cregit-Linux how code gets into the kernel

Release 4.14 drivers/mtd/mtdoops.c

Directory: drivers/mtd
/*
 * MTD Oops/Panic logger
 *
 * Copyright © 2007 Nokia Corporation. All rights reserved.
 *
 * Author: Richard Purdie <rpurdie@openedhand.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/vmalloc.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/mtd/mtd.h>
#include <linux/kmsg_dump.h>

/* Maximum MTD partition size */

#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)


#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00

#define MTDOOPS_HEADER_SIZE   8


static unsigned long record_size = 4096;
module_param(record_size, ulong, 0400);
MODULE_PARM_DESC(record_size,
		"record size for MTD OOPS pages in bytes (default 4096)");


static char mtddev[80];
module_param_string(mtddev, mtddev, 80, 0400);
MODULE_PARM_DESC(mtddev,
		"name or index number of the MTD device to use");


static int dump_oops = 1;
module_param(dump_oops, int, 0600);
MODULE_PARM_DESC(dump_oops,
		"set to 1 to dump oopses, 0 to only dump panics (default 1)");


static struct mtdoops_context {
	
struct kmsg_dumper dump;

	
int mtd_index;
	
struct work_struct work_erase;
	
struct work_struct work_write;
	
struct mtd_info *mtd;
	
int oops_pages;
	
int nextpage;
	
int nextcount;
	
unsigned long *oops_page_used;

	
void *oops_buf;

} oops_cxt;


static void mark_page_used(struct mtdoops_context *cxt, int page) { set_bit(page, cxt->oops_page_used); }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström23100.00%1100.00%
Total23100.00%1100.00%


static void mark_page_unused(struct mtdoops_context *cxt, int page) { clear_bit(page, cxt->oops_page_used); }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström23100.00%1100.00%
Total23100.00%1100.00%


static int page_is_used(struct mtdoops_context *cxt, int page) { return test_bit(page, cxt->oops_page_used); }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström24100.00%1100.00%
Total24100.00%1100.00%


static void mtdoops_erase_callback(struct erase_info *done) { wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv; wake_up(wait_q); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie28100.00%1100.00%
Total28100.00%1100.00%


static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset) { struct mtd_info *mtd = cxt->mtd; u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize; u32 start_page = start_page_offset / record_size; u32 erase_pages = mtd->erasesize / record_size; struct erase_info erase; DECLARE_WAITQUEUE(wait, current); wait_queue_head_t wait_q; int ret; int page; init_waitqueue_head(&wait_q); erase.mtd = mtd; erase.callback = mtdoops_erase_callback; erase.addr = offset; erase.len = mtd->erasesize; erase.priv = (u_long)&wait_q; set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&wait_q, &wait); ret = mtd_erase(mtd, &erase); if (ret) { set_current_state(TASK_RUNNING); remove_wait_queue(&wait_q, &wait); printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n", (unsigned long long)erase.addr, (unsigned long long)erase.len, mtddev); return ret; } schedule(); /* Wait for erase to finish. */ remove_wait_queue(&wait_q, &wait); /* Mark pages as unused */ for (page = start_page; page < start_page + erase_pages; page++) mark_page_unused(cxt, page); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie14764.76%114.29%
Simon Kågström6829.96%342.86%
Adrian Hunter104.41%114.29%
Artem B. Bityutskiy20.88%228.57%
Total227100.00%7100.00%


static void mtdoops_inc_counter(struct mtdoops_context *cxt) { cxt->nextpage++; if (cxt->nextpage >= cxt->oops_pages) cxt->nextpage = 0; cxt->nextcount++; if (cxt->nextcount == 0xffffffff) cxt->nextcount = 0; if (page_is_used(cxt, cxt->nextpage)) { schedule_work(&cxt->work_erase); return; } printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n", cxt->nextpage, cxt->nextcount); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie8496.55%360.00%
Simon Kågström22.30%120.00%
Artem B. Bityutskiy11.15%120.00%
Total87100.00%5100.00%

/* Scheduled work - when we can't proceed without erasing a block */
static void mtdoops_workfunc_erase(struct work_struct *work) { struct mtdoops_context *cxt = container_of(work, struct mtdoops_context, work_erase); struct mtd_info *mtd = cxt->mtd; int i = 0, j, ret, mod; /* We were unregistered */ if (!mtd) return; mod = (cxt->nextpage * record_size) % mtd->erasesize; if (mod != 0) { cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size); if (cxt->nextpage >= cxt->oops_pages) cxt->nextpage = 0; } while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) { badblock: printk(KERN_WARNING "mtdoops: bad block at %08lx\n", cxt->nextpage * record_size); i++; cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size); if (cxt->nextpage >= cxt->oops_pages) cxt->nextpage = 0; if (i == cxt->oops_pages / (mtd->erasesize / record_size)) { printk(KERN_ERR "mtdoops: all blocks bad!\n"); return; } } if (ret < 0) { printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n"); return; } for (j = 0, ret = -1; (j < 3) && (ret < 0); j++) ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size); if (ret >= 0) { printk(KERN_DEBUG "mtdoops: ready %d, %d\n", cxt->nextpage, cxt->nextcount); return; } if (ret == -EIO) { ret = mtd_block_markbad(mtd, cxt->nextpage * record_size); if (ret < 0 && ret != -EOPNOTSUPP) { printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n"); return; } } goto badblock; }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie29088.41%436.36%
Brian Norris185.49%19.09%
Simon Kågström103.05%218.18%
Artem B. Bityutskiy103.05%436.36%
Total328100.00%11100.00%


static void mtdoops_write(struct mtdoops_context *cxt, int panic) { struct mtd_info *mtd = cxt->mtd; size_t retlen; u32 *hdr; int ret; /* Add mtdoops header to the buffer */ hdr = cxt->oops_buf; hdr[0] = cxt->nextcount; hdr[1] = MTDOOPS_KERNMSG_MAGIC; if (panic) { ret = mtd_panic_write(mtd, cxt->nextpage * record_size, record_size, &retlen, cxt->oops_buf); if (ret == -EOPNOTSUPP) { printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n"); return; } } else ret = mtd_write(mtd, cxt->nextpage * record_size, record_size, &retlen, cxt->oops_buf); if (retlen != record_size || ret < 0) printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n", cxt->nextpage * record_size, retlen, record_size, ret); mark_page_used(cxt, cxt->nextpage); memset(cxt->oops_buf, 0xff, record_size); mtdoops_inc_counter(cxt); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie10760.80%333.33%
Simon Kågström4927.84%333.33%
Artem B. Bityutskiy2011.36%333.33%
Total176100.00%9100.00%


static void mtdoops_workfunc_write(struct work_struct *work) { struct mtdoops_context *cxt = container_of(work, struct mtdoops_context, work_write); mtdoops_write(cxt, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie33100.00%1100.00%
Total33100.00%1100.00%


static void find_next_position(struct mtdoops_context *cxt) { struct mtd_info *mtd = cxt->mtd; int ret, page, maxpos = 0; u32 count[2], maxcount = 0xffffffff; size_t retlen; for (page = 0; page < cxt->oops_pages; page++) { if (mtd_block_isbad(mtd, page * record_size)) continue; /* Assume the page is used */ mark_page_used(cxt, page); ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE, &retlen, (u_char *)&count[0]); if (retlen != MTDOOPS_HEADER_SIZE || (ret < 0 && !mtd_is_bitflip(ret))) { printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n", page * record_size, retlen, MTDOOPS_HEADER_SIZE, ret); continue; } if (count[0] == 0xffffffff && count[1] == 0xffffffff) mark_page_unused(cxt, page); if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC) continue; if (maxcount == 0xffffffff) { maxcount = count[0]; maxpos = page; } else if (count[0] < 0x40000000 && maxcount > 0xc0000000) { maxcount = count[0]; maxpos = page; } else if (count[0] > maxcount && count[0] < 0xc0000000) { maxcount = count[0]; maxpos = page; } else if (count[0] > maxcount && count[0] > 0xc0000000 && maxcount > 0x80000000) { maxcount = count[0]; maxpos = page; } } if (maxcount == 0xffffffff) { cxt->nextpage = cxt->oops_pages - 1; cxt->nextcount = 0; } else { cxt->nextpage = maxpos; cxt->nextcount = maxcount; } mtdoops_inc_counter(cxt); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie26679.17%433.33%
Simon Kågström3811.31%325.00%
Matthieu Castet154.46%18.33%
Roman Tereshonkov113.27%18.33%
Brian Norris41.19%18.33%
Artem B. Bityutskiy20.60%216.67%
Total336100.00%12100.00%


static void mtdoops_do_dump(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason) { struct mtdoops_context *cxt = container_of(dumper, struct mtdoops_context, dump); /* Only dump oopses if dump_oops is set */ if (reason == KMSG_DUMP_OOPS && !dump_oops) return; kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE, record_size - MTDOOPS_HEADER_SIZE, NULL); /* Panics must be written immediately */ if (reason != KMSG_DUMP_OOPS) mtdoops_write(cxt, 1); /* For other cases, schedule work to write it "nicely" */ schedule_work(&cxt->work_write); }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström4453.01%228.57%
Richard Purdie2732.53%228.57%
Kay Sievers78.43%114.29%
Adrian Hunter33.61%114.29%
Motohiro Kosaki22.41%114.29%
Total83100.00%7100.00%


static void mtdoops_notify_add(struct mtd_info *mtd) { struct mtdoops_context *cxt = &oops_cxt; u64 mtdoops_pages = div_u64(mtd->size, record_size); int err; if (!strcmp(mtd->name, mtddev)) cxt->mtd_index = mtd->index; if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) return; if (mtd->size < mtd->erasesize * 2) { printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n", mtd->index); return; } if (mtd->erasesize < record_size) { printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n", mtd->index); return; } if (mtd->size > MTDOOPS_MAX_MTD_SIZE) { printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n", mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024); return; } /* oops_page_used is a bit field */ cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages, BITS_PER_LONG) * sizeof(unsigned long)); if (!cxt->oops_page_used) { printk(KERN_ERR "mtdoops: could not allocate page array\n"); return; } cxt->dump.max_reason = KMSG_DUMP_OOPS; cxt->dump.dump = mtdoops_do_dump; err = kmsg_dump_register(&cxt->dump); if (err) { printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err); vfree(cxt->oops_page_used); cxt->oops_page_used = NULL; return; } cxt->mtd = mtd; cxt->oops_pages = (int)mtd->size / record_size; find_next_position(cxt); printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index); }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström13851.30%110.00%
Richard Purdie11040.89%550.00%
Kay Sievers82.97%110.00%
Roman Tereshonkov62.23%110.00%
Adrian Hunter51.86%110.00%
Peter Korsgaard20.74%110.00%
Total269100.00%10100.00%


static void mtdoops_notify_remove(struct mtd_info *mtd) { struct mtdoops_context *cxt = &oops_cxt; if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0) return; if (kmsg_dump_unregister(&cxt->dump) < 0) printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n"); cxt->mtd = NULL; flush_work(&cxt->work_erase); flush_work(&cxt->work_write); }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström2836.84%120.00%
Richard Purdie2634.21%120.00%
Tejun Heo1519.74%240.00%
Adrian Hunter79.21%120.00%
Total76100.00%5100.00%

static struct mtd_notifier mtdoops_notifier = { .add = mtdoops_notify_add, .remove = mtdoops_notify_remove, };
static int __init mtdoops_init(void) { struct mtdoops_context *cxt = &oops_cxt; int mtd_index; char *endp; if (strlen(mtddev) == 0) { printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n"); return -EINVAL; } if ((record_size & 4095) != 0) { printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n"); return -EINVAL; } if (record_size < 4096) { printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n"); return -EINVAL; } /* Setup the MTD device to use */ cxt->mtd_index = -1; mtd_index = simple_strtoul(mtddev, &endp, 0); if (*endp == '\0') cxt->mtd_index = mtd_index; cxt->oops_buf = vmalloc(record_size); if (!cxt->oops_buf) { printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n"); return -ENOMEM; } memset(cxt->oops_buf, 0xff, record_size); INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase); INIT_WORK(&cxt->work_write, mtdoops_workfunc_write); register_mtd_user(&mtdoops_notifier); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Simon Kågström10254.84%240.00%
Richard Purdie7841.94%240.00%
Artem B. Bityutskiy63.23%120.00%
Total186100.00%5100.00%


static void __exit mtdoops_exit(void) { struct mtdoops_context *cxt = &oops_cxt; unregister_mtd_user(&mtdoops_notifier); vfree(cxt->oops_buf); vfree(cxt->oops_page_used); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie2978.38%133.33%
Simon Kågström821.62%266.67%
Total37100.00%3100.00%

module_init(mtdoops_init); module_exit(mtdoops_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");

Overall Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie133262.21%923.68%
Simon Kågström65130.41%410.53%
Artem B. Bityutskiy411.91%923.68%
Adrian Hunter251.17%37.89%
Brian Norris221.03%25.26%
Roman Tereshonkov170.79%25.26%
Tejun Heo150.70%25.26%
Matthieu Castet150.70%12.63%
Kay Sievers150.70%12.63%
David Woodhouse30.14%25.26%
Peter Korsgaard20.09%12.63%
Motohiro Kosaki20.09%12.63%
Adrian Bunk10.05%12.63%
Total2141100.00%38100.00%
Directory: drivers/mtd
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.