From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C208A13049F; Sun, 26 May 2024 09:43:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716716614; cv=none; b=OpcClcigd6hln3N/o711WuRX7ZDSp0nZLEuYymu/JkJxbTXljz2bH+zWerDZbPorXCizZva88F5EtcKih+aJNNtnyMbWWrvB6rzvh+tqOV69/XBYUHrPKGEwaHa5FeJjFfzFVlucrIa8fDuH6AK92AawYMQOUve5OvvsnBVaHCM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716716614; c=relaxed/simple; bh=T55+DPkc3PTOXL6KvirvL0sLE62EmSCCbw5DZnTAuZ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EwRQ9i3Mgcf6xxzBwiY6J3MPPYhCdHj+BuR9Vmk3PaZruioH3jVZ3mHPka7xWABVI/Anvh3fwsxgZw+zHLeuzeh3/+lGMpZbbZBkC3WvkNnclCsXD4GLgHgF16MJuumYHFK8GG9Km76sZRqWsL++c6X/tGAGfXKE0vtQ4zraXZ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VCf3Ukl+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VCf3Ukl+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41757C32782; Sun, 26 May 2024 09:43:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716716614; bh=T55+DPkc3PTOXL6KvirvL0sLE62EmSCCbw5DZnTAuZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VCf3Ukl+r/Gm9gHh6twmhDpEYfUaPuOqmc6VjpOJXhGBcM4IOEP+bwEGyULyrZ2AH VZM3RRgipepomS3niwASZLoXZlOBg8wM8P9KpyLm7hy9pVGYRi1sy2zg15fX9+Lmy8 xq5E1lUA9OTG9LebTLPPlHxc4RY+HHsxzK5aEQ8Gn9u6ZeP0QiJUsbdnIWoMKhlxqQ GUl6tVxDDWV2/XjwraZXtQVK3FS3R8cfzp/OayEHrXf9DK5N/OTL2+m4d5b4Ga7vdm idYyddqGsVsH0qpLEMfL1o8jVWvsZm3vg7pZZ7DUhUhN8G4t79uTFaWHIao2mweajf chVk1+CWgQ6HA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Paul E. McKenney" , Linus Torvalds , Uladzislau Rezki , Sasha Levin , dave@stgolabs.net, josh@joshtriplett.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joel@joelfernandes.org, boqun.feng@gmail.com, rcu@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 3/7] rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment Date: Sun, 26 May 2024 05:43:23 -0400 Message-ID: <20240526094329.3413652-3-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240526094329.3413652-1-sashal@kernel.org> References: <20240526094329.3413652-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.159 Content-Transfer-Encoding: 8bit From: "Paul E. McKenney" [ Upstream commit 8b9b443fa860276822b25057cb3ff3b28734dec0 ] The "pipe_count > RCU_TORTURE_PIPE_LEN" check has a comment saying "Should not happen, but...". This is only true when testing an RCU whose grace periods are always long enough. This commit therefore fixes this comment. Reported-by: Linus Torvalds Closes: https://lore.kernel.org/lkml/CAHk-=wi7rJ-eGq+xaxVfzFEgbL9tdf6Kc8Z89rCpfcQOKm74Tw@mail.gmail.com/ Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Sasha Levin --- kernel/rcu/rcutorture.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index d820ef615475b..82c6046db8a42 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1604,7 +1604,8 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) preempt_disable(); pipe_count = READ_ONCE(p->rtort_pipe_count); if (pipe_count > RCU_TORTURE_PIPE_LEN) { - /* Should not happen, but... */ + // Should not happen in a correct RCU implementation, + // happens quite often for torture_type=busted. pipe_count = RCU_TORTURE_PIPE_LEN; } completed = cur_ops->get_gp_seq(); -- 2.43.0