---

yaml
---
r: 198799
b: refs/heads/master
c: 56d611a
h: refs/heads/master
i:
  198797: a70bef1
  198795: 2960de3
  198791: 7afff66
  198783: 33c2bbb
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a747c5abc329611220f16df0bb4cf0ca4a7fdf0c
+refs/heads/master: 56d611a04fb2db77334e06274de4daed92e2c626

trunk/drivers/char/Kconfig

@@ -1121,5 +1121,12 @@ config DEVPORT
 
 source "drivers/s390/char/Kconfig"
 
+config RAMOOPS
+	tristate "Log panic/oops to a RAM buffer"
+	default n
+	help
+	  This enables panic and oops messages to be logged to a circular
+	  buffer in RAM where it can be read back at some later point.
+
 endmenu
 

trunk/drivers/char/Makefile

@@ -108,6 +108,7 @@ obj-$(CONFIG_HANGCHECK_TIMER)	+= hangcheck-timer.o
 obj-$(CONFIG_TCG_TPM)		+= tpm/
 
 obj-$(CONFIG_PS3_FLASH)		+= ps3flash.o
+obj-$(CONFIG_RAMOOPS)		+= ramoops.o
 
 obj-$(CONFIG_JS_RTC)		+= js-rtc.o
 js-rtc-y = rtc.o

trunk/drivers/char/ramoops.c

@@ -0,0 +1,162 @@
+/*
+ * RAM Oops/Panic logger
+ *
+ * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kmsg_dump.h>
+#include <linux/time.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+
+#define RAMOOPS_KERNMSG_HDR "===="
+#define RAMOOPS_HEADER_SIZE   (5 + sizeof(struct timeval))
+
+#define RECORD_SIZE 4096
+
+static ulong mem_address;
+module_param(mem_address, ulong, 0400);
+MODULE_PARM_DESC(mem_address,
+		"start of reserved RAM used to store oops/panic logs");
+
+static ulong mem_size;
+module_param(mem_size, ulong, 0400);
+MODULE_PARM_DESC(mem_size,
+		"size of reserved RAM used to store oops/panic logs");
+
+static int dump_oops = 1;
+module_param(dump_oops, int, 0600);
+MODULE_PARM_DESC(dump_oops,
+		"set to 1 to dump oopses, 0 to only dump panics (default 1)");
+
+static struct ramoops_context {
+	struct kmsg_dumper dump;
+	void *virt_addr;
+	phys_addr_t phys_addr;
+	unsigned long size;
+	int count;
+	int max_count;
+} oops_cxt;
+
+static void ramoops_do_dump(struct kmsg_dumper *dumper,
+		enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
+		const char *s2, unsigned long l2)
+{
+	struct ramoops_context *cxt = container_of(dumper,
+			struct ramoops_context, dump);
+	unsigned long s1_start, s2_start;
+	unsigned long l1_cpy, l2_cpy;
+	int res;
+	char *buf;
+	struct timeval timestamp;
+
+	/* Only dump oopses if dump_oops is set */
+	if (reason == KMSG_DUMP_OOPS && !dump_oops)
+		return;
+
+	buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE));
+	memset(buf, '\0', RECORD_SIZE);
+	res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
+	buf += res;
+	do_gettimeofday(&timestamp);
+	res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
+	buf += res;
+
+	l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE));
+	l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy);
+
+	s2_start = l2 - l2_cpy;
+	s1_start = l1 - l1_cpy;
+
+	memcpy(buf, s1 + s1_start, l1_cpy);
+	memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
+
+	cxt->count = (cxt->count + 1) % cxt->max_count;
+}
+
+static int __init ramoops_init(void)
+{
+	struct ramoops_context *cxt = &oops_cxt;
+	int err = -EINVAL;
+
+	if (!mem_size) {
+		printk(KERN_ERR "ramoops: invalid size specification");
+		goto fail3;
+	}
+
+	rounddown_pow_of_two(mem_size);
+
+	if (mem_size < RECORD_SIZE) {
+		printk(KERN_ERR "ramoops: size too small");
+		goto fail3;
+	}
+
+	cxt->max_count = mem_size / RECORD_SIZE;
+	cxt->count = 0;
+	cxt->size = mem_size;
+	cxt->phys_addr = mem_address;
+
+	if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
+		printk(KERN_ERR "ramoops: request mem region failed");
+		err = -EINVAL;
+		goto fail3;
+	}
+
+	cxt->virt_addr = ioremap(cxt->phys_addr,  cxt->size);
+	if (!cxt->virt_addr) {
+		printk(KERN_ERR "ramoops: ioremap failed");
+		goto fail2;
+	}
+
+	cxt->dump.dump = ramoops_do_dump;
+	err = kmsg_dump_register(&cxt->dump);
+	if (err) {
+		printk(KERN_ERR "ramoops: registering kmsg dumper failed");
+		goto fail1;
+	}
+
+	return 0;
+
+fail1:
+	iounmap(cxt->virt_addr);
+fail2:
+	release_mem_region(cxt->phys_addr, cxt->size);
+fail3:
+	return err;
+}
+
+static void __exit ramoops_exit(void)
+{
+	struct ramoops_context *cxt = &oops_cxt;
+
+	if (kmsg_dump_unregister(&cxt->dump) < 0)
+		printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
+
+	iounmap(cxt->virt_addr);
+	release_mem_region(cxt->phys_addr, cxt->size);
+}
+
+
+module_init(ramoops_init);
+module_exit(ramoops_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
+MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");