From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0340EC433FF for ; Tue, 30 Jul 2019 02:57:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C02A2216C8 for ; Tue, 30 Jul 2019 02:57:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564455459; bh=NhXQarjctVferxtZwkYTQOXsbKNlEMmpQOdze78Ejts=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZszZ027+vl/GLeMZUExmqEEvR7L2OaBZKvmMAP+O5gvEdqpIvEc0yd1FATOVgaoLc p1KdWFtomdZ3EJK3bmDpl+nHTacBAEIocjGtG1BZZU/dP3gYukXwd7jCVQQFq7jLUm rWNXXZZ+HAZPCYBb08MmP9p2M58kUFNI5JPyiuBY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731832AbfG3C5i (ORCPT ); Mon, 29 Jul 2019 22:57:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:47104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731787AbfG3C5g (ORCPT ); Mon, 29 Jul 2019 22:57:36 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.35.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0D740206DD; Tue, 30 Jul 2019 02:57:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564455455; bh=NhXQarjctVferxtZwkYTQOXsbKNlEMmpQOdze78Ejts=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NUGhFy3GX+D71uc24k34Va+BL6lHY/ALAACJZ7nQTxMx0mre4/Zg6l0DVTv4RcG8H PAaPep/4WXFUziQNwoXbue+grtYqCMe+i/sAgnJ75eurG0gNSydIG5Ef4RmbO9deeZ BGbxNaTYvtsXqcw96IU4IKraIXGPsi2g2dRsOh/s= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Brendan Gregg , =?UTF-8?q?Luis=20Cl=C3=A1udio=20Gon=C3=A7alves?= Subject: [PATCH 025/107] perf trace: Preallocate the syscall table Date: Mon, 29 Jul 2019 23:54:48 -0300 Message-Id: <20190730025610.22603-26-acme@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190730025610.22603-1-acme@kernel.org> References: <20190730025610.22603-1-acme@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo We'll continue reading its details from tracefs as we need it, but preallocate the whole thing otherwise we may realloc and end up with pointers to the previous buffer. I.e. in an upcoming algorithm we'll look for syscalls that have function signatures that are similar to a given syscall to see if we can reuse its BPF augmenter, so we may be at syscall 42, having a 'struct syscall' pointing to that slot in trace->syscalls.table[] and try to read the slot for an yet unread syscall, which would realloc that table to read the info for syscall 43, say, which would trigger a realoc of trace->syscalls.table[], and then the pointer we had for syscall 42 would be pointing to the previous block of memory. b00m. Cc: Adrian Hunter Cc: Brendan Gregg Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-m3cjzzifibs13imafhkk77a0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 29 +++++++---------------------- tools/perf/util/syscalltbl.c | 1 + tools/perf/util/syscalltbl.h | 1 + 3 files changed, 9 insertions(+), 22 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 765b998755ce..d8565c9a18a2 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -79,7 +79,6 @@ struct trace { struct perf_tool tool; struct syscalltbl *sctbl; struct { - int max; struct syscall *table; struct bpf_map *map; struct { // per syscall BPF_MAP_TYPE_PROG_ARRAY @@ -1493,21 +1492,10 @@ static int trace__read_syscall_info(struct trace *trace, int id) struct syscall *sc; const char *name = syscalltbl__name(trace->sctbl, id); - if (id > trace->syscalls.max) { - struct syscall *nsyscalls = realloc(trace->syscalls.table, (id + 1) * sizeof(*sc)); - - if (nsyscalls == NULL) + if (trace->syscalls.table == NULL) { + trace->syscalls.table = calloc(trace->sctbl->syscalls.nr_entries, sizeof(*sc)); + if (trace->syscalls.table == NULL) return -ENOMEM; - - if (trace->syscalls.max != -1) { - memset(nsyscalls + trace->syscalls.max + 1, 0, - (id - trace->syscalls.max) * sizeof(*sc)); - } else { - memset(nsyscalls, 0, (id + 1) * sizeof(*sc)); - } - - trace->syscalls.table = nsyscalls; - trace->syscalls.max = id; } sc = trace->syscalls.table + id; @@ -1819,11 +1807,11 @@ static struct syscall *trace__syscall_info(struct trace *trace, err = -EINVAL; - if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL) && - (err = trace__read_syscall_info(trace, id)) != 0) + if (id > trace->sctbl->syscalls.max_id) goto out_cant_read; - if (id > trace->syscalls.max) + if ((trace->syscalls.table == NULL || trace->syscalls.table[id].name == NULL) && + (err = trace__read_syscall_info(trace, id)) != 0) goto out_cant_read; if (trace->syscalls.table[id].name == NULL) { @@ -1838,7 +1826,7 @@ static struct syscall *trace__syscall_info(struct trace *trace, if (verbose > 0) { char sbuf[STRERR_BUFSIZE]; fprintf(trace->output, "Problems reading syscall %d: %d (%s)", id, -err, str_error_r(-err, sbuf, sizeof(sbuf))); - if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL) + if (id <= trace->sctbl->syscalls.max_id && trace->syscalls.table[id].name != NULL) fprintf(trace->output, "(%s)", trace->syscalls.table[id].name); fputs(" information\n", trace->output); } @@ -3922,9 +3910,6 @@ int cmd_trace(int argc, const char **argv) NULL }; struct trace trace = { - .syscalls = { - . max = -1, - }, .opts = { .target = { .uid = UINT_MAX, diff --git a/tools/perf/util/syscalltbl.c b/tools/perf/util/syscalltbl.c index 022a9c670338..820fceeb19a9 100644 --- a/tools/perf/util/syscalltbl.c +++ b/tools/perf/util/syscalltbl.c @@ -79,6 +79,7 @@ static int syscalltbl__init_native(struct syscalltbl *tbl) qsort(tbl->syscalls.entries, nr_entries, sizeof(struct syscall), syscallcmp); tbl->syscalls.nr_entries = nr_entries; + tbl->syscalls.max_id = syscalltbl_native_max_id; return 0; } diff --git a/tools/perf/util/syscalltbl.h b/tools/perf/util/syscalltbl.h index c8e7e9ce0f01..9172613028d0 100644 --- a/tools/perf/util/syscalltbl.h +++ b/tools/perf/util/syscalltbl.h @@ -6,6 +6,7 @@ struct syscalltbl { union { int audit_machine; struct { + int max_id; int nr_entries; void *entries; } syscalls; -- 2.21.0