From nobody Mon Apr 21 03:19:27 2025 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4ZgrFW51b0z5snB0; Mon, 21 Apr 2025 03:19:27 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R10" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4ZgrFW3w0zz4138; Mon, 21 Apr 2025 03:19:27 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1745205567; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=b0E5cYiELjgCuqJHZF4KKHygeKdLvFENFxqvaiaWCNw=; b=Zy5xtKBf6eHBmppVivCoybbvKzGHFZk8yrxxnCniPl955hGklouxz1fgSbK6GR+zD+oBlo R+ia8miRjVxd31rMhwGBsjGdXz1539ucaQks6+362kJ3r3d4hXLiZw8bpHGznvvZ5K0prd VRZLjOFtsiMn7lLRK7oK2m0tSjcKIt0XDpOjVfknEAozduGXRvBvz9+/RfhBXHy8nbryi7 PvzWpeLaVafn4T0G0shi16lLm7cggXeyhfe10EB/tqFawYPyWSNzyp9L2rVtj9SH2jYJOd o2+SSMWkKYMmIdOo7SXL8jw4f+2CJSfYksiTly/QCNUMMYta2YqDvawzXu0I9w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1745205567; a=rsa-sha256; cv=none; b=VhO/SlsCezXevP+epzWlCyjlRn6S+PiC+cdqtLj03jVYZHn/P6r+tIXo/Veys3Gly06OcL aF6JPKupbK7GllDyPzSK3MBQZtbulu5cOIxoNtcFiowcS+bZGvad2kCx19ao8E6zAPi9KV U/AcqH8mGqUkzGpwXBbodNcPsniCCNGh3y42PpcknVnPvhR9k2RLHLCZbSPLVwPe99JWX5 aNqkvXU4lPnfphNXJvYHqnOjfalPVLZZRLQPAbJRUPUKTYFRpj+HqDXxf3oxjsBgRY6MJV u0kYp+uOFBfPWYhnpPM84JHKph+OzP6ggLbyEYt0UHkuX0N5cZMdb9XQlVUYkA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1745205567; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=b0E5cYiELjgCuqJHZF4KKHygeKdLvFENFxqvaiaWCNw=; b=NLcy24GzVoZ+pebePqGr76yQn2fvx0GivsBi5QZWiMX5q+oXD/LR4olaLqUy1aLMwdyTT5 hrxFbYHrPBvAZJvkXOK3Zp40AChumOgokenng2hHtxePuIHFLHs0d/NesA/4ovfUA1ia2/ H08pZx4bdz7Xi3G8CbzoEkKQGoARO1FxSkGOQu05TMg6BUdt5QiXPlSIL9rofen3RF6OlY RTR942fN4909vQRf1wuflCiOLQkLMaLzNlz+rMefQu3zblHyY/Ms2FyJ2vAa4Ey/lR9lbn mLjRsrhKTHJWPr1Jgikq4/Sukvmlb49eONR/pZHtOAYvmWEmR9yKc/ro0c1ReQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4ZgrFW3WRJzYn6; Mon, 21 Apr 2025 03:19:27 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 53L3JRDJ006547; Mon, 21 Apr 2025 03:19:27 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 53L3JRSL006544; Mon, 21 Apr 2025 03:19:27 GMT (envelope-from git) Date: Mon, 21 Apr 2025 03:19:27 GMT Message-Id: <202504210319.53L3JRSL006544@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Kyle Evans Subject: git: df1b0f580d3d - main - time: switch to fences for siginfo_recvd List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kevans X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: df1b0f580d3dc4dd165d84fbcc14d0eebd8ee2c4 Auto-Submitted: auto-generated The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=df1b0f580d3dc4dd165d84fbcc14d0eebd8ee2c4 commit df1b0f580d3dc4dd165d84fbcc14d0eebd8ee2c4 Author: Kyle Evans AuthorDate: 2025-04-21 03:19:17 +0000 Commit: Kyle Evans CommitDate: 2025-04-21 03:19:17 +0000 time: switch to fences for siginfo_recvd This effectively reverts 6e824f3713011 ("time: siginfo_recvd needs to be marked volatile") because it was actually wrong. Switch to C11 signal fence, which provides a compiler barrier that will do the right thing. Reported by: kib Reviewed by: kib (slightly earlier version) Differential Revision: https://reviews.freebsd.org/D45574 --- usr.bin/time/time.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/usr.bin/time/time.c b/usr.bin/time/time.c index 4c1ce06543e3..5478b23d52ec 100644 --- a/usr.bin/time/time.c +++ b/usr.bin/time/time.c @@ -40,6 +40,8 @@ #include #include #include +#include +#include #include #include #include @@ -54,7 +56,7 @@ static void showtime(FILE *, struct timespec *, struct timespec *, static void siginfo(int); static void usage(void) __dead2; -static volatile sig_atomic_t siginfo_recvd; +static sig_atomic_t siginfo_recvd; static char decimal_point; static struct timespec before_ts; static int hflag, pflag; @@ -125,7 +127,10 @@ main(int argc, char **argv) (void)signal(SIGINFO, siginfo); (void)siginterrupt(SIGINFO, 1); while (wait4(pid, &status, 0, &ru) != pid) { - if (siginfo_recvd) { + bool do_siginfo = siginfo_recvd != 0; + + atomic_signal_fence(memory_order_acquire); + if (do_siginfo) { siginfo_recvd = 0; if (clock_gettime(CLOCK_MONOTONIC, &after)) err(1, "clock_gettime"); @@ -296,4 +301,5 @@ siginfo(int sig __unused) { siginfo_recvd = 1; + atomic_signal_fence(memory_order_release); }