From patchwork Fri Oct 21 11:59:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felix Willgerodt X-Patchwork-Id: 59282 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 8BF51385382F for ; Fri, 21 Oct 2022 12:06:07 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8BF51385382F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1666353967; bh=j51JBo7mSxqh31m2ZzsE1dKiTuHV/VJGyJzC5VLWT2g=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=e/6n5u3V8j37AGo0OO4qvx8un6LdiH/PDE+0CXZcu87WbvrgjfH7Ko5eI+0IaHCQY OfMUcgZfzxvkGvdq6qsqj7ILVGmu2ZRf/kRREaJJGo2mtZ4jSTLUl3XjiqVk6Z+jhg nGVgmtmAYkS6EI2RPfDvzF4zIumGwfYLWE+HRJ4Y= X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by sourceware.org (Postfix) with ESMTPS id 43AC63853839 for ; Fri, 21 Oct 2022 12:02:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 43AC63853839 X-IronPort-AV: E=McAfee;i="6500,9779,10506"; a="308675187" X-IronPort-AV: E=Sophos;i="5.95,200,1661842800"; d="scan'208";a="308675187" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Oct 2022 05:02:56 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10506"; a="773013344" X-IronPort-AV: E=Sophos;i="5.95,200,1661842800"; d="scan'208";a="773013344" Received: from mulvlfelix.iul.intel.com (HELO localhost) ([172.28.48.92]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Oct 2022 05:02:55 -0700 To: gdb-patches@sourceware.org, markus.t.metzger@intel.com Subject: [PATCH v7 08/10] btrace, linux: Enable ptwrite packets. Date: Fri, 21 Oct 2022 13:59:45 +0200 Message-Id: <20221021115947.359223-9-felix.willgerodt@intel.com> X-Mailer: git-send-email 2.34.3 In-Reply-To: <20221021115947.359223-1-felix.willgerodt@intel.com> References: <20221021115947.359223-1-felix.willgerodt@intel.com> MIME-Version: 1.0 X-Spam-Status: No, score=-10.5 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Felix Willgerodt via Gdb-patches From: Felix Willgerodt Reply-To: Felix Willgerodt Errors-To: gdb-patches-bounces+patchwork=sourceware.org@sourceware.org Sender: "Gdb-patches" Enable ptwrite in the PT config, if it is supported by the kernel. --- gdb/nat/linux-btrace.c | 29 +++++++++++++++++++++++++++++ gdb/record-btrace.c | 5 +++++ 2 files changed, 34 insertions(+) diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c index 4911630ba5c..701ea948610 100644 --- a/gdb/nat/linux-btrace.c +++ b/gdb/nat/linux-btrace.c @@ -415,6 +415,29 @@ cpu_supports_bts (void) } } +/* Check whether the linux target supports Intel Processor Trace PTWRITE. */ + +static bool +linux_supports_ptwrite () +{ + static const char filename[] + = "/sys/bus/event_source/devices/intel_pt/caps/ptwrite"; + gdb_file_up file = gdb_fopen_cloexec (filename, "r"); + + if (file.get () == nullptr) + return false; + + int status, found = fscanf (file.get (), "%d", &status); + + if (found != 1) + { + warning (_("Failed to determine ptwrite support from %s."), filename); + return false; + } + + return status == 1; +} + /* The perf_event_open syscall failed. Try to print a helpful error message. */ @@ -624,6 +647,12 @@ linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) pt->attr.exclude_hv = 1; pt->attr.exclude_idle = 1; + if (conf->ptwrite && linux_supports_ptwrite ()) + { + pt->attr.config |= 0x1000; + tinfo->conf.pt.ptwrite = conf->ptwrite; + } + errno = 0; scoped_fd fd (syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0)); if (fd.get () < 0) diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c index 0767dd12fee..203d994a306 100644 --- a/gdb/record-btrace.c +++ b/gdb/record-btrace.c @@ -3286,4 +3286,9 @@ to see the actual buffer size."), NULL, show_record_pt_buffer_size_value, record_btrace_conf.bts.size = 64 * 1024; record_btrace_conf.pt.size = 16 * 1024; +#if (LIBIPT_VERSION >= 0x200) + record_btrace_conf.pt.ptwrite = true; +#else + record_btrace_conf.pt.ptwrite = false; +#endif }