Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754584AbZKUNe4 (ORCPT ); Sat, 21 Nov 2009 08:34:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754457AbZKUNez (ORCPT ); Sat, 21 Nov 2009 08:34:55 -0500 Received: from hera.kernel.org ([140.211.167.34]:41588 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753870AbZKUNew (ORCPT ); Sat, 21 Nov 2009 08:34:52 -0500 Date: Sat, 21 Nov 2009 13:34:07 GMT From: tip-bot for Li Zefan Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, stern@rowland.harvard.edu, lizf@cn.fujitsu.com, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu, prasad@linux.vnet.ibm.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, stern@rowland.harvard.edu, lizf@cn.fujitsu.com, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu, prasad@linux.vnet.ibm.com In-Reply-To: <4A52E2B4.6030706@cn.fujitsu.com> References: <4A52E2B4.6030706@cn.fujitsu.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] ksym_tracer: Rewrite ksym_trace_filter_read() Message-ID: Git-Commit-ID: be9742e6cb107fe1d77db7a081ea4eb25e79e1ad X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2929 Lines: 87 Commit-ID: be9742e6cb107fe1d77db7a081ea4eb25e79e1ad Gitweb: http://git.kernel.org/tip/be9742e6cb107fe1d77db7a081ea4eb25e79e1ad Author: Li Zefan AuthorDate: Tue, 7 Jul 2009 13:52:52 +0800 Committer: Ingo Molnar CommitDate: Fri, 10 Jul 2009 11:59:40 +0200 ksym_tracer: Rewrite ksym_trace_filter_read() Reading ksym_trace_filter gave me some arbitrary characters, when it should show nothing. It's because buf is not initialized when there's no filter. Also reduce stack usage by about 512 bytes. Signed-off-by: Li Zefan Acked-by: Frederic Weisbecker Cc: "K.Prasad" Cc: Alan Stern Cc: Steven Rostedt LKML-Reference: <4A52E2B4.6030706@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_ksym.c | 29 ++++++++++++++++++----------- 1 files changed, 18 insertions(+), 11 deletions(-) diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index 085ff05..b6710d3 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -35,7 +35,6 @@ #define KSYM_TRACER_MAX HBP_NUM #define KSYM_TRACER_OP_LEN 3 /* rw- */ -#define KSYM_FILTER_ENTRY_LEN (KSYM_NAME_LEN + KSYM_TRACER_OP_LEN + 1) struct trace_ksym { struct hw_breakpoint *ksym_hbp; @@ -230,25 +229,33 @@ static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, { struct trace_ksym *entry; struct hlist_node *node; - char buf[KSYM_FILTER_ENTRY_LEN * KSYM_TRACER_MAX]; - ssize_t ret, cnt = 0; + struct trace_seq *s; + ssize_t cnt = 0; + int ret; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + trace_seq_init(s); mutex_lock(&ksym_tracer_mutex); hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { - cnt += snprintf(&buf[cnt], KSYM_FILTER_ENTRY_LEN - cnt, "%s:", - entry->ksym_hbp->info.name); + ret = trace_seq_printf(s, "%s:", entry->ksym_hbp->info.name); if (entry->ksym_hbp->info.type == HW_BREAKPOINT_WRITE) - cnt += snprintf(&buf[cnt], KSYM_FILTER_ENTRY_LEN - cnt, - "-w-\n"); + ret = trace_seq_puts(s, "-w-\n"); else if (entry->ksym_hbp->info.type == HW_BREAKPOINT_RW) - cnt += snprintf(&buf[cnt], KSYM_FILTER_ENTRY_LEN - cnt, - "rw-\n"); + ret = trace_seq_puts(s, "rw-\n"); + WARN_ON_ONCE(!ret); } - ret = simple_read_from_buffer(ubuf, count, ppos, buf, strlen(buf)); + + cnt = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); + mutex_unlock(&ksym_tracer_mutex); - return ret; + kfree(s); + + return cnt; } static ssize_t ksym_trace_filter_write(struct file *file, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/