Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933578AbZJMNYK (ORCPT ); Tue, 13 Oct 2009 09:24:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759881AbZJMNYK (ORCPT ); Tue, 13 Oct 2009 09:24:10 -0400 Received: from ernst.netinsight.se ([194.16.221.21]:35580 "HELO ernst.netinsight.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1759866AbZJMNYI (ORCPT ); Tue, 13 Oct 2009 09:24:08 -0400 Date: Tue, 13 Oct 2009 15:22:35 +0200 From: Simon Kagstrom To: Linus Torvalds , linux-mtd Cc: Ingo Molnar , Andrew Morton , Artem Bityutskiy , David Woodhouse , LKML , "Koskinen Aaro (Nokia-D/Helsinki)" , Alan Cox Subject: [PATCH/RFC v5 4/5]: core: Add dump device to call on oopses and panics Message-ID: <20091013152235.188059d2@marrow.netinsight.se> In-Reply-To: <20091013151751.59e217a7@marrow.netinsight.se> References: <20091012113758.GB11035@elte.hu> <20091012140149.6789efab@marrow.netinsight.se> <20091012120951.GA16799@elte.hu> <1255349748.10605.13.camel@macbook.infradead.org> <20091012122023.GA19365@elte.hu> <20091012150650.51a4b4dc@marrow.netinsight.se> <20091012131528.GC25464@elte.hu> <20091012153937.0dcd73e5@marrow.netinsight.se> <20091012110954.67d7d8d8.akpm@linux-foundation.org> <20091012182346.GH17138@elte.hu> <20091013151751.59e217a7@marrow.netinsight.se> X-Mailer: Claws Mail 3.7.3 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5227 Lines: 189 The core functionality is implemented as per Linus suggestion from http://lists.infradead.org/pipermail/linux-mtd/2009-October/027620.html a struct dump_device type has been added which contains callbacks to dump the kernel log buffers on crashes. The dump_kmsg function gets called from oops_exit() and panic() and invokes these callbacks. Signed-off-by: Simon Kagstrom --- include/linux/dump_device.h | 33 +++++++++++++++++ kernel/panic.c | 3 ++ kernel/printk.c | 83 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 119 insertions(+), 0 deletions(-) create mode 100644 include/linux/dump_device.h diff --git a/include/linux/dump_device.h b/include/linux/dump_device.h new file mode 100644 index 0000000..8c3f378 --- /dev/null +++ b/include/linux/dump_device.h @@ -0,0 +1,33 @@ +/* + * linux/include/dump_device.h + * + * Copyright (C) 2009 Net Insight + * + * Author: Simon Kagstrom + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ +#ifndef _LINUX_DUMP_DEVICE_H +#define _LINUX_DUMP_DEVICE_H + +#include + +struct dump_device { + void (*oops)(struct dump_device *, const char *, unsigned long, + const char *, unsigned long); + void (*panic)(struct dump_device *, const char *, unsigned long, + const char *, unsigned long); + int (*setup)(struct dump_device *); + void *priv; + struct list_head list; +}; + +void dump_kmsg(int panic); + +int register_dumpdevice(struct dump_device *dump, void *priv); + +void unregister_dumpdevice(struct dump_device *dump); + +#endif /* _LINUX_DUMP_DEVICE_H */ diff --git a/kernel/panic.c b/kernel/panic.c index c0b33b8..e7dbf2b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -8,6 +8,7 @@ * This function is used through-out the kernel (including mm and fs) * to indicate a major problem. */ +#include #include #include #include @@ -76,6 +77,7 @@ NORET_TYPE void panic(const char * fmt, ...) dump_stack(); #endif + dump_kmsg(1); /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. @@ -341,6 +343,7 @@ void oops_exit(void) { do_oops_enter_exit(); print_oops_end_marker(); + dump_kmsg(0); } #ifdef WANT_WARN_ON_SLOWPATH diff --git a/kernel/printk.c b/kernel/printk.c index f38b07f..5e1fe73 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -33,6 +33,7 @@ #include #include #include +#include #include @@ -1405,3 +1406,85 @@ bool printk_timed_ratelimit(unsigned long *caller_jiffies, } EXPORT_SYMBOL(printk_timed_ratelimit); #endif + +static LIST_HEAD(dump_list); +static DEFINE_RWLOCK(dump_list_lock); + +/** + * register_dump_device - register a dumpdevice. + * @dump: pointer to the dump structure + * @priv: private data for the structure + * + * Adds a dump device to the system. The oops and panic callbacks + * in the structure will be called when the kernel oopses and panics + * respectively. At least one of these must be set. Returns zero on + * success and -EINVAL otherwise. + */ +int register_dumpdevice(struct dump_device *dump, void *priv) +{ + /* We need at least one of these set */ + if (!dump->oops && !dump->panic) + return -EINVAL; + if (dump->setup && dump->setup(dump) != 0) + return -EINVAL; + dump->priv = priv; + + INIT_LIST_HEAD(&dump->list); + write_lock(&dump_list_lock); + list_add(&dump->list, &dump_list); + write_unlock(&dump_list_lock); + return 0; +} +EXPORT_SYMBOL(register_dumpdevice); + +/** + * unregister_dump_device - unregister a dumpdevice. + * @dump: pointer to the dump structure + * + * Removes a dump device from the system. + */ +void unregister_dumpdevice(struct dump_device *dump) +{ + write_lock(&dump_list_lock); + list_del(&dump->list); + write_unlock(&dump_list_lock); +} +EXPORT_SYMBOL(unregister_dumpdevice); + +/** + * dump_kmsg - dump kernel log to dump devices. + * @panic: if this is a panic (1) or an oops (0) + * + * Iterate through each of the dump devices and call the oops/panic + * callbacks with the log buffer. + */ +void dump_kmsg(int panic) +{ + unsigned long len = ACCESS_ONCE(log_end); + struct dump_device *dump; + const char *s1, *s2; + unsigned long l1, l2; + + s1 = ""; + l1 = 0; + s2 = log_buf; + l2 = len; + + /* Have we rotated around the circular buffer? */ + if (len > log_buf_len) { + unsigned long pos = (len & LOG_BUF_MASK); + + s1 = log_buf + pos; + l1 = log_buf_len - pos; + + s2 = log_buf; + l2 = pos; + } + + list_for_each_entry(dump, &dump_list, list) { + if (panic && dump->panic) + dump->panic(dump, s1, l1, s2, l2); + else if (!panic && dump->oops) + dump->oops(dump, s1, l1, s2, l2); + } +} -- 1.6.0.4 -- 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/