Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 22 Oct 2002 01:45:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 22 Oct 2002 01:45:40 -0400 Received: from svr-ganmtc-appserv-mgmt.ncf.coxexpress.com ([24.136.46.5]:58634 "EHLO svr-ganmtc-appserv-mgmt.ncf.coxexpress.com") by vger.kernel.org with ESMTP id ; Tue, 22 Oct 2002 01:45:38 -0400 Subject: [patch] 2.5: pre-decoded wchan output From: Robert Love To: linux-kernel@vger.kernel.org Cc: hch@infradead.org, akpm@digeo.com Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 (1.0.8-10) Date: 22 Oct 2002 01:52:03 -0400 Message-Id: <1035265924.1044.92.camel@phantasy> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4070 Lines: 122 Attached patch implements a /proc/#/wchan which provides a pre-decoded wchan via kallsyms. I.e., [01:47:26]rml@phantasy:~$ cat /proc/712/wchan wait4 Which is damn nifty and will let ps(1) grab wchan information without having to parse System.map - in fact, procps will no longer need System.map at all. If CONFIG_KALLSYMS is enabled, /proc/#/wchan exists and exports the pre-decoded symbol name. If it does not exist, neither does the file. The old interface in /proc/#/stat exists either way, per a suggestion from Christoph. I am not sure I agree (I would like to avoid the get_wchan() in stat if CONFIG_KALLSYMS is set) but for now I agree this is less invasive. The procps patch is available at: http://tech9.net/rml/procps/patches/procps-wchan-rml-2.0.10.20021011-1.patch and ready for merging into procps CVS. Patch is against 2.5.44. Whoever is one of the secret, mysterious, incredibly handsome freeze integrators, please apply. :) Robert Love Documentation/filesystems/proc.txt | 1 + fs/proc/base.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff -urN linux-2.5.44/Documentation/filesystems/proc.txt linux/Documentation/filesystems/proc.txt --- linux-2.5.44/Documentation/filesystems/proc.txt 2002-10-19 00:01:19.000000000 -0400 +++ linux/Documentation/filesystems/proc.txt 2002-10-22 01:39:33.000000000 -0400 @@ -130,6 +130,7 @@ stat Process status statm Process memory status information status Process status in human readable form + wchan If CONFIG_KALLSYMS is set, a pre-decoded wchan .............................................................................. For example, to get the status information of a process, all you have to do is diff -urN linux-2.5.44/fs/proc/base.c linux/fs/proc/base.c --- linux-2.5.44/fs/proc/base.c 2002-10-19 00:02:00.000000000 -0400 +++ linux/fs/proc/base.c 2002-10-22 01:39:33.000000000 -0400 @@ -28,6 +28,7 @@ #include #include #include +#include /* * For hysterical raisins we keep the same inumbers as in the old procfs. @@ -54,6 +55,7 @@ PROC_PID_MAPS, PROC_PID_CPU, PROC_PID_MOUNTS, + PROC_PID_WCHAN, PROC_PID_FD_DIR = 0x8000, /* 0x8000-0xffff */ }; @@ -81,6 +83,9 @@ E(PROC_PID_ROOT, "root", S_IFLNK|S_IRWXUGO), E(PROC_PID_EXE, "exe", S_IFLNK|S_IRWXUGO), E(PROC_PID_MOUNTS, "mounts", S_IFREG|S_IRUGO), +#ifdef CONFIG_KALLSYMS + E(PROC_PID_WCHAN, "wchan", S_IFREG|S_IRUGO), +#endif {0,0,NULL,0} }; #undef E @@ -245,6 +250,28 @@ return res; } +#ifdef CONFIG_KALLSYMS +/* + * Provides a wchan file via kallsyms in a proper one-value-per-file format. + * Returns the resolved symbol. If that fails, simply return the address. + */ +static int proc_pid_wchan(struct task_struct *task, char *buffer) +{ + const char *sym_name, *ignore; + unsigned long wchan, dummy; + + wchan = get_wchan(task); + + if (!kallsyms_address_to_symbol(wchan, &ignore, &dummy, &dummy, + &ignore, &dummy, &dummy, &sym_name, + &dummy, &dummy)) { + return sprintf(buffer, "%lu", wchan); + } + + return sprintf(buffer, "%s", sym_name); +} +#endif + /************************************************************************/ /* Here the fs part begins */ /************************************************************************/ @@ -1016,6 +1043,12 @@ case PROC_PID_MOUNTS: inode->i_fop = &proc_mounts_operations; break; +#ifdef CONFIG_KALLSYMS + case PROC_PID_WCHAN: + inode->i_fop = &proc_info_file_operations; + ei->op.proc_read = proc_pid_wchan; + break; +#endif default: printk("procfs: impossible type (%d)",p->type); iput(inode); - 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/