1 // SPDX-License-Identifier: GPL-2.0-only
3  * Persistent Storage - platform driver interface parts.
5  * Copyright (C) 2007-2008 Google, Inc.
39  * We defer making "oops" entries appear in pstore - see
43 static int pstore_update_ms = -1;
46 		 "(default is -1, which means runtime updates are disabled; "
57 	"powerpc-ofw",
58 	"powerpc-common",
60 	"powerpc-opal",
81 MODULE_PARM_DESC(backend, "specific backend to use");
90 MODULE_PARM_DESC(compress, "compression to use");
273 		return -EINVAL;  in pstore_compress()
290 	/* Skip if not built-in or compression backend not selected yet. */  in allocate_buf_for_compression()
298 	if (!crypto_has_comp(zbackend->name, 0, 0)) {  in allocate_buf_for_compression()
299 		pr_err("Unknown compression: %s\n", zbackend->name);  in allocate_buf_for_compression()
303 	size = zbackend->zbufsize(psinfo->bufsize);  in allocate_buf_for_compression()
306 		       zbackend->name, size);  in allocate_buf_for_compression()
313 		       size, zbackend->name);  in allocate_buf_for_compression()
317 	ctx = crypto_alloc_comp(zbackend->name, 0, 0);  in allocate_buf_for_compression()
320 		pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,  in allocate_buf_for_compression()
325 	/* A non-NULL big_oops_buf indicates compression is available. */  in allocate_buf_for_compression()
330 	pr_info("Using crash dump compression: %s\n", zbackend->name);  in allocate_buf_for_compression()
349  * Copy the recent messages from big_oops_buf to psinfo->buf
358 	if (total_len > psinfo->bufsize) {  in copy_kmsg_to_buffer()
359 		diff = total_len - psinfo->bufsize + hsize;  in copy_kmsg_to_buffer()
360 		memcpy(psinfo->buf, big_oops_buf, hsize);  in copy_kmsg_to_buffer()
361 		memcpy(psinfo->buf + hsize, big_oops_buf + diff,  in copy_kmsg_to_buffer()
362 					psinfo->bufsize - hsize);  in copy_kmsg_to_buffer()
363 		total_len = psinfo->bufsize;  in copy_kmsg_to_buffer()
365 		memcpy(psinfo->buf, big_oops_buf, total_len);  in copy_kmsg_to_buffer()
375 	record->psi = psinfo;  in pstore_record_init()
378 	record->time = ns_to_timespec64(ktime_get_real_fast_ns());  in pstore_record_init()
395 	if (down_trylock(&psinfo->buf_lock)) {  in pstore_dump()
402 		if (down_interruptible(&psinfo->buf_lock)) {  in pstore_dump()
413 		int zipped_len = -1;  in pstore_dump()
422 		record.buf = psinfo->buf;  in pstore_dump()
428 			dst = psinfo->buf;  in pstore_dump()
429 			dst_size = psinfo->bufsize;  in pstore_dump()
435 		dst_size -= header_size;  in pstore_dump()
443 			zipped_len = pstore_compress(dst, psinfo->buf,  in pstore_dump()
445 						psinfo->bufsize);  in pstore_dump()
458 		ret = psinfo->write(&record);  in pstore_dump()
468 	up(&psinfo->buf_lock);  in pstore_dump()
501 	psinfo->write(&record);  in pstore_console_write()
506 	.index	= -1,
512 	strscpy(pstore_console.name, psinfo->name,  in pstore_register_console()
536 	if (record->buf)  in pstore_write_user_compat()
537 		return -EINVAL;  in pstore_write_user_compat()
539 	record->buf = memdup_user(buf, record->size);  in pstore_write_user_compat()
540 	if (IS_ERR(record->buf)) {  in pstore_write_user_compat()
541 		ret = PTR_ERR(record->buf);  in pstore_write_user_compat()
545 	ret = record->psi->write(record);  in pstore_write_user_compat()
547 	kfree(record->buf);  in pstore_write_user_compat()
549 	record->buf = NULL;  in pstore_write_user_compat()
551 	return unlikely(ret < 0) ? ret : record->size;  in pstore_write_user_compat()
563 	if (backend && strcmp(backend, psi->name)) {  in pstore_register()
564 		pr_warn("ignoring unexpected backend '%s'\n", psi->name);  in pstore_register()
565 		return -EPERM;  in pstore_register()
569 	if (!psi->flags) {  in pstore_register()
571 			psi->name);  in pstore_register()
572 		return -EINVAL;  in pstore_register()
576 	if (!psi->read || !psi->write) {  in pstore_register()
578 			psi->name);  in pstore_register()
579 		return -EINVAL;  in pstore_register()
585 			psinfo->name, psi->name);  in pstore_register()
587 		return -EBUSY;  in pstore_register()
590 	if (!psi->write_user)  in pstore_register()
591 		psi->write_user = pstore_write_user_compat;  in pstore_register()
593 	mutex_init(&psinfo->read_mutex);  in pstore_register()
594 	sema_init(&psinfo->buf_lock, 1);  in pstore_register()
596 	if (psi->flags & PSTORE_FLAGS_DMESG)  in pstore_register()
601 	if (psi->flags & PSTORE_FLAGS_DMESG) {  in pstore_register()
602 		pstore_dumper.max_reason = psinfo->max_reason;  in pstore_register()
605 	if (psi->flags & PSTORE_FLAGS_CONSOLE)  in pstore_register()
607 	if (psi->flags & PSTORE_FLAGS_FTRACE)  in pstore_register()
609 	if (psi->flags & PSTORE_FLAGS_PMSG)  in pstore_register()
619 	backend = kstrdup(psi->name, GFP_KERNEL);  in pstore_register()
621 	pr_info("Registered %s as persistent store backend\n", psi->name);  in pstore_register()
643 	if (psi->flags & PSTORE_FLAGS_PMSG)  in pstore_unregister()
645 	if (psi->flags & PSTORE_FLAGS_FTRACE)  in pstore_unregister()
647 	if (psi->flags & PSTORE_FLAGS_CONSOLE)  in pstore_unregister()
649 	if (psi->flags & PSTORE_FLAGS_DMESG)  in pstore_unregister()
674 	if (!IS_ENABLED(CONFIG_PSTORE_COMPRESSION) || !record->compressed)  in decompress_record()
678 	if (record->type != PSTORE_TYPE_DMESG) {  in decompress_record()
679 		pr_warn("ignored compressed record type %d\n", record->type);  in decompress_record()
689 	/* Allocate enough space to hold max decompression and ECC. */  in decompress_record()
691 	workspace = kmalloc(unzipped_len + record->ecc_notice_size,  in decompress_record()
697 	ret = crypto_comp_decompress(tfm, record->buf, record->size,  in decompress_record()
705 	/* Append ECC notice to decompressed buffer. */  in decompress_record()
706 	memcpy(workspace + unzipped_len, record->buf + record->size,  in decompress_record()
707 	       record->ecc_notice_size);  in decompress_record()
709 	/* Copy decompressed contents into an minimum-sized allocation. */  in decompress_record()
710 	unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size,  in decompress_record()
717 	kfree(record->buf);  in decompress_record()
718 	record->buf = unzipped;  in decompress_record()
719 	record->size = unzipped_len;  in decompress_record()
720 	record->compressed = false;  in decompress_record()
725  * files in our filesystem.  Don't warn about -EEXIST errors
726  * when we are re-scanning the backing store looking to add new
738 	mutex_lock(&psi->read_mutex);  in pstore_get_backend_records()
739 	if (psi->open && psi->open(psi))  in pstore_get_backend_records()
747 	for (; stop_loop; stop_loop--) {  in pstore_get_backend_records()
758 		record->size = psi->read(record);  in pstore_get_backend_records()
761 		if (record->size <= 0) {  in pstore_get_backend_records()
770 			kfree(record->buf);  in pstore_get_backend_records()
772 			if (rc != -EEXIST || !quiet)  in pstore_get_backend_records()
776 	if (psi->close)  in pstore_get_backend_records()
777 		psi->close(psi);  in pstore_get_backend_records()
779 	mutex_unlock(&psi->read_mutex);  in pstore_get_backend_records()
783 			failed, psi->name);  in pstore_get_backend_records()
786 			psi->name);  in pstore_get_backend_records()
811 	for (step = zbackends; step->name; step++) {  in pstore_choose_compression()
812 		if (!strcmp(compress, step->name)) {  in pstore_choose_compression()