From 01c99685db1325935e8b983c240397543fab9c96 Mon Sep 17 00:00:00 2001 From: San Mehat Date: Tue, 1 Sep 2009 13:43:01 -0700 Subject: [PATCH] drivers: apanic: Android kernel panic handler. This driver triggers when the kernel panics and attempts to write critical debug data to the flash. Signed-off-by: San Mehat drivers: apanic: checkpatch fixes Signed-off-by: San Mehat apanic: Fix a few cases of calling non-atomic things from atomic We need to pay special care to not enrage cond_resched(), and the base nand bb stuff calls schedule() so thats out. Signed-off-by: San Mehat --- drivers/misc/Kconfig | 16 +- drivers/misc/Makefile | 1 + drivers/misc/apanic.c | 541 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 557 insertions(+), 1 deletion(-) create mode 100644 drivers/misc/apanic.c diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 0da53642a40e..1c79dbf72b09 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -512,7 +512,21 @@ config WL127X_RFKILL ---help--- Creates an rfkill entry in sysfs for power control of Bluetooth TI wl127x chips. - + +config APANIC + bool "Android kernel panic diagnostics driver" + default n + ---help--- + Driver which handles kernel panics and attempts to write + critical debugging data to flash. + +config APANIC_PLABEL + string "Android panic dump flash partition label" + default "kpanic" + ---help--- + If your platform uses a different flash partition label for storing + crashdumps, enter it here. + source "drivers/misc/c2port/Kconfig" source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 2b880207dfcf..42d698081a53 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -50,3 +50,4 @@ obj-$(CONFIG_AB8500_PWM) += ab8500-pwm.o obj-y += lis3lv02d/ obj-y += carma/ obj-$(CONFIG_WL127X_RFKILL) += wl127x-rfkill.o +obj-$(CONFIG_APANIC) += apanic.o diff --git a/drivers/misc/apanic.c b/drivers/misc/apanic.c new file mode 100644 index 000000000000..fde087122473 --- /dev/null +++ b/drivers/misc/apanic.c @@ -0,0 +1,541 @@ +/* drivers/misc/apanic.c + * + * Copyright (C) 2009 Google, Inc. + * Author: San Mehat + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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; +}; + +#define CHECK_BB 0 + +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 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; + + rc = ctx->mtd->read(ctx->mtd, + (page_no * ctx->mtd->writesize), + ctx->mtd->writesize, + &len, ctx->bounce); + + if (page_offset) + count -= page_offset; + 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; + 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); + + rc = ctx->mtd->block_isbad(ctx->mtd, erase.addr); + if (rc < 0) { + printk(KERN_ERR + "apanic: Bad block check " + "failed (%d)\n", rc); + goto out; + } + if (rc) { + 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); + continue; + } + goto out; + } + schedule(); + remove_wait_queue(&wait_q, &wait); + } + 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; + + if (strcmp(mtd->name, CONFIG_APANIC_PLABEL)) + return; + + ctx->mtd = mtd; + + if (mtd->block_isbad(mtd, 0)) { + printk(KERN_ERR "apanic: Offset 0 bad block. Boourns!\n"); + goto out_err; + } + + rc = mtd->read(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"); + mtd_panic_erase(); + return; + } + + if (hdr->version != PHDR_VERSION) { + printk(KERN_INFO "apanic: Version mismatch (%d != %d)\n", + hdr->version, PHDR_VERSION); + mtd_panic_erase(); + 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; + } + } + + 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; + } + } + + 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; + } + + 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); +#if CHECK_BB +check_badblock: + rc = mtd->block_isbad(mtd, off); + if (rc < 0) { + printk(KERN_ERR + "apanic: Bad block check " + "failed (%d)\n", rc); + } + if (rc) { + printk(KERN_WARNING + "apanic: Skipping over bad " + "block @%x\n", off); + off += mtd->erasesize; + printk("chk %u %llu\n", off, mtd->size); + if (off >= mtd->size) { + printk(KERN_EMERG + "apanic: Too many bad blocks!\n"); + return -EIO; + } + goto check_badblock; + } +#endif + + rc2 = apanic_writeflashpage(mtd, off, ctx->bounce); + if (rc2 <= 0) { + printk(KERN_EMERG + "apanic: Flash write failed (%d)\n", rc2); + return rc2; + } + 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 + + if (!ctx->mtd) + goto out; + + if (ctx->curr.magic) { + printk(KERN_EMERG "Crash partition in use!\n"); + goto out; + } + console_offset = ctx->mtd->writesize; + + /* + * 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; + + 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); -- 2.34.1