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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 4441EC43612 for ; Sat, 22 Dec 2018 16:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16CDF2197D for ; Sat, 22 Dec 2018 16:47:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388137AbeLVQra (ORCPT ); Sat, 22 Dec 2018 11:47:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:36914 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725880AbeLVQrO (ORCPT ); Sat, 22 Dec 2018 11:47:14 -0500 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (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 2E90421D53; Sat, 22 Dec 2018 16:28:58 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.91) (envelope-from ) id 1gak93-0001Gs-7N; Sat, 22 Dec 2018 11:28:57 -0500 Message-Id: <20181222162857.116914355@goodmis.org> User-Agent: quilt/0.65 Date: Sat, 22 Dec 2018 11:20:12 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Joe Perches , Namhyung Kim , Linus Torvalds , Yoshinori Sato , Rich Felker , linux-sh@vger.kernel.org, Masami Hiramatsu Subject: [for-next][PATCH 5/5] tracing: Use the return of str_has_prefix() to remove open coded numbers References: <20181222162007.697862256@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" There are several locations that compare constants to the beginning of string variables to determine what commands should be done, then the constant length is used to index into the string. This is error prone as the hard coded numbers have to match the size of the constants. Instead, use the len returned from str_has_prefix() and remove the open coded string length sizes. Cc: Joe Perches Cc: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 8 +++++--- kernel/trace/trace_probe.c | 17 +++++++++-------- kernel/trace/trace_stack.c | 6 ++++-- 3 files changed, 18 insertions(+), 13 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index eac2824a18ab..18b86c3974e1 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4408,13 +4408,15 @@ static int trace_set_options(struct trace_array *tr, char *option) int neg = 0; int ret; size_t orig_len = strlen(option); + int len; cmp = strstrip(option); - if (str_has_prefix(cmp, "no")) { + len = str_has_prefix(cmp, "no"); + if (len) neg = 1; - cmp += 2; - } + + cmp += len; mutex_lock(&trace_types_lock); diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 541375737403..9962cb5da8ac 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -186,19 +186,20 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, static int parse_probe_vars(char *arg, const struct fetch_type *t, struct fetch_insn *code, unsigned int flags) { - int ret = 0; unsigned long param; + int ret = 0; + int len; if (strcmp(arg, "retval") == 0) { if (flags & TPARG_FL_RETURN) code->op = FETCH_OP_RETVAL; else ret = -EINVAL; - } else if (str_has_prefix(arg, "stack")) { - if (arg[5] == '\0') { + } else if ((len = str_has_prefix(arg, "stack"))) { + if (arg[len] == '\0') { code->op = FETCH_OP_STACKP; - } else if (isdigit(arg[5])) { - ret = kstrtoul(arg + 5, 10, ¶m); + } else if (isdigit(arg[len])) { + ret = kstrtoul(arg + len, 10, ¶m); if (ret || ((flags & TPARG_FL_KERNEL) && param > PARAM_MAX_STACK)) ret = -EINVAL; @@ -213,10 +214,10 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API } else if (((flags & TPARG_FL_MASK) == (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) && - str_has_prefix(arg, "arg")) { - if (!isdigit(arg[3])) + (len = str_has_prefix(arg, "arg"))) { + if (!isdigit(arg[len])) return -EINVAL; - ret = kstrtoul(arg + 3, 10, ¶m); + ret = kstrtoul(arg + len, 10, ¶m); if (ret || !param || param > PARAM_MAX_STACK) return -EINVAL; code->op = FETCH_OP_ARG; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 3641f28c343f..eec648a0d673 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -448,8 +448,10 @@ static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata; static __init int enable_stacktrace(char *str) { - if (str_has_prefix(str, "_filter=")) - strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE); + int len; + + if ((len = str_has_prefix(str, "_filter="))) + strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); stack_tracer_enabled = 1; last_stack_tracer_enabled = 1; -- 2.19.2