From patchwork Mon Nov 6 13:37:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 24112 Received: (qmail 34193 invoked by alias); 6 Nov 2017 13:37:26 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 34086 invoked by uid 89); 6 Nov 2017 13:37:25 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-25.7 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=ham version=3.3.2 spammy=H*Ad:D*panix.com X-HELO: mail-qt0-f175.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=s+mUNdra0FcnGNQdgljxcJpOQ++RGvFO3nlG/Gyl8aY=; b=OtpfU1d/gElnhN1BT2X3d9Na9k4JTh4Zkt4V1Y7fuhncDb3k6i/V13tYrtg6s6c3F8 9BE+wW+LLjaqhFB2t/2TlJs5OqvqqsurKSfJGkpyHe69F7/+lTu1xNOsxxBAf0yCeSPJ ByE6auxWOGVqt0hiGc1+gzT0LstpMNf4ZgHjzHolLC3mhkA18WjUdt3TpkAurnrLk2e1 tTp6hNfBto2YbdDqO3cVLVh2fHQawlKa0UNsdtHkYP5Fgh1ryilhFtPewmGbgKteC+eq E8lN/wGl6e15FzHssvjPG3tJfTyrj0czABzCaf9/TH4v7mGy5LUUlo69mwLrL49Mfr2K vTkw== X-Gm-Message-State: AMCzsaVWAFHaGEwQzR/fWIR8rCAKf60yb+TN72SDVmqtAHz4k7jJGDNw SxUIsPCuu7pSmWFvDVhOd+Bnmcm8sCg= X-Google-Smtp-Source: ABhQp+Sk3OENTyCxFGoX6JYNz3EdmAmjFfIq6Q/O67dmsVHwGHzn8du1Bu+yqQl4ZfYzGFopdLXnEw== X-Received: by 10.200.63.156 with SMTP id d28mr23000221qtk.170.1509975436561; Mon, 06 Nov 2017 05:37:16 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Cc: Zack Weinberg Subject: [PATCH v2 2/8] Consolidate Linux sigprocmask implementation (BZ #22391) Date: Mon, 6 Nov 2017 11:37:00 -0200 Message-Id: <1509975426-1772-2-git-send-email-adhemerval.zanella@linaro.org> In-Reply-To: <1509975426-1772-1-git-send-email-adhemerval.zanella@linaro.org> References: <1509975426-1772-1-git-send-email-adhemerval.zanella@linaro.org> Changes from previous version: - Rewrite manual/signal.text based on Zack Weinberg suggestion. --- 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 (__nptl_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/ia64/sigprocmask.c: Remove file. * 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/nptl-signals.h (__nptl_has_internal_signal): New function. * sysdeps/unix/sysv/linux/sigprocmask.c (__sigprocmask): Use __nptl_has_internal_signal and __nptl_clear_internal_signals function. Signed-off-by: Adhemerval Zanella Signed-off-by: Zack Weinberg Reported-by: Yury Norov --- 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 - . */ - -#include -#include -#include - -/* 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, , 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 - . */ - -/* 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 -#include -#include - -#include -#include - -/* 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 797698b..ad9783b 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 +__nptl_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 - . */ - -/* 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 -#include -#include - -#include -#include - -/* 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..d14fc5c 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 #include -#include /* Needed for string function builtin redirection. */ -#include +#include -#include -#include -#include /* 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 (__nptl_has_internal_signal (set))) { local_newmask = *set; - __sigdelset (&local_newmask, SIGCANCEL); - __sigdelset (&local_newmask, SIGSETXID); + __nptl_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 - . */ - -#include -#include -#include - -#include -#include - -/* 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, , 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 - . */ - -/* 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 -#include -#include - -#include -#include - -/* 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)