#include <linux/syscalls.h>
#include <linux/kexec.h>
#include <linux/ratelimit.h>
+#include <linux/kmsg_dump.h>
+#include <linux/syslog.h>
#include <asm/uaccess.h>
DEFAULT_CONSOLE_LOGLEVEL, /* default_console_loglevel */
};
-static int saved_console_loglevel = -1;
-
/*
* Low level drivers may need that to know if they can schedule in
* their unblank() callback or not. So let's export it.
static char *log_buf = __log_buf;
static int log_buf_len = __LOG_BUF_LEN;
static unsigned logged_chars; /* Number of chars produced since last read+clear operation */
+static int saved_console_loglevel = -1;
#ifdef CONFIG_KEXEC
/*
}
#endif
-/*
- * Commands to do_syslog:
- *
- * 0 -- Close the log. Currently a NOP.
- * 1 -- Open the log. Currently a NOP.
- * 2 -- Read from the log.
- * 3 -- Read all messages remaining in the ring buffer.
- * 4 -- Read and clear all messages remaining in the ring buffer
- * 5 -- Clear ring buffer.
- * 6 -- Disable printk's to console
- * 7 -- Enable printk's to console
- * 8 -- Set level of messages printed to console
- * 9 -- Return number of unread characters in the log buffer
- * 10 -- Return size of the log buffer
- */
-int do_syslog(int type, char __user *buf, int len)
+int do_syslog(int type, char __user *buf, int len, bool from_file)
{
unsigned i, j, limit, count;
int do_clear = 0;
char c;
int error = 0;
- error = security_syslog(type);
+ error = security_syslog(type, from_file);
if (error)
return error;
switch (type) {
- case 0: /* Close log */
+ case SYSLOG_ACTION_CLOSE: /* Close log */
break;
- case 1: /* Open log */
+ case SYSLOG_ACTION_OPEN: /* Open log */
break;
- case 2: /* Read from log */
+ case SYSLOG_ACTION_READ: /* Read from log */
error = -EINVAL;
if (!buf || len < 0)
goto out;
if (!error)
error = i;
break;
- case 4: /* Read/clear last kernel messages */
+ /* Read/clear last kernel messages */
+ case SYSLOG_ACTION_READ_CLEAR:
do_clear = 1;
/* FALL THRU */
- case 3: /* Read last kernel messages */
+ /* Read last kernel messages */
+ case SYSLOG_ACTION_READ_ALL:
error = -EINVAL;
if (!buf || len < 0)
goto out;
}
}
break;
- case 5: /* Clear ring buffer */
+ /* Clear ring buffer */
+ case SYSLOG_ACTION_CLEAR:
logged_chars = 0;
break;
- case 6: /* Disable logging to console */
+ /* Disable logging to console */
+ case SYSLOG_ACTION_CONSOLE_OFF:
if (saved_console_loglevel == -1)
saved_console_loglevel = console_loglevel;
console_loglevel = minimum_console_loglevel;
break;
- case 7: /* Enable logging to console */
+ /* Enable logging to console */
+ case SYSLOG_ACTION_CONSOLE_ON:
if (saved_console_loglevel != -1) {
console_loglevel = saved_console_loglevel;
saved_console_loglevel = -1;
}
break;
- case 8: /* Set level of messages printed to console */
+ /* Set level of messages printed to console */
+ case SYSLOG_ACTION_CONSOLE_LEVEL:
error = -EINVAL;
if (len < 1 || len > 8)
goto out;
saved_console_loglevel = -1;
error = 0;
break;
- case 9: /* Number of chars in the log buffer */
+ /* Number of chars in the log buffer */
+ case SYSLOG_ACTION_SIZE_UNREAD:
error = log_end - log_start;
break;
- case 10: /* Size of the log buffer */
+ /* Size of the log buffer */
+ case SYSLOG_ACTION_SIZE_BUFFER:
error = log_buf_len;
break;
default:
SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
{
- return do_syslog(type, buf, len);
+ return do_syslog(type, buf, len, SYSLOG_FROM_CALL);
}
/*
return false;
}
EXPORT_SYMBOL(printk_timed_ratelimit);
+
+static DEFINE_SPINLOCK(dump_list_lock);
+static LIST_HEAD(dump_list);
+
+/**
+ * kmsg_dump_register - register a kernel log dumper.
+ * @dumper: pointer to the kmsg_dumper structure
+ *
+ * Adds a kernel log dumper to the system. The dump callback in the
+ * structure will be called when the kernel oopses or panics and must be
+ * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise.
+ */
+int kmsg_dump_register(struct kmsg_dumper *dumper)
+{
+ unsigned long flags;
+ int err = -EBUSY;
+
+ /* The dump callback needs to be set */
+ if (!dumper->dump)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dump_list_lock, flags);
+ /* Don't allow registering multiple times */
+ if (!dumper->registered) {
+ dumper->registered = 1;
+ list_add_tail(&dumper->list, &dump_list);
+ err = 0;
+ }
+ spin_unlock_irqrestore(&dump_list_lock, flags);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_register);
+
+/**
+ * kmsg_dump_unregister - unregister a kmsg dumper.
+ * @dumper: pointer to the kmsg_dumper structure
+ *
+ * Removes a dump device from the system. Returns zero on success and
+ * %-EINVAL otherwise.
+ */
+int kmsg_dump_unregister(struct kmsg_dumper *dumper)
+{
+ unsigned long flags;
+ int err = -EINVAL;
+
+ spin_lock_irqsave(&dump_list_lock, flags);
+ if (dumper->registered) {
+ dumper->registered = 0;
+ list_del(&dumper->list);
+ err = 0;
+ }
+ spin_unlock_irqrestore(&dump_list_lock, flags);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
+
+static const char const *kmsg_reasons[] = {
+ [KMSG_DUMP_OOPS] = "oops",
+ [KMSG_DUMP_PANIC] = "panic",
+ [KMSG_DUMP_KEXEC] = "kexec",
+};
+
+static const char *kmsg_to_str(enum kmsg_dump_reason reason)
+{
+ if (reason >= ARRAY_SIZE(kmsg_reasons) || reason < 0)
+ return "unknown";
+
+ return kmsg_reasons[reason];
+}
+
+/**
+ * kmsg_dump - dump kernel log to kernel message dumpers.
+ * @reason: the reason (oops, panic etc) for dumping
+ *
+ * Iterate through each of the dump devices and call the oops/panic
+ * callbacks with the log buffer.
+ */
+void kmsg_dump(enum kmsg_dump_reason reason)
+{
+ unsigned long end;
+ unsigned chars;
+ struct kmsg_dumper *dumper;
+ const char *s1, *s2;
+ unsigned long l1, l2;
+ unsigned long flags;
+
+ /* Theoretically, the log could move on after we do this, but
+ there's not a lot we can do about that. The new messages
+ will overwrite the start of what we dump. */
+ spin_lock_irqsave(&logbuf_lock, flags);
+ end = log_end & LOG_BUF_MASK;
+ chars = logged_chars;
+ spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ if (logged_chars > end) {
+ s1 = log_buf + log_buf_len - logged_chars + end;
+ l1 = logged_chars - end;
+
+ s2 = log_buf;
+ l2 = end;
+ } else {
+ s1 = "";
+ l1 = 0;
+
+ s2 = log_buf + end - logged_chars;
+ l2 = logged_chars;
+ }
+
+ if (!spin_trylock_irqsave(&dump_list_lock, flags)) {
+ printk(KERN_ERR "dump_kmsg: dump list lock is held during %s, skipping dump\n",
+ kmsg_to_str(reason));
+ return;
+ }
+ list_for_each_entry(dumper, &dump_list, list)
+ dumper->dump(dumper, reason, s1, l1, s2, l2);
+ spin_unlock_irqrestore(&dump_list_lock, flags);
+}
#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff