Commit cc9c4d1b authored by WeiXiong Liao's avatar WeiXiong Liao Committed by Kees Cook
Browse files

pstore/zone,blk: Add console frontend support 



Support backend for console. To enable console backend, just make
console_size be greater than 0 and a multiple of 4096.

Signed-off-by: default avatarWeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-5-keescook@chromium.org/


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 0dc06826

fs/pstore/Kconfig

+15 −3
Original line number Diff line number Diff line
@@ -180,11 +180,11 @@ config PSTORE_BLK_BLKDEV 
	help

	  Which block device should be used for pstore/blk.



	  It accept the following variants:

	  It accepts the following variants:

	  1) <hex_major><hex_minor> device number in hexadecimal representation,

	     with no leading 0x, for example b302.

	  2) /dev/<disk_name> represents the device number of disk

	  3) /dev/<disk_name><decimal> represents the device number

	  2) /dev/<disk_name> represents the device name of disk

	  3) /dev/<disk_name><decimal> represents the device name and number

	     of partition - device number of disk plus the partition number

	  4) /dev/<disk_name>p<decimal> - same as the above, this form is

	     used when disk name of partitioned disk ends with a digit.
@@ -236,3 +236,15 @@ config PSTORE_BLK_PMSG_SIZE 


	  NOTE that, both Kconfig and module parameters can configure

	  pstore/blk, but module parameters have priority over Kconfig.



config PSTORE_BLK_CONSOLE_SIZE

	int "Size in Kbytes of console log to store"

	depends on PSTORE_BLK

	depends on PSTORE_CONSOLE

	default 64

	help

	  This just sets size of console log (console_size) to store via

	  pstore/blk. The size is in KB and must be a multiple of 4.



	  NOTE that, both Kconfig and module parameters can configure

	  pstore/blk, but module parameters have priority over Kconfig.

fs/pstore/blk.c

+11 −1
Original line number Diff line number Diff line
@@ -35,6 +35,14 @@ static long pmsg_size = -1; 
module_param(pmsg_size, long, 0400);

MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes");



#if IS_ENABLED(CONFIG_PSTORE_CONSOLE)

static long console_size = CONFIG_PSTORE_BLK_CONSOLE_SIZE;

#else

static long console_size = -1;

#endif

module_param(console_size, long, 0400);

MODULE_PARM_DESC(console_size, "console size in kbytes");



/*

 * blkdev - the block device to use for pstore storage

 *
@@ -91,7 +99,8 @@ struct bdev_info { 
 *		whole disk).

 *		On success, the number of bytes should be returned, others

 *		means error.

 * @write:	The same as @read.

 * @write:	The same as @read, but the following error number:

 *		-EBUSY means try to write again later.

 * @panic_write:The write operation only used for panic case. It's optional

 *		if you do not care panic log. The parameters and return value

 *		are the same as @read.
@@ -142,6 +151,7 @@ static int psblk_register_do(struct pstore_device_info *dev) 


	verify_size(kmsg_size, 4096, dev->flags & PSTORE_FLAGS_DMESG);

	verify_size(pmsg_size, 4096, dev->flags & PSTORE_FLAGS_PMSG);

	verify_size(console_size, 4096, dev->flags & PSTORE_FLAGS_CONSOLE);

#undef verify_size



	pstore_zone_info->total_size = dev->total_size;

fs/pstore/zone.c

+76 −5
Original line number Diff line number Diff line
@@ -91,10 +91,12 @@ struct pstore_zone { 
 *

 * @kpszs: kmsg dump storage zones

 * @ppsz: pmsg storage zone

 * @cpsz: console storage zone

 * @kmsg_max_cnt: max count of @kpszs

 * @kmsg_read_cnt: counter of total read kmsg dumps

 * @kmsg_write_cnt: counter of total kmsg dump writes

 * @pmsg_read_cnt: counter of total read pmsg zone

 * @console_read_cnt: counter of total read console zone

 * @oops_counter: counter of oops dumps

 * @panic_counter: counter of panic dumps

 * @recovered: whether finished recovering data from storage
@@ -106,10 +108,12 @@ struct pstore_zone { 
struct psz_context {

	struct pstore_zone **kpszs;

	struct pstore_zone *ppsz;

	struct pstore_zone *cpsz;

	unsigned int kmsg_max_cnt;

	unsigned int kmsg_read_cnt;

	unsigned int kmsg_write_cnt;

	unsigned int pmsg_read_cnt;

	unsigned int console_read_cnt;

	/*

	 * These counters should be calculated during recovery.

	 * It records the oops/panic times after crashes rather than boots.
@@ -129,6 +133,9 @@ struct psz_context { 
};

static struct psz_context pstore_zone_cxt;



static void psz_flush_all_dirty_zones(struct work_struct *);

static DECLARE_DELAYED_WORK(psz_cleaner, psz_flush_all_dirty_zones);



/**

 * enum psz_flush_mode - flush mode for psz_zone_write()

 *
@@ -237,6 +244,9 @@ static int psz_zone_write(struct pstore_zone *zone, 
	return 0;

dirty:

	atomic_set(&zone->dirty, true);

	/* flush dirty zones nicely */

	if (wcnt == -EBUSY && !is_on_panic())

		schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(500));

	return -EBUSY;

}
@@ -293,6 +303,21 @@ static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new) 
	return 0;

}



static void psz_flush_all_dirty_zones(struct work_struct *work)

{

	struct psz_context *cxt = &pstore_zone_cxt;

	int ret = 0;



	if (cxt->ppsz)

		ret |= psz_flush_dirty_zone(cxt->ppsz);

	if (cxt->cpsz)

		ret |= psz_flush_dirty_zone(cxt->cpsz);

	if (cxt->kpszs)

		ret |= psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt);

	if (ret && cxt->pstore_zone_info)

		schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(1000));

}



static int psz_kmsg_recover_data(struct psz_context *cxt)

{

	struct pstore_zone_info *info = cxt->pstore_zone_info;
@@ -545,6 +570,10 @@ static inline int psz_recovery(struct psz_context *cxt) 
		goto out;



	ret = psz_recover_zone(cxt, cxt->ppsz);

	if (ret)

		goto out;



	ret = psz_recover_zone(cxt, cxt->cpsz);



out:

	if (unlikely(ret))
@@ -562,6 +591,7 @@ static int psz_pstore_open(struct pstore_info *psi) 


	cxt->kmsg_read_cnt = 0;

	cxt->pmsg_read_cnt = 0;

	cxt->console_read_cnt = 0;

	return 0;

}
@@ -626,8 +656,9 @@ static int psz_pstore_erase(struct pstore_record *record) 
		return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record);

	case PSTORE_TYPE_PMSG:

		return psz_record_erase(cxt, cxt->ppsz);

	default:

		return -EINVAL;

	case PSTORE_TYPE_CONSOLE:

		return psz_record_erase(cxt, cxt->cpsz);

	default: return -EINVAL;

	}

}
@@ -690,9 +721,10 @@ static int notrace psz_kmsg_write(struct psz_context *cxt, 
		return -ENOSPC;



	ret = psz_kmsg_write_record(cxt, record);

	if (!ret) {

	if (!ret && is_on_panic()) {

		/* ensure all data are flushed to storage when panic */

		pr_debug("try to flush other dirty zones\n");

		psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt);

		psz_flush_all_dirty_zones(NULL);

	}



	/* always return 0 as we had handled it on buffer */
@@ -756,9 +788,18 @@ static int notrace psz_pstore_write(struct pstore_record *record) 
			record->reason == KMSG_DUMP_PANIC)

		atomic_set(&cxt->on_panic, 1);



	/*

	 * if on panic, do not write except panic records

	 * Fix case that panic_write prints log which wakes up console backend.

	 */

	if (is_on_panic() && record->type != PSTORE_TYPE_DMESG)

		return -EBUSY;



	switch (record->type) {

	case PSTORE_TYPE_DMESG:

		return psz_kmsg_write(cxt, record);

	case PSTORE_TYPE_CONSOLE:

		return psz_record_write(cxt->cpsz, record);

	case PSTORE_TYPE_PMSG:

		return psz_record_write(cxt->ppsz, record);

	default:
@@ -783,6 +824,13 @@ static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) 
			return zone;

	}



	if (cxt->console_read_cnt == 0) {

		cxt->console_read_cnt++;

		zone = cxt->cpsz;

		if (psz_old_ok(zone))

			return zone;

	}



	return NULL;

}
@@ -893,6 +941,8 @@ static ssize_t psz_pstore_read(struct pstore_record *record) 
		readop = psz_kmsg_read;

		record->id = cxt->kmsg_read_cnt - 1;

		break;

	case PSTORE_TYPE_CONSOLE:

		fallthrough;

	case PSTORE_TYPE_PMSG:

		readop = psz_record_read;

		break;
@@ -953,6 +1003,8 @@ static void psz_free_all_zones(struct psz_context *cxt) 
		psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt);

	if (cxt->ppsz)

		psz_free_zone(&cxt->ppsz);

	if (cxt->cpsz)

		psz_free_zone(&cxt->cpsz);

}



static struct pstore_zone *psz_init_zone(enum pstore_type_id type,
@@ -1054,6 +1106,15 @@ static int psz_alloc_zones(struct psz_context *cxt) 
		goto free_out;

	}



	off_size += info->console_size;

	cxt->cpsz = psz_init_zone(PSTORE_TYPE_CONSOLE, &off,

			info->console_size);

	if (IS_ERR(cxt->cpsz)) {

		err = PTR_ERR(cxt->cpsz);

		cxt->cpsz = NULL;

		goto free_out;

	}



	cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off,

			info->total_size - off_size,

			info->kmsg_size, &cxt->kmsg_max_cnt);
@@ -1088,7 +1149,7 @@ int register_pstore_zone(struct pstore_zone_info *info) 
		return -EINVAL;

	}



	if (!info->kmsg_size && !info->pmsg_size) {

	if (!info->kmsg_size && !info->pmsg_size && !info->console_size) {

		pr_warn("at least one record size must be non-zero\n");

		return -EINVAL;

	}
@@ -1111,6 +1172,7 @@ int register_pstore_zone(struct pstore_zone_info *info) 
	check_size(total_size, 4096);

	check_size(kmsg_size, SECTOR_SIZE);

	check_size(pmsg_size, SECTOR_SIZE);

	check_size(console_size, SECTOR_SIZE);



#undef check_size
@@ -1137,6 +1199,7 @@ int register_pstore_zone(struct pstore_zone_info *info) 
	pr_debug("\ttotal size : %ld Bytes\n", info->total_size);

	pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size);

	pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size);

	pr_debug("\tconsole size : %ld Bytes\n", info->console_size);



	err = psz_alloc_zones(cxt);

	if (err) {
@@ -1170,6 +1233,10 @@ int register_pstore_zone(struct pstore_zone_info *info) 
		cxt->pstore.flags |= PSTORE_FLAGS_PMSG;

		pr_cont(" pmsg");

	}

	if (info->console_size) {

		cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;

		pr_cont(" console");

	}

	pr_cont("\n");



	err = pstore_register(&cxt->pstore);
@@ -1211,6 +1278,10 @@ void unregister_pstore_zone(struct pstore_zone_info *info) 
	/* Stop incoming writes from pstore. */

	pstore_unregister(&cxt->pstore);



	/* Flush any pending writes. */

	psz_flush_all_dirty_zones(NULL);

	flush_delayed_work(&psz_cleaner);



	/* Clean up allocations. */

	kfree(cxt->pstore.buf);

	cxt->pstore.buf = NULL;

include/linux/pstore_zone.h

+3 −1
Original line number Diff line number Diff line
@@ -18,11 +18,12 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); 
 *		it must be multiple of SECTOR_SIZE(512 Bytes).

 * @max_reason: Maximum kmsg dump reason to store.

 * @pmsg_size:	The size of pmsg zone which is the same as @kmsg_size.

 * @console_size:The size of console zone which is the same as @kmsg_size.

 * @read:	The general read operation. Both of the function parameters

 *		@size and @offset are relative value to storage.

 *		On success, the number of bytes should be returned, others

 *		means error.

 * @write:	The same as @read.

 * @write:	The same as @read, but -EBUSY means try to write again later.

 * @panic_write:The write operation only used for panic case. It's optional

 *		if you do not care panic log. The parameters and return value

 *		are the same as @read.
@@ -35,6 +36,7 @@ struct pstore_zone_info { 
	unsigned long kmsg_size;

	int max_reason;

	unsigned long pmsg_size;

	unsigned long console_size;

	pstore_zone_read_op read;

	pstore_zone_write_op write;

	pstore_zone_write_op panic_write;