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 34391140E3D; Thu, 11 Apr 2024 10:19:34 +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=1712830774; cv=none; b=CnlRq1vN/bT45oIrLVuxVEkreqoOKXGVEm5IYfvp7jCInvdo41mRUn6nqCCBfMTFoXk9zEP0teQT2G+aeD3qM/UrLd60i2XuANQvGHqZJCBIgAA5fvQXOFUxweqR5JCEiF8VgwF15GYHrxZcgfmbjOMrchEFje8CCCO00FIh/EU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712830774; c=relaxed/simple; bh=GL9oVYuPxfi3LLwUkIf37S1Ag54UlmwbVuAAl/uZ1dA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k++L1T3aiQT1yq9kAqKFPyXn5/+dZy3XfEPi/TDoIvm5A4ojO63Fy2k71FAFD0WpDS8aK5hBHYTvmpDRg1CBJQI7xpsKtvfaYmJybP3z5rvpZJoUlt8v/WgDd/x+yEh6Z3j9zY5Ar2SUjyC4Ab5U4T7usNm42pl/1qPJXHgyfMI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0XMrx9Jd; 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="0XMrx9Jd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACB78C433C7; Thu, 11 Apr 2024 10:19:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712830774; bh=GL9oVYuPxfi3LLwUkIf37S1Ag54UlmwbVuAAl/uZ1dA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0XMrx9JdBsM3mNoUZmddDTIDZxwI6BFwPsXLx5aNz+x77goaJdzMSQxOlo6LCoDiz OOanYmpA1R6LvcHvMOJvacermeqjT0TEQHmfTx/XrF4qQ5QrGb6KgdWvwGErCmWJJJ Je3L30546/m1lut9TfbgXKNo3LY6639P146iWyL8= 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 5.4 106/215] perf/core: Fix reentry problem in perf_output_read_group() Date: Thu, 11 Apr 2024 11:55:15 +0200 Message-ID: <20240411095428.097906923@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095424.875421572@linuxfoundation.org> References: <20240411095424.875421572@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 5.4-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 @@ -6372,9 +6372,16 @@ 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) @@ -6410,6 +6417,8 @@ 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|\