From patchwork Mon Nov 6 13:37:02 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: 24109 Received: (qmail 33799 invoked by alias); 6 Nov 2017 13:37:24 -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 33699 invoked by uid 89); 6 Nov 2017 13:37:23 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-25.5 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=inclusion X-HELO: mail-qk0-f193.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:subject:date:message-id:in-reply-to :references; bh=vOE2kMdpnpEBKmGLTlceF7ohREHR0tG7juh2j0ecqWU=; b=pXbUyxYP8IOLfUqziuuUGliWN4KiLxP2NtkbCsW7Rf1hwMVjLZXNBOAhWmOkrdKDJO RjmQA8xz0aTYlEGQ8Ee7NSurIXSs6kcZj8QKvrlKiNd6G6c1SNuFMnCkCN4VS2gsaIVj d6t2V0Jr5o1eksdWbS7synIyM6EI+SEJQkrkwpzffKL0ooK0/08q/I4imKjiVfPcuMDO T3XyNFeox/tQnAayR7Je1fb+z/DvdDdX+1Hls07Jo4MhiteXuTas5dzPr8L6+OD4JxmR on2nT3LgdNkksulPhEiSQ0wDgXS4bh1Iz9NoYwqcXbPdixJmb3VdV6fdpQs5q8JiBB0m CNiQ== X-Gm-Message-State: AJaThX6ovK215zoChYnQrNLPKnoDz3mdwJtZ9AEo5qka02vJJiVtI+kh qvH/AeZdTu0meUcnNmz3zInAudBIk/g= X-Google-Smtp-Source: ABhQp+RM/tuKKzQXhu+GcA1iCLi2tTO1ygtdkLP1ujaOSEthSR5Ul2hU7BoNm8b5T1O1rB/OUq5R/A== X-Received: by 10.55.214.25 with SMTP id t25mr3185091qki.225.1509975439676; Mon, 06 Nov 2017 05:37:19 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH v2 4/8] Simplify Linux sig{timed}wait{info} implementations Date: Mon, 6 Nov 2017 11:37:02 -0200 Message-Id: <1509975426-1772-4-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: - Add a note about __NR_rt_sigtimedwait Linux minimum version support. - Comment about LIBC_CANCEL_HANDLED annotations. - Add a note about __sigtimedwait inclusion on GLIBC_PRIVATE. --- This patch simplifies sig{timed}wait{info} by: - Assuming __NR_rt_sigtimedwait existence on all architectures due minimum kernel version requirement (it pre-dates Linux git inclusion for Linux 2.6.12). - Now that sigwait is based on a internal sigtimedwait call and it is present of both libc.so and libpthread.so we need to add an external private definition of __sigtimedwait for libpthread.so call. - Call __sigtimedwait on both sigwait and sigwaitinfo. Checked on x86_64-linux-gnu. * sysdeps/unix/sysv/linux/Versions (libc) [GLIBC_PRIVATE]: Add __sigtimedwait. * sysdeps/unix/sysv/linux/sigtimedwait.c: Simplify includes and assume __NR_rt_sigtimedwait. * sysdeps/unix/sysv/linux/sigwait.c (__sigwait): Call __sigtimedwait and add LIBC_CANCEL_HANDLED for cancellation marking. * sysdeps/unix/sysv/linux/sigwaitinfo.c (__sigwaitinfo): Likewise. Signed-off-by: Adhemerval Zanella Reviewed-by: Zack Weinberg --- ChangeLog | 8 ++++ sysdeps/unix/sysv/linux/Versions | 1 + sysdeps/unix/sysv/linux/sigtimedwait.c | 9 ----- sysdeps/unix/sysv/linux/sigwait.c | 68 ++++------------------------------ sysdeps/unix/sysv/linux/sigwaitinfo.c | 41 ++------------------ 5 files changed, 21 insertions(+), 106 deletions(-) diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions index 6c9e06f..d3dbcde 100644 --- a/sysdeps/unix/sysv/linux/Versions +++ b/sysdeps/unix/sysv/linux/Versions @@ -172,6 +172,7 @@ libc { __open_nocancel; __read_nocancel; __close_nocancel; + __sigtimedwait; # functions used by nscd __netlink_assert_response; } diff --git a/sysdeps/unix/sysv/linux/sigtimedwait.c b/sysdeps/unix/sysv/linux/sigtimedwait.c index 21e9fca..f74a921 100644 --- a/sysdeps/unix/sysv/linux/sigtimedwait.c +++ b/sysdeps/unix/sysv/linux/sigtimedwait.c @@ -17,13 +17,7 @@ #include #include -#include - -#include #include -#include - -#ifdef __NR_rt_sigtimedwait int __sigtimedwait (const sigset_t *set, siginfo_t *info, @@ -44,6 +38,3 @@ __sigtimedwait (const sigset_t *set, siginfo_t *info, } libc_hidden_def (__sigtimedwait) weak_alias (__sigtimedwait, sigtimedwait) -#else -# include -#endif diff --git a/sysdeps/unix/sysv/linux/sigwait.c b/sysdeps/unix/sysv/linux/sigwait.c index 18a4485..e6fb32a 100644 --- a/sysdeps/unix/sysv/linux/sigwait.c +++ b/sysdeps/unix/sysv/linux/sigwait.c @@ -15,73 +15,21 @@ License along with the GNU C Library; if not, see . */ -#include #include -#define __need_NULL -#include -#include - -#include #include -#include - -#ifdef __NR_rt_sigtimedwait - -/* Return any pending signal or wait for one for the given time. */ -static int -do_sigwait (const sigset_t *set, int *sig) -{ - int ret; - - /* XXX The size argument hopefully will have to be changed to the - real size of the user-level sigset_t. */ -#ifdef INTERNAL_SYSCALL - INTERNAL_SYSCALL_DECL (err); - do - ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, set, - NULL, NULL, _NSIG / 8); - while (INTERNAL_SYSCALL_ERROR_P (ret, err) - && INTERNAL_SYSCALL_ERRNO (ret, err) == EINTR); - if (! INTERNAL_SYSCALL_ERROR_P (ret, err)) - { - *sig = ret; - ret = 0; - } - else - ret = INTERNAL_SYSCALL_ERRNO (ret, err); -#else - do - ret = INLINE_SYSCALL (rt_sigtimedwait, 4, set, NULL, NULL, _NSIG / 8); - while (ret == -1 && errno == EINTR); - if (ret != -1) - { - *sig = ret; - ret = 0; - } - else - ret = errno; -#endif - - return ret; -} int __sigwait (const sigset_t *set, int *sig) { - if (SINGLE_THREAD_P) - return do_sigwait (set, sig); - - int oldtype = LIBC_CANCEL_ASYNC (); - - int result = do_sigwait (set, sig); - - LIBC_CANCEL_RESET (oldtype); - - return result; + siginfo_t si; + if (__sigtimedwait (set, &si, 0) < 0) + return -1; + *sig = si.si_signo; + return 0; } libc_hidden_def (__sigwait) weak_alias (__sigwait, sigwait) -#else -# include -#endif strong_alias (__sigwait, __libc_sigwait) + +/* __sigtimedwait handles cancellation. */ +LIBC_CANCEL_HANDLED (); diff --git a/sysdeps/unix/sysv/linux/sigwaitinfo.c b/sysdeps/unix/sysv/linux/sigwaitinfo.c index 0062d3e..75ddd52 100644 --- a/sysdeps/unix/sysv/linux/sigwaitinfo.c +++ b/sysdeps/unix/sysv/linux/sigwaitinfo.c @@ -15,52 +15,19 @@ License along with the GNU C Library; if not, see . */ -#include #include -#define __need_NULL -#include -#include - -#include #include -#include - -#ifdef __NR_rt_sigtimedwait /* Return any pending signal or wait for one for the given time. */ int __sigwaitinfo (const sigset_t *set, siginfo_t *info) { - sigset_t tmpset; - if (set != NULL - && (__builtin_expect (__sigismember (set, SIGCANCEL), 0) - || __builtin_expect (__sigismember (set, SIGSETXID), 0))) - { - /* Create a temporary mask without the bit for SIGCANCEL set. */ - // We are not copying more than we have to. - memcpy (&tmpset, set, _NSIG / 8); - __sigdelset (&tmpset, SIGCANCEL); - __sigdelset (&tmpset, SIGSETXID); - set = &tmpset; - } - - /* XXX The size argument hopefully will have to be changed to the - real size of the user-level sigset_t. */ - int result = SYSCALL_CANCEL (rt_sigtimedwait, set, info, NULL, _NSIG / 8); - - /* The kernel generates a SI_TKILL code in si_code in case tkill is - used. tkill is transparently used in raise(). Since having - SI_TKILL as a code is useful in general we fold the results - here. */ - if (result != -1 && info != NULL && info->si_code == SI_TKILL) - info->si_code = SI_USER; - - return result; + return __sigtimedwait (set, info, 0); } libc_hidden_def (__sigwaitinfo) weak_alias (__sigwaitinfo, sigwaitinfo) -#else -# include -#endif strong_alias (__sigwaitinfo, __libc_sigwaitinfo) + +/* __sigtimedwait handles cancellation. */ +LIBC_CANCEL_HANDLED ();