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 --- fs/pstore/Kconfig | 7 +++++++ fs/pstore/inode.c | 3 +++ fs/pstore/platform.c | 37 +++++++++++++++++++++++++++++++++++++ include/linux/pstore.h | 1 + 4 files changed, 48 insertions(+)
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 23ade26..d044de6 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -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 diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 49b40ea..fda1331 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -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; 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 @@ 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); diff --git a/include/linux/pstore.h b/include/linux/pstore.h index e1461e1..1bd014b 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -29,6 +29,7 @@ enum pstore_type_id { PSTORE_TYPE_DMESG = 0, PSTORE_TYPE_MCE = 1, + PSTORE_TYPE_CONSOLE = 2, PSTORE_TYPE_UNKNOWN = 255 };