Commit f29e5956 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by Greg Kroah-Hartman
Browse files

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: default avatarAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarColin Cross <ccross@android.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 89a86a2d

fs/pstore/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -12,6 +12,13 @@ config PSTORE 
	   If you don't have a platform persistent store driver,

	   say N.



config PSTORE_CONSOLE

	bool "Log kernel console messages"

	depends on PSTORE

	help

	  When the option is enabled, pstore will log all kernel

	  messages, even if no oops or panic happened.



config PSTORE_RAM

	tristate "Log panic/oops to a RAM buffer"

	depends on PSTORE

fs/pstore/inode.c

+3 −0
Original line number Diff line number Diff line
@@ -212,6 +212,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, 
	case PSTORE_TYPE_DMESG:

		sprintf(name, "dmesg-%s-%lld", psname, id);

		break;

	case PSTORE_TYPE_CONSOLE:

		sprintf(name, "console-%s", psname);

		break;

	case PSTORE_TYPE_MCE:

		sprintf(name, "mce-%s-%lld", psname, id);

		break;

fs/pstore/platform.c

+37 −0
Original line number Diff line number Diff line 
/*

 * 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 @@ static struct kmsg_dumper pstore_dumper = { 
	.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 @@ int pstore_register(struct pstore_info *psi) 
		pstore_get_records(0);



	kmsg_dump_register(&pstore_dumper);

	pstore_register_console();



	pstore_timer.expires = jiffies + PSTORE_INTERVAL;

	add_timer(&pstore_timer);

include/linux/pstore.h

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
enum pstore_type_id {

	PSTORE_TYPE_DMESG	= 0,

	PSTORE_TYPE_MCE		= 1,

	PSTORE_TYPE_CONSOLE	= 2,

	PSTORE_TYPE_UNKNOWN	= 255

};