pstore: Add console log messages support
Pstore doesn't support logging kernel messages in run-time, it only
dumps dmesg when kernel oopses/panics. This makes pstore useless for
debugging hangs caused by HW issues or improper use of HW (e.g.
weird device inserted -> driver tried to write a reserved bits ->
SoC hanged. In that case we don't get any messages in the pstore.
Therefore, let's add a runtime logging support: PSTORE_TYPE_CONSOLE.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 82c585f..61461ed 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -1,6 +1,7 @@
/*
* Persistent Storage - platform driver interface parts.
*
+ * Copyright (C) 2007-2008 Google, Inc.
* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
*
* This program is free software; you can redistribute it and/or modify
@@ -22,6 +23,7 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kmsg_dump.h>
+#include <linux/console.h>
#include <linux/module.h>
#include <linux/pstore.h>
#include <linux/string.h>
@@ -156,6 +158,40 @@
.dump = pstore_dump,
};
+#ifdef CONFIG_PSTORE_CONSOLE
+static void pstore_console_write(struct console *con, const char *s, unsigned c)
+{
+ const char *e = s + c;
+
+ while (s < e) {
+ unsigned long flags;
+
+ if (c > psinfo->bufsize)
+ c = psinfo->bufsize;
+ spin_lock_irqsave(&psinfo->buf_lock, flags);
+ memcpy(psinfo->buf, s, c);
+ psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo);
+ spin_unlock_irqrestore(&psinfo->buf_lock, flags);
+ s += c;
+ c = e - s;
+ }
+}
+
+static struct console pstore_console = {
+ .name = "pstore",
+ .write = pstore_console_write,
+ .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
+ .index = -1,
+};
+
+static void pstore_register_console(void)
+{
+ register_console(&pstore_console);
+}
+#else
+static void pstore_register_console(void) {}
+#endif
+
/*
* platform specific persistent storage driver registers with
* us here. If pstore is already mounted, call the platform
@@ -193,6 +229,7 @@
pstore_get_records(0);
kmsg_dump_register(&pstore_dumper);
+ pstore_register_console();
pstore_timer.expires = jiffies + PSTORE_INTERVAL;
add_timer(&pstore_timer);