summaryrefslogtreecommitdiff
path: root/fs/pstore/platform.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/pstore/platform.c')
-rw-r--r--fs/pstore/platform.c131
1 files changed, 111 insertions, 20 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 03ce7a9b81cc..422962ae9fc2 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>
@@ -29,6 +31,7 @@
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
+#include <linux/jiffies.h>
#include <linux/workqueue.h>
#include "internal.h"
@@ -38,7 +41,12 @@
* whether the system is actually still running well enough
* to let someone see the entry
*/
-#define PSTORE_INTERVAL (60 * HZ)
+static int pstore_update_ms = -1;
+module_param_named(update_ms, pstore_update_ms, int, 0600);
+MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
+ "(default is -1, which means runtime updates are disabled; "
+ "enabling this option is not safe, it may lead to further "
+ "corruption on Oopses)");
static int pstore_new_entry;
@@ -53,7 +61,7 @@ static DECLARE_WORK(pstore_work, pstore_dowork);
* calls to pstore_register()
*/
static DEFINE_SPINLOCK(pstore_lock);
-static struct pstore_info *psinfo;
+struct pstore_info *psinfo;
static char *backend;
@@ -88,6 +96,27 @@ static const char *get_reason_str(enum kmsg_dump_reason reason)
}
}
+bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
+{
+ /*
+ * In case of NMI path, pstore shouldn't be blocked
+ * regardless of reason.
+ */
+ if (in_nmi())
+ return true;
+
+ switch (reason) {
+ /* In panic case, other cpus are stopped by smp_send_stop(). */
+ case KMSG_DUMP_PANIC:
+ /* Emergency restart shouldn't be blocked by spin lock. */
+ case KMSG_DUMP_EMERG:
+ return true;
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
+
/*
* callback from kmsg_dump. (s2,l2) has the most recently
* written bytes, older bytes are in (s1,l1). Save as much
@@ -106,10 +135,12 @@ static void pstore_dump(struct kmsg_dumper *dumper,
why = get_reason_str(reason);
- if (in_nmi()) {
- is_locked = spin_trylock(&psinfo->buf_lock);
- if (!is_locked)
- pr_err("pstore dump routine blocked in NMI, may corrupt error record\n");
+ if (pstore_cannot_block_path(reason)) {
+ is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
+ if (!is_locked) {
+ pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
+ , in_nmi() ? "NMI" : why);
+ }
} else
spin_lock_irqsave(&psinfo->buf_lock, flags);
oopscount++;
@@ -128,16 +159,16 @@ static void pstore_dump(struct kmsg_dumper *dumper,
break;
ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
- hsize + len, psinfo);
+ oopscount, hsize, hsize + len, psinfo);
if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
pstore_new_entry = 1;
total += hsize + len;
part++;
}
- if (in_nmi()) {
+ if (pstore_cannot_block_path(reason)) {
if (is_locked)
- spin_unlock(&psinfo->buf_lock);
+ spin_unlock_irqrestore(&psinfo->buf_lock, flags);
} else
spin_unlock_irqrestore(&psinfo->buf_lock, flags);
}
@@ -146,6 +177,57 @@ 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;
+ u64 id;
+
+ if (c > psinfo->bufsize)
+ c = psinfo->bufsize;
+
+ if (oops_in_progress) {
+ if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
+ break;
+ } else {
+ spin_lock_irqsave(&psinfo->buf_lock, flags);
+ }
+ memcpy(psinfo->buf, s, c);
+ psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 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
+
+static int pstore_write_compat(enum pstore_type_id type,
+ enum kmsg_dump_reason reason,
+ u64 *id, unsigned int part, int count,
+ size_t hsize, size_t size,
+ struct pstore_info *psi)
+{
+ return psi->write_buf(type, reason, id, part, psinfo->buf, hsize,
+ size, psi);
+}
+
/*
* platform specific persistent storage driver registers with
* us here. If pstore is already mounted, call the platform
@@ -159,17 +241,17 @@ int pstore_register(struct pstore_info *psi)
{
struct module *owner = psi->owner;
+ if (backend && strcmp(backend, psi->name))
+ return -EPERM;
+
spin_lock(&pstore_lock);
if (psinfo) {
spin_unlock(&pstore_lock);
return -EBUSY;
}
- if (backend && strcmp(backend, psi->name)) {
- spin_unlock(&pstore_lock);
- return -EINVAL;
- }
-
+ if (!psi->write)
+ psi->write = pstore_write_compat;
psinfo = psi;
mutex_init(&psinfo->read_mutex);
spin_unlock(&pstore_lock);
@@ -183,9 +265,17 @@ int pstore_register(struct pstore_info *psi)
pstore_get_records(0);
kmsg_dump_register(&pstore_dumper);
+ pstore_register_console();
+ pstore_register_ftrace();
+
+ if (pstore_update_ms >= 0) {
+ pstore_timer.expires = jiffies +
+ msecs_to_jiffies(pstore_update_ms);
+ add_timer(&pstore_timer);
+ }
- pstore_timer.expires = jiffies + PSTORE_INTERVAL;
- add_timer(&pstore_timer);
+ pr_info("pstore: Registered %s as persistent store backend\n",
+ psi->name);
return 0;
}
@@ -203,6 +293,7 @@ void pstore_get_records(int quiet)
char *buf = NULL;
ssize_t size;
u64 id;
+ int count;
enum pstore_type_id type;
struct timespec time;
int failed = 0, rc;
@@ -214,9 +305,9 @@ void pstore_get_records(int quiet)
if (psi->open && psi->open(psi))
goto out;
- while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) {
- rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size,
- time, psi);
+ while ((size = psi->read(&id, &type, &count, &time, &buf, psi)) > 0) {
+ rc = pstore_mkfile(type, psi->name, id, count, buf,
+ (size_t)size, time, psi);
kfree(buf);
buf = NULL;
if (rc && (rc != -EEXIST || !quiet))
@@ -244,7 +335,7 @@ static void pstore_timefunc(unsigned long dummy)
schedule_work(&pstore_work);
}
- mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL);
+ mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
}
module_param(backend, charp, 0444);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-17 12:23:47 +0000