Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752002AbYKFTBx (ORCPT ); Thu, 6 Nov 2008 14:01:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751103AbYKFTBp (ORCPT ); Thu, 6 Nov 2008 14:01:45 -0500 Received: from smtp-out.google.com ([216.239.45.13]:50967 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096AbYKFTBo (ORCPT ); Thu, 6 Nov 2008 14:01:44 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:date:message-id:subject:from:to:cc: content-type:content-transfer-encoding; b=cPRaRITTEpk8C26E3JeXZ4cHTAVKlSDCo/hd1lviX+0CFXqGP5oq8HMhQmtNxMvcT HSA3yhbpKDdc3Nxp9S88A== MIME-Version: 1.0 Date: Thu, 6 Nov 2008 11:01:39 -0800 Message-ID: Subject: [patch] add /proc/pid/stack to dump task's stack trace From: Ken Chen To: Ingo Molnar Cc: Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2462 Lines: 78 This patch adds the ability to query a task's stack trace via /proc/pid/stack. It is considered to be more useful than /proc/pid/wchan as it provides full stack trace instead of single depth. Signed-off-by: Ken Chen index bcceb99..3202d5c 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -139,6 +139,7 @@ Table 1-1: Process specific entries in /proc statm Process memory status information status Process status in human readable form wchan If CONFIG_KALLSYMS is set, a pre-decoded wchan + stack If CONFIG_KALLSYMS is set, report full stack trace smaps Extension based on maps, the rss size for each mapped file .............................................................................. diff --git a/fs/proc/base.c b/fs/proc/base.c index 486cf3f..466e519 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -65,6 +65,7 @@ #include #include #include +#include #include #include #include @@ -338,6 +339,35 @@ static int proc_pid_wchan else return sprintf(buffer, "%s", symname); } + +#define MAX_STACK_TRACE_DEPTH 32 +static int proc_stack_trace(struct task_struct *task, char *buffer) +{ + int i, len = 0; + unsigned long *entries; + struct stack_trace trace; + + entries = kmalloc(sizeof(*entries) * MAX_STACK_TRACE_DEPTH, GFP_KERNEL); + if (!entries) + goto out; + + trace.nr_entries = 0; + trace.max_entries = MAX_STACK_TRACE_DEPTH; + trace.entries = entries; + trace.skip = 0; + + read_lock(&tasklist_lock); + save_stack_trace_tsk(task, &trace); + read_unlock(&tasklist_lock); + + for (i = 0; i < trace.nr_entries; i++) { + len += sprintf(buffer + len, "[<%p>] %pS\n", + (void *) entries[i], (void *) entries[i]); + } + kfree(entries); +out: + return len; +} #endif /* CONFIG_KALLSYMS */ #ifdef CONFIG_SCHEDSTATS @@ -2489,6 +2519,7 @@ static const struct pid_entry tgid_base_stuff[] = { DIR("attr", S_IRUGO|S_IXUGO, attr_dir), #endif #ifdef CONFIG_KALLSYMS + INF("stack", S_IRUSR, stack_trace), INF("wchan", S_IRUGO, pid_wchan), #endif #ifdef CONFIG_SCHEDSTATS -- 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/