysdep.h>

>>> -#include <sys/syscall.h>

>>> -

>>> -/* Get and/or change the set of blocked signals.  */

>>> -int

>>> -__sigprocmask (int how, const sigset_t *set, sigset_t *oset)

>>> -{

>>> -

>>> -  /* XXX The size argument hopefully will have to be changed to the

>>> -     real size of the user-level sigset_t.  */

>>> -  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);

>>> -}

>>> -libc_hidden_def (__sigprocmask)

>>> -weak_alias (__sigprocmask, sigprocmask)

>>>

Patch

diff --git a/manual/signal.texi b/manual/signal.texi
index 9577ff0..4f0ef59 100644
--- a/manual/signal.texi
+++ b/manual/signal.texi
@@ -235,6 +235,7 @@  defined.  Since the signal numbers are allocated consecutively,
 * Job Control Signals::         Signals used to support job control.
 * Operation Error Signals::     Used to report operational system errors.
 * Miscellaneous Signals::       Miscellaneous Signals.
+* Internally-Used Signals::     Signals used internally by the C library.
 * Signal Messages::             Printing a message describing a signal.
 @end menu
 
@@ -794,6 +795,26 @@  in @ref{Signaling Another Process}.
 The default action is to terminate the process.
 @end deftypevr
 
+@deftypevr Macro int SIGRTMIN
+@deftypevrx Macro int SIGRTMAX
+@standards{POSIX.1, signal.h}
+@cindex real-time signals
+The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},
+@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you
+want.  In addition, these signals (and no others) are guaranteed to
+support @dfn{real-time} signal semantics, which unfortunately this
+manual does not yet document.
+
+Unlike all of the other signal number macros, @code{SIGRTMIN} and
+@code{SIGRTMAX} are not compile-time constants, because some operating
+systems make the number of real-time signals tunable on a
+per-installation or even per-process basis.  However, POSIX guarantees
+that there will be at least 8 signal numbers in this range.
+
+The default action for all signals in this range is to terminate the
+process.
+@end deftypevr
+
 @deftypevr Macro int SIGWINCH
 @standards{BSD, signal.h}
 Window size change.  This is generated on some systems (including GNU)
@@ -817,6 +838,22 @@  to print some status information about the system and what the process
 is doing.  Otherwise the default is to do nothing.
 @end deftypevr
 
+@node Internally-Used Signals
+@subsection Internally-Used Signals
+@cindex internally used signals
+
+On some operating systems, @theglibc{} needs to use a few signals from
+the ``true'' real-time range internally, to implement thread
+cancellation, cross-thread effective ID synchronization, POSIX timer
+management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and
+@code{SIGRTMAX} to exclude these signals, and it also takes steps to
+prevent application code from altering their state: @code{sigprocmask}
+cannot block them and @code{sigaction} cannot redefine their handlers,
+for instance.  Therefore, most programs do not need to know or care
+about these signals.  We mainly document their existence for the sake
+of anyone who has ever wondered why there is a gap between the
+highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.
+
 @node Signal Messages
 @subsection Signal Messages
 @cindex signal messages
diff --git a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c b/sysdeps/unix/sysv/linux/alpha/sigprocmask.c
deleted file mode 100644
index ebec70c..0000000
--- a/sysdeps/unix/sysv/linux/alpha/sigprocmask.c
+++ /dev/null
@@ -1,58 +0,0 @@ 
-/* Copyright (C) 1993-2017 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by David Mosberger (davidm@azstarnet.com).
-
-   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 <errno.h>
-#include <sysdep.h>
-#include <signal.h>
-
-/* When there is kernel support for more than 64 signals, we'll have to
-   switch to a new system call convention here.  */
-
-int
-__sigprocmask (int how, const sigset_t *set, sigset_t *oset)
-{
-  unsigned long int setval;
-  long result;
-
-  if (set)
-    setval = set->__val[0];
-  else
-    {
-      setval = 0;
-      how = SIG_BLOCK;	/* ensure blocked mask doesn't get changed */
-    }
-
-  result = INLINE_SYSCALL (osf_sigprocmask, 2, how, setval);
-  if (result == -1)
-    /* If there are ever more than 63 signals, we need to recode this
-       in assembler since we wouldn't be able to distinguish a mask of
-       all 1s from -1, but for now, we're doing just fine... */
-    return result;
-
-  if (oset)
-    {
-      oset->__val[0] = result;
-      result = _SIGSET_NWORDS;
-      while (--result > 0)
-	oset->__val[result] = 0;
-    }
-  return 0;
-}
-
-libc_hidden_def (__sigprocmask)
-weak_alias (__sigprocmask, sigprocmask);
diff --git a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c b/sysdeps/unix/sysv/linux/ia64/sigprocmask.c
deleted file mode 100644
index 920c5fd..0000000
--- a/sysdeps/unix/sysv/linux/ia64/sigprocmask.c
+++ /dev/null
@@ -1,40 +0,0 @@ 
-/* Copyright (C) 1997-2017 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Linux/IA64 specific sigprocmask
-   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.
-
-   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/>.  */
-
-/* Linux/ia64 only has rt signals, thus we do not even want to try falling
-   back to the old style signals as the default Linux handler does. */
-
-#include <errno.h>
-#include <signal.h>
-#include <unistd.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-/* Get and/or change the set of blocked signals.  */
-int
-__sigprocmask (int how, const sigset_t *set, sigset_t *oset)
-{
-
-  /* XXX The size argument hopefully will have to be changed to the
-     real size of the user-level sigset_t.  */
-  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);
-}
-libc_hidden_def (__sigprocmask)
-weak_alias (__sigprocmask, sigprocmask)
diff --git a/sysdeps/unix/sysv/linux/internal-signals.h b/sysdeps/unix/sysv/linux/internal-signals.h
index e96a718..bb8234d 100644
--- a/sysdeps/unix/sysv/linux/internal-signals.h
+++ b/sysdeps/unix/sysv/linux/internal-signals.h
@@ -36,6 +36,12 @@ 
 #define SIGSETXID       (__SIGRTMIN + 1)
 
 
+static inline bool
+__has_internal_signal (const sigset_t *set)
+{
+  return __sigismember (set, SIGCANCEL) || __sigismember (set, SIGSETXID);
+}
+
 /* Return is sig is used internally.  */
 static inline int
 __is_internal_signal (int sig)
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c b/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c
deleted file mode 100644
index a8010e7..0000000
--- a/sysdeps/unix/sysv/linux/s390/s390-64/sigprocmask.c
+++ /dev/null
@@ -1,38 +0,0 @@ 
-/* Copyright (C) 2001-2017 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/>.  */
-
-/* 64 bit Linux for S/390 only has rt signals, thus we do not even want to try
-   falling back to the old style signals as the default Linux handler does. */
-
-#include <errno.h>
-#include <signal.h>
-#include <unistd.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-/* Get and/or change the set of blocked signals.  */
-int
-__sigprocmask (int how, const sigset_t *set, sigset_t *oset)
-{
-
-  /* XXX The size argument hopefully will have to be changed to the
-     real size of the user-level sigset_t.  */
-  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);
-}
-libc_hidden_def (__sigprocmask)
-weak_alias (__sigprocmask, sigprocmask)
diff --git a/sysdeps/unix/sysv/linux/sigprocmask.c b/sysdeps/unix/sysv/linux/sigprocmask.c
index e776563..e574b5d 100644
--- a/sysdeps/unix/sysv/linux/sigprocmask.c
+++ b/sysdeps/unix/sysv/linux/sigprocmask.c
@@ -1,4 +1,5 @@ 
-/* Copyright (C) 1997-2017 Free Software Foundation, Inc.
+/* Get and/or change the set of blocked signals.  Linux version.
+   Copyright (C) 1997-2017 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
@@ -17,34 +18,22 @@ 
 
 #include <errno.h>
 #include <signal.h>
-#include <string.h>  /* Needed for string function builtin redirection.  */
-#include <unistd.h>
+#include <internal-signals.h>
 
-#include <sysdep.h>
-#include <sys/syscall.h>
 
-#include <nptl/pthreadP.h>              /* SIGCANCEL, SIGSETXID */
-
-
-/* Get and/or change the set of blocked signals.  */
 int
 __sigprocmask (int how, const sigset_t *set, sigset_t *oset)
 {
   sigset_t local_newmask;
 
-  /* The only thing we have to make sure here is that SIGCANCEL and
-     SIGSETXID are not blocked.  */
-  if (set != NULL
-      && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
-	  || __builtin_expect (__sigismember (set, SIGSETXID), 0)))
+  if (set != NULL && __glibc_unlikely (__has_internal_signal (set)))
     {
       local_newmask = *set;
-      __sigdelset (&local_newmask, SIGCANCEL);
-      __sigdelset (&local_newmask, SIGSETXID);
+      __clear_internal_signals (&local_newmask);
       set = &local_newmask;
     }
 
-  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);
+  return INLINE_SYSCALL_CALL (rt_sigprocmask, how, set, oset, _NSIG / 8);
 }
 libc_hidden_def (__sigprocmask)
 weak_alias (__sigprocmask, sigprocmask)
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c b/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c
deleted file mode 100644
index ef7d7fe..0000000
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/sigprocmask.c
+++ /dev/null
@@ -1,34 +0,0 @@ 
-/* Copyright (C) 1997-2017 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 <errno.h>
-#include <signal.h>
-#include <unistd.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-/* Get and/or change the set of blocked signals.  */
-int
-__sigprocmask (int how, const sigset_t *set, sigset_t *oset)
-{
-  /* XXX The size argument hopefully will have to be changed to the
-     real size of the user-level sigset_t.  */
-  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);
-}
-libc_hidden_def (__sigprocmask)
-weak_alias (__sigprocmask, sigprocmask)
diff --git a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c b/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c
deleted file mode 100644
index 1610ddf..0000000
--- a/sysdeps/unix/sysv/linux/x86_64/sigprocmask.c
+++ /dev/null
@@ -1,39 +0,0 @@ 
-/* Copyright (C) 1997-2017 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.
-
-   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/>.  */
-
-/* Linux/x86_64 only has rt signals, thus we do not even want to try falling
-   back to the old style signals as the default Linux handler does. */
-
-#include <errno.h>
-#include <signal.h>
-#include <unistd.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-/* Get and/or change the set of blocked signals.  */
-int
-__sigprocmask (int how, const sigset_t *set, sigset_t *oset)
-{
-
-  /* XXX The size argument hopefully will have to be changed to the
-     real size of the user-level sigset_t.  */
-  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);
-}
-libc_hidden_def (__sigprocmask)
-weak_alias (__sigprocmask, sigprocmask)