From patchwork Mon Oct 21 09:47:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11201697 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DCE991390 for ; Mon, 21 Oct 2019 09:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4FCE20830 for ; Mon, 21 Oct 2019 09:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727737AbfJUJrh (ORCPT ); Mon, 21 Oct 2019 05:47:37 -0400 Received: from mx2.suse.de ([195.135.220.15]:46482 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726725AbfJUJrg (ORCPT ); Mon, 21 Oct 2019 05:47:36 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E0EB2B8D8; Mon, 21 Oct 2019 09:47:34 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org Subject: [PATCH v3] tools/lib/traceevent, perf tools: Handle %pU format correctly Date: Mon, 21 Oct 2019 17:47:30 +0800 Message-Id: <20191021094730.57332-1-wqu@suse.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org [BUG] For btrfs related events, there is a field for fsid, but perf never parse it correctly. # perf trace -e btrfs:qgroup_meta_convert xfs_io -f -c "pwrite 0 4k" \ /mnt/btrfs/file1 0.000 xfs_io/77915 btrfs:qgroup_meta_reserve:(nil)U: refroot=5(FS_TREE) type=0x0 diff=2 ^^^^^^ Not a correct UUID ... [CAUSE] The pretty_print() function doesn't handle the %pU format correctly. In fact it doesn't handle %pU as uuid at all. [FIX] Add a new function, print_uuid_arg(), to handle %pU correctly. Now perf trace can at least print fsid correctly: 0.000 xfs_io/79619 btrfs:qgroup_meta_reserve:23ad1511-dd83-47d4-a79c-e96625a15a6e refroot=5(FS_TREE) type=0x0 diff=2 Signed-off-by: Qu Wenruo --- Changelog: v2: - Use more comment explaining the finetunings we skipped for %pU* - Extra check for the field before reading the data - Use more elegant way to output uuid string v3: - Use a even more elegant way to output uuid string --- tools/lib/traceevent/event-parse.c | 51 ++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index d948475585ce..a71f4a86b6ca 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -4508,6 +4509,40 @@ get_bprint_format(void *data, int size __maybe_unused, return format; } +static void print_uuid_arg(struct trace_seq *s, void *data, int size, + struct tep_event *event, struct tep_print_arg *arg) +{ + unsigned char *buf; + int i; + + if (arg->type != TEP_PRINT_FIELD) { + trace_seq_printf(s, "ARG TYPE NOT FIELID but %d", arg->type); + return; + } + + if (!arg->field.field) { + arg->field.field = tep_find_any_field(event, arg->field.name); + if (!arg->field.field) { + do_warning("%s: field %s not found", + __func__, arg->field.name); + return; + } + } + if (arg->field.field->size < 16) { + trace_seq_printf(s, "INVALID UUID: size have %u expect 16", + arg->field.field->size); + return; + } + buf = data + arg->field.field->offset; + + for (i = 0; i < 8; i++) { + trace_seq_printf(s, "%02x", buf[2 * i]); + trace_seq_printf(s, "%02x", buf[2 * i + 1]); + if (1 <= i && i <= 4) + trace_seq_putc(s, '-'); + } +} + static void print_mac_arg(struct trace_seq *s, int mac, void *data, int size, struct tep_event *event, struct tep_print_arg *arg) { @@ -5074,6 +5109,22 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct tep_e arg = arg->next; break; } + } else if (*ptr == 'U') { + /* + * %pU has several finetunings variants + * like %pUb and %pUL. + * Here we ignore them, default to + * byte-order no endian, lower case + * letters. + */ + if (isalpha(ptr[1])) + ptr += 2; + else + ptr++; + + print_uuid_arg(s, data, size, event, arg); + arg = arg->next; + break; } /* fall through */