From nobody Tue Apr 7 07:34:16 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 325A2F507 for ; Sun, 15 Mar 2026 06:15:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773555354; cv=none; b=u+5SMNZ+ID7yLnZKgOb+TI8s+0LMjflNVtciMsAhssUSa8lqJmf9j2q1C5S7sz5H6KJNLv0SYi6RvwCbIfTw0siOngXVIR32lgftJBVTLsk7D26T0XZqc1wYriUpTkpoe/IcZvEi/QPcIE/8M+yIqi5s4Q9xiKp2pUwzXG0UVHo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773555354; c=relaxed/simple; bh=2bOs3M/w/wVwUIcNA9+TQbXWvEmLFoSCdguOxxeTa/s=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=G03jLDjSdiBBUxgoUcGNlR7gIHwG0HWeJSqfQQXFxt0YPcqMhBzAy1OHc4/s+xATbO4Bk7DlarJ3FTojEZaGubTdsY5739ESt3sc3iofy24YMsHJdmck7QsybS6IUT5c7wgM9ZnTyCItOLUZtnF3n8l2919AiS3HRaMY8dLh5o4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=f25r/Wc2; arc=none smtp.client-ip=220.197.31.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="f25r/Wc2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=2Z XrhsOgjkrmqiFmYgkPWo256bNtg6JmkHxFHSed3AQ=; b=f25r/Wc27aWloKm8bI +759Ta5Gs0Jc567OtnqWzamn7ykEf3VMDtIPfCL5J6Xx3MnIGeDirOdC9Krw089i 4C3UpWf+v/iKunYn2jgdwd/a7062J2+wvXc7SMbr9TnHJb494SFdRt1N5c66hWcS PUXFSr+vV0QSTdOhTg+fAHQEg= Received: from localhost.localdomain (unknown []) by gzsmtp1 (Coremail) with SMTP id PCgvCgBHNfVcTrZpPyEoRg--.15228S2; Sun, 15 Mar 2026 14:14:54 +0800 (CST) From: guoqi0226 To: anna-maria@linutronix.de, frederic@kernel.org, tglx@kernel.org Cc: bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, guoqi0226@163.com Subject: [PATCH v1] hrtimer: Fix is_hard/is_soft both false with missing HARD/SOFT flag Date: Sun, 15 Mar 2026 14:14:50 +0800 Message-Id: <20260315061450.129657-1-guoqi0226@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: PCgvCgBHNfVcTrZpPyEoRg--.15228S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7trW3Kr45ury5XFWUGr4xtFb_yoW8Cw1rpr WxJrWfK3y7XF4jyFW8AF9rGrZrtan3J3WxuFyrJ392ywn7t340qa1vg3Z8XFWaqrZ8urWx ArW0qr15CFWkZwUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0piTmh5UUUUU= X-CM-SenderInfo: 5jxr1xaqsslqqrwthudrp/xtbC4h6yG2m2Tl7VYQAA3u Content-Type: text/plain; charset="utf-8" When hrtimer mode is only ABS/REL (e.g. HRTIMER_MODE_ABS) with no explicit SOFT/HARD flag, and CONFIG_PREEMPT_RT is disabled, both timer->is_hard and is_soft become false, violating the hard/soft exclusive design rule. Enforce correct hard/soft timer via effective_mode: - Enable softtimer when CONFIG_PREEMPT_RT is enabled and no HARD flag - Add HRTIMER_MODE_HARD to effective_mode when CONFIG_PREEMPT_RT is disabled (e.g. HRTIMER_MODE_ABS) - Compute timer->is_hard as !!(effective_mode & HRTIMER_MODE_HARD) This ensures exactly one of is_hard/is_soft is true. Signed-off-by: guoqi0226 --- kernel/time/hrtimer.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 860af7a58428..5107d2e69887 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1618,6 +1618,7 @@ static void __hrtimer_setup(struct hrtimer *timer, { bool softtimer =3D !!(mode & HRTIMER_MODE_SOFT); struct hrtimer_cpu_base *cpu_base; + hrtimer_mode effective_mode =3D mode; int base; =20 /* @@ -1628,6 +1629,9 @@ static void __hrtimer_setup(struct hrtimer *timer, */ if (IS_ENABLED(CONFIG_PREEMPT_RT) && !(mode & HRTIMER_MODE_HARD)) softtimer =3D true; + else if (!IS_ENABLED(CONFIG_PREEMPT_RT) && !(mode & HRTIMER_MODE_HARD) && + !(mode & HRTIMER_MODE_SOFT)) + effective_mode |=3D HRTIMER_MODE_HARD; =20 memset(timer, 0, sizeof(struct hrtimer)); =20 @@ -1644,7 +1648,7 @@ static void __hrtimer_setup(struct hrtimer *timer, base =3D softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; base +=3D hrtimer_clockid_to_base(clock_id); timer->is_soft =3D softtimer; - timer->is_hard =3D !!(mode & HRTIMER_MODE_HARD); + timer->is_hard =3D !!(effective_mode & HRTIMER_MODE_HARD); timer->base =3D &cpu_base->clock_base[base]; timerqueue_init(&timer->node); =20 --=20 2.25.1