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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>
This commit is contained in:
Anton Vorontsov 2012-05-26 06:20:19 -07:00 committed by Greg Kroah-Hartman
parent 89a86a2da3
commit f29e5956ae
4 changed files with 48 additions and 0 deletions
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7
fs/pstore/Kconfig
View File

@ -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

3
fs/pstore/inode.c
View File

@ -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;

37
fs/pstore/platform.c
View File

@ -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 @@ 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);

1
include/linux/pstore.h
View File

@ -29,6 +29,7 @@
enum pstore_type_id {
PSTORE_TYPE_DMESG = 0,
PSTORE_TYPE_MCE = 1,
PSTORE_TYPE_CONSOLE = 2,
PSTORE_TYPE_UNKNOWN = 255
};