Permalink
Switch branches/tags
Nothing to show
Find file
Fetching contributors…
Cannot retrieve contributors at this time
626 lines (530 sloc) 14.6 KB
/* drivers/misc/apanic.c
*
* Copyright (C) 2009 Google, Inc.
* Author: San Mehat <san@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/wakelock.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/mtd/mtd.h>
#include <linux/notifier.h>
#include <linux/mtd/mtd.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/preempt.h>
extern void ram_console_enable_console(int);
struct panic_header {
u32 magic;
#define PANIC_MAGIC 0xdeadf00d
u32 version;
#define PHDR_VERSION 0x01
u32 console_offset;
u32 console_length;
u32 threads_offset;
u32 threads_length;
};
struct apanic_data {
struct mtd_info *mtd;
struct panic_header curr;
void *bounce;
struct proc_dir_entry *apanic_console;
struct proc_dir_entry *apanic_threads;
};
static struct apanic_data drv_ctx;
static struct work_struct proc_removal_work;
static DEFINE_MUTEX(drv_mutex);
static unsigned int *apanic_bbt;
static unsigned int apanic_erase_blocks;
static unsigned int apanic_good_blocks;
static void set_bb(unsigned int block, unsigned int *bbt)
{
unsigned int flag = 1;
BUG_ON(block >= apanic_erase_blocks);
flag = flag << (block%32);
apanic_bbt[block/32] |= flag;
apanic_good_blocks--;
}
static unsigned int get_bb(unsigned int block, unsigned int *bbt)
{
unsigned int flag;
BUG_ON(block >= apanic_erase_blocks);
flag = 1 << (block%32);
return apanic_bbt[block/32] & flag;
}
static void alloc_bbt(struct mtd_info *mtd, unsigned int *bbt)
{
int bbt_size;
apanic_erase_blocks = (mtd->size)>>(mtd->erasesize_shift);
bbt_size = (apanic_erase_blocks+32)/32;
apanic_bbt = kmalloc(bbt_size*4, GFP_KERNEL);
memset(apanic_bbt, 0, bbt_size*4);
apanic_good_blocks = apanic_erase_blocks;
}
static void scan_bbt(struct mtd_info *mtd, unsigned int *bbt)
{
int i;
for (i = 0; i < apanic_erase_blocks; i++) {
if (mtd->block_isbad(mtd, i*mtd->erasesize))
set_bb(i, apanic_bbt);
}
}
#define APANIC_INVALID_OFFSET 0xFFFFFFFF
static unsigned int phy_offset(struct mtd_info *mtd, unsigned int offset)
{
unsigned int logic_block = offset>>(mtd->erasesize_shift);
unsigned int phy_block;
unsigned good_block = 0;
for (phy_block = 0; phy_block < apanic_erase_blocks; phy_block++) {
if (!get_bb(phy_block, apanic_bbt))
good_block++;
if (good_block == (logic_block + 1))
break;
}
if (good_block != (logic_block + 1))
return APANIC_INVALID_OFFSET;
return offset + ((phy_block-logic_block)<<mtd->erasesize_shift);
}
static void apanic_erase_callback(struct erase_info *done)
{
wait_queue_head_t *wait_q = (wait_queue_head_t *) done->priv;
wake_up(wait_q);
}
static int apanic_proc_read(char *buffer, char **start, off_t offset,
int count, int *peof, void *dat)
{
struct apanic_data *ctx = &drv_ctx;
size_t file_length;
off_t file_offset;
unsigned int page_no;
off_t page_offset;
int rc;
size_t len;
if (!count)
return 0;
mutex_lock(&drv_mutex);
switch ((int) dat) {
case 1: /* apanic_console */
file_length = ctx->curr.console_length;
file_offset = ctx->curr.console_offset;
break;
case 2: /* apanic_threads */
file_length = ctx->curr.threads_length;
file_offset = ctx->curr.threads_offset;
break;
default:
pr_err("Bad dat (%d)\n", (int) dat);
mutex_unlock(&drv_mutex);
return -EINVAL;
}
if ((offset + count) > file_length) {
mutex_unlock(&drv_mutex);
return 0;
}
/* We only support reading a maximum of a flash page */
if (count > ctx->mtd->writesize)
count = ctx->mtd->writesize;
page_no = (file_offset + offset) / ctx->mtd->writesize;
page_offset = (file_offset + offset) % ctx->mtd->writesize;
if (phy_offset(ctx->mtd, (page_no * ctx->mtd->writesize))
== APANIC_INVALID_OFFSET) {
pr_err("apanic: reading an invalid address\n");
mutex_unlock(&drv_mutex);
return -EINVAL;
}
rc = ctx->mtd->read(ctx->mtd,
phy_offset(ctx->mtd, (page_no * ctx->mtd->writesize)),
ctx->mtd->writesize,
&len, ctx->bounce);
#ifdef CONFIG_MTD_RKNAND
if (count > (ctx->mtd->writesize - page_offset))
count = ctx->mtd->writesize - page_offset;
#else
if (page_offset)
count -= page_offset;
#endif
memcpy(buffer, ctx->bounce + page_offset, count);
*start = count;
if ((offset + count) == file_length)
*peof = 1;
mutex_unlock(&drv_mutex);
return count;
}
static void mtd_panic_erase(void)
{
struct apanic_data *ctx = &drv_ctx;
#ifdef CONFIG_MTD_RKNAND
size_t wlen;
memset(ctx->bounce, 0, ctx->mtd->writesize);
ctx->mtd->write(ctx->mtd, 0, ctx->mtd->writesize, &wlen, ctx->bounce);
#else
struct erase_info erase;
DECLARE_WAITQUEUE(wait, current);
wait_queue_head_t wait_q;
int rc, i;
init_waitqueue_head(&wait_q);
erase.mtd = ctx->mtd;
erase.callback = apanic_erase_callback;
erase.len = ctx->mtd->erasesize;
erase.priv = (u_long)&wait_q;
for (i = 0; i < ctx->mtd->size; i += ctx->mtd->erasesize) {
erase.addr = i;
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&wait_q, &wait);
if (get_bb(erase.addr>>ctx->mtd->erasesize_shift, apanic_bbt)) {
printk(KERN_WARNING
"apanic: Skipping erase of bad "
"block @%llx\n", erase.addr);
set_current_state(TASK_RUNNING);
remove_wait_queue(&wait_q, &wait);
continue;
}
rc = ctx->mtd->erase(ctx->mtd, &erase);
if (rc) {
set_current_state(TASK_RUNNING);
remove_wait_queue(&wait_q, &wait);
printk(KERN_ERR
"apanic: Erase of 0x%llx, 0x%llx failed\n",
(unsigned long long) erase.addr,
(unsigned long long) erase.len);
if (rc == -EIO) {
if (ctx->mtd->block_markbad(ctx->mtd,
erase.addr)) {
printk(KERN_ERR
"apanic: Err marking blk bad\n");
goto out;
}
printk(KERN_INFO
"apanic: Marked a bad block"
" @%llx\n", erase.addr);
set_bb(erase.addr>>ctx->mtd->erasesize_shift,
apanic_bbt);
continue;
}
goto out;
}
schedule();
remove_wait_queue(&wait_q, &wait);
}
#endif
printk(KERN_DEBUG "apanic: %s partition erased\n",
CONFIG_APANIC_PLABEL);
out:
return;
}
static void apanic_remove_proc_work(struct work_struct *work)
{
struct apanic_data *ctx = &drv_ctx;
mutex_lock(&drv_mutex);
mtd_panic_erase();
memset(&ctx->curr, 0, sizeof(struct panic_header));
if (ctx->apanic_console) {
remove_proc_entry("apanic_console", NULL);
ctx->apanic_console = NULL;
}
if (ctx->apanic_threads) {
remove_proc_entry("apanic_threads", NULL);
ctx->apanic_threads = NULL;
}
mutex_unlock(&drv_mutex);
}
static int apanic_proc_write(struct file *file, const char __user *buffer,
unsigned long count, void *data)
{
schedule_work(&proc_removal_work);
return count;
}
static void mtd_panic_notify_add(struct mtd_info *mtd)
{
struct apanic_data *ctx = &drv_ctx;
struct panic_header *hdr = ctx->bounce;
size_t len;
int rc;
int proc_entry_created = 0;
if (strcmp(mtd->name, CONFIG_APANIC_PLABEL))
return;
ctx->mtd = mtd;
alloc_bbt(mtd, apanic_bbt);
scan_bbt(mtd, apanic_bbt);
if (apanic_good_blocks == 0) {
printk(KERN_ERR "apanic: no any good blocks?!\n");
goto out_err;
}
rc = mtd->read(mtd, phy_offset(mtd, 0), mtd->writesize,
&len, ctx->bounce);
if (rc && rc == -EBADMSG) {
printk(KERN_WARNING
"apanic: Bad ECC on block 0 (ignored)\n");
} else if (rc && rc != -EUCLEAN) {
printk(KERN_ERR "apanic: Error reading block 0 (%d)\n", rc);
goto out_err;
}
if (len != mtd->writesize) {
printk(KERN_ERR "apanic: Bad read size (%d)\n", rc);
goto out_err;
}
printk(KERN_INFO "apanic: Bound to mtd partition '%s'\n", mtd->name);
if (hdr->magic != PANIC_MAGIC) {
printk(KERN_INFO "apanic: No panic data available\n");
#ifndef CONFIG_MTD_RKNAND
mtd_panic_erase();
#endif
return;
}
if (hdr->version != PHDR_VERSION) {
printk(KERN_INFO "apanic: Version mismatch (%d != %d)\n",
hdr->version, PHDR_VERSION);
#ifndef CONFIG_MTD_RKNAND
mtd_panic_erase();
#endif
return;
}
memcpy(&ctx->curr, hdr, sizeof(struct panic_header));
printk(KERN_INFO "apanic: c(%u, %u) t(%u, %u)\n",
hdr->console_offset, hdr->console_length,
hdr->threads_offset, hdr->threads_length);
if (hdr->console_length) {
ctx->apanic_console = create_proc_entry("apanic_console",
S_IFREG | S_IRUGO, NULL);
if (!ctx->apanic_console)
printk(KERN_ERR "%s: failed creating procfile\n",
__func__);
else {
ctx->apanic_console->read_proc = apanic_proc_read;
ctx->apanic_console->write_proc = apanic_proc_write;
ctx->apanic_console->size = hdr->console_length;
ctx->apanic_console->data = (void *) 1;
proc_entry_created = 1;
}
}
if (hdr->threads_length) {
ctx->apanic_threads = create_proc_entry("apanic_threads",
S_IFREG | S_IRUGO, NULL);
if (!ctx->apanic_threads)
printk(KERN_ERR "%s: failed creating procfile\n",
__func__);
else {
ctx->apanic_threads->read_proc = apanic_proc_read;
ctx->apanic_threads->write_proc = apanic_proc_write;
ctx->apanic_threads->size = hdr->threads_length;
ctx->apanic_threads->data = (void *) 2;
proc_entry_created = 1;
}
}
#ifndef CONFIG_MTD_RKNAND
if (!proc_entry_created)
mtd_panic_erase();
#endif
return;
out_err:
ctx->mtd = NULL;
}
static void mtd_panic_notify_remove(struct mtd_info *mtd)
{
struct apanic_data *ctx = &drv_ctx;
if (mtd == ctx->mtd) {
ctx->mtd = NULL;
printk(KERN_INFO "apanic: Unbound from %s\n", mtd->name);
}
}
static struct mtd_notifier mtd_panic_notifier = {
.add = mtd_panic_notify_add,
.remove = mtd_panic_notify_remove,
};
static int in_panic = 0;
static int apanic_writeflashpage(struct mtd_info *mtd, loff_t to,
const u_char *buf)
{
int rc;
size_t wlen;
int panic = in_interrupt() | in_atomic();
if (panic && !mtd->panic_write) {
printk(KERN_EMERG "%s: No panic_write available\n", __func__);
return 0;
} else if (!panic && !mtd->write) {
printk(KERN_EMERG "%s: No write available\n", __func__);
return 0;
}
to = phy_offset(mtd, to);
if (to == APANIC_INVALID_OFFSET) {
printk(KERN_EMERG "apanic: write to invalid address\n");
return 0;
}
if (panic)
rc = mtd->panic_write(mtd, to, mtd->writesize, &wlen, buf);
else
rc = mtd->write(mtd, to, mtd->writesize, &wlen, buf);
if (rc) {
printk(KERN_EMERG
"%s: Error writing data to flash (%d)\n",
__func__, rc);
return rc;
}
return wlen;
}
extern int log_buf_copy(char *dest, int idx, int len);
extern void log_buf_clear(void);
/*
* Writes the contents of the console to the specified offset in flash.
* Returns number of bytes written
*/
static int apanic_write_console(struct mtd_info *mtd, unsigned int off)
{
struct apanic_data *ctx = &drv_ctx;
int saved_oip;
int idx = 0;
int rc, rc2;
unsigned int last_chunk = 0;
while (!last_chunk) {
saved_oip = oops_in_progress;
oops_in_progress = 1;
rc = log_buf_copy(ctx->bounce, idx, mtd->writesize);
if (rc < 0)
break;
if (rc != mtd->writesize)
last_chunk = rc;
oops_in_progress = saved_oip;
if (rc <= 0)
break;
if (rc != mtd->writesize)
memset(ctx->bounce + rc, 0, mtd->writesize - rc);
rc2 = apanic_writeflashpage(mtd, off, ctx->bounce);
if (rc2 <= 0) {
printk(KERN_EMERG
"apanic: Flash write failed (%d)\n", rc2);
return idx;
}
if (!last_chunk)
idx += rc2;
else
idx += last_chunk;
off += rc2;
}
return idx;
}
static int apanic(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct apanic_data *ctx = &drv_ctx;
struct panic_header *hdr = (struct panic_header *) ctx->bounce;
int console_offset = 0;
int console_len = 0;
int threads_offset = 0;
int threads_len = 0;
int rc;
if (in_panic)
return NOTIFY_DONE;
in_panic = 1;
#ifdef CONFIG_PREEMPT
/* Ensure that cond_resched() won't try to preempt anybody */
add_preempt_count(PREEMPT_ACTIVE);
#endif
touch_softlockup_watchdog();
if (!ctx->mtd)
goto out;
if (ctx->curr.magic) {
printk(KERN_EMERG "Crash partition in use!\n");
goto out;
}
console_offset = ctx->mtd->erasesize;
/*
* Write out the console
*/
console_len = apanic_write_console(ctx->mtd, console_offset);
if (console_len < 0) {
printk(KERN_EMERG "Error writing console to panic log! (%d)\n",
console_len);
console_len = 0;
}
/*
* Write out all threads
*/
threads_offset = ALIGN(console_offset + console_len,
ctx->mtd->writesize);
if (!threads_offset)
threads_offset = ctx->mtd->writesize;
#ifdef CONFIG_ANDROID_RAM_CONSOLE
ram_console_enable_console(0);
#endif
log_buf_clear();
show_state_filter(0);
threads_len = apanic_write_console(ctx->mtd, threads_offset);
if (threads_len < 0) {
printk(KERN_EMERG "Error writing threads to panic log! (%d)\n",
threads_len);
threads_len = 0;
}
/*
* Finally write the panic header
*/
memset(ctx->bounce, 0, PAGE_SIZE);
hdr->magic = PANIC_MAGIC;
hdr->version = PHDR_VERSION;
hdr->console_offset = console_offset;
hdr->console_length = console_len;
hdr->threads_offset = threads_offset;
hdr->threads_length = threads_len;
rc = apanic_writeflashpage(ctx->mtd, 0, ctx->bounce);
if (rc <= 0) {
printk(KERN_EMERG "apanic: Header write failed (%d)\n",
rc);
goto out;
}
printk(KERN_EMERG "apanic: Panic dump sucessfully written to flash\n");
out:
#ifdef CONFIG_PREEMPT
sub_preempt_count(PREEMPT_ACTIVE);
#endif
in_panic = 0;
return NOTIFY_DONE;
}
static struct notifier_block panic_blk = {
.notifier_call = apanic,
};
static int panic_dbg_get(void *data, u64 *val)
{
apanic(NULL, 0, NULL);
return 0;
}
static int panic_dbg_set(void *data, u64 val)
{
BUG();
return -1;
}
DEFINE_SIMPLE_ATTRIBUTE(panic_dbg_fops, panic_dbg_get, panic_dbg_set, "%llu\n");
int __init apanic_init(void)
{
register_mtd_user(&mtd_panic_notifier);
atomic_notifier_chain_register(&panic_notifier_list, &panic_blk);
debugfs_create_file("apanic", 0644, NULL, NULL, &panic_dbg_fops);
memset(&drv_ctx, 0, sizeof(drv_ctx));
drv_ctx.bounce = (void *) __get_free_page(GFP_KERNEL);
INIT_WORK(&proc_removal_work, apanic_remove_proc_work);
printk(KERN_INFO "Android kernel panic handler initialized (bind=%s)\n",
CONFIG_APANIC_PLABEL);
return 0;
}
module_init(apanic_init);