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-rw-r--r--drivers/char/ramoops.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c
new file mode 100644
index 0000000..74f00b5
--- /dev/null
+++ b/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");
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