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 8AA7614430D; Thu, 11 Apr 2024 10:02:35 +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=1712829755; cv=none; b=ZThPLBy2S/X7Ukn9b/a2DZ9TbgETxREv6VnO5VAfKKOImh+2+wtP98BFBiuBbFkrFCIBhsLofR0ayt8ZERU2CMz91QwH5CuHQThtPE+3ZG4yyIvaGvXwYvNwaIuTokmN6JCKXRK2ZRbwU2523RDtaOWnLJM9jdiBmTonlm37sm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712829755; c=relaxed/simple; bh=7pVZGUsoXK1v8X+d9P9gB+4szEczhw9f+5oL2U1gNkQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f4u/0JUWIlO8NW4qKH61l0ud75m65GFcS1VAPaeBJ28B2PgegC4YKb2QlRd7u+mU7pnY1FeTzq08g18QxMUAQK2ZDX4pIz/2Klaiz6nKdu1WUSoVq1zc+D6Er8LmuUkPsXNqfPgFpQwvBKcXj4WD/CXc9lY20JY/SVuCZM7yB1w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yMfqZLCm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yMfqZLCm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D0E3C433C7; Thu, 11 Apr 2024 10:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712829755; bh=7pVZGUsoXK1v8X+d9P9gB+4szEczhw9f+5oL2U1gNkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yMfqZLCmYDsiMIfkGSPSTpZ0dZFfTYtV/TssAxCYAsSMqRgRv9IgNcZfxsLuqgDBL 3CJvdDvswJp2pdx/6VqRfQT4GhCf+4ax1MJJiuinfYicZQSwzAFb5PBRhbpq01tg3c DktUtL4jfpa2UDVHZq8Plpg5dJ8iBKVyw3W85+a8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yang Jihong , "Peter Zijlstra (Intel)" , Thadeu Lima de Souza Cascardo Subject: [PATCH 4.19 095/175] perf/core: Fix reentry problem in perf_output_read_group() Date: Thu, 11 Apr 2024 11:55:18 +0200 Message-ID: <20240411095422.427434777@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095419.532012976@linuxfoundation.org> References: <20240411095419.532012976@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yang Jihong commit 6b959ba22d34ca793ffdb15b5715457c78e38b1a upstream. perf_output_read_group may respond to IPI request of other cores and invoke __perf_install_in_context function. As a result, hwc configuration is modified. causing inconsistency and unexpected consequences. Interrupts are not disabled when perf_output_read_group reads PMU counter. In this case, IPI request may be received from other cores. As a result, PMU configuration is modified and an error occurs when reading PMU counter: CPU0 CPU1 __se_sys_perf_event_open perf_install_in_context perf_output_read_group smp_call_function_single for_each_sibling_event(sub, leader) { generic_exec_single if ((sub != event) && remote_function (sub->state == PERF_EVENT_STATE_ACTIVE)) | <----RAISE IPI-----+ __perf_install_in_context ctx_resched event_sched_out armpmu_del ... hwc->idx = -1; // event->hwc.idx is set to -1 ... sub->pmu->read(sub); armpmu_read armv8pmu_read_counter armv8pmu_read_hw_counter int idx = event->hw.idx; // idx = -1 u64 val = armv8pmu_read_evcntr(idx); u32 counter = ARMV8_IDX_TO_COUNTER(idx); // invalid counter = 30 read_pmevcntrn(counter) // undefined instruction Signed-off-by: Yang Jihong Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220902082918.179248-1-yangjihong1@huawei.com Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6253,9 +6253,16 @@ static void perf_output_read_group(struc { struct perf_event *leader = event->group_leader, *sub; u64 read_format = event->attr.read_format; + unsigned long flags; u64 values[6]; int n = 0; + /* + * Disabling interrupts avoids all counter scheduling + * (context switches, timer based rotation and IPIs). + */ + local_irq_save(flags); + values[n++] = 1 + leader->nr_siblings; if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) @@ -6291,6 +6298,8 @@ static void perf_output_read_group(struc __output_copy(handle, values, n * sizeof(u64)); } + + local_irq_restore(flags); } #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\