[mirror_ubuntu-bionic-kernel.git] / drivers / firmware / efi / efi-pstore.c

#include <linux/efi.h>
#include <linux/module.h>
#include <linux/pstore.h>
#include <linux/ucs2_string.h>

#define DUMP_NAME_LEN 52

static bool efivars_pstore_disable =
	IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);

module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);

#define PSTORE_EFI_ATTRIBUTES \
	(EFI_VARIABLE_NON_VOLATILE | \
	 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
	 EFI_VARIABLE_RUNTIME_ACCESS)

static int efi_pstore_open(struct pstore_info *psi)
{
	efivar_entry_iter_begin();
	psi->data = NULL;
	return 0;
}

static int efi_pstore_close(struct pstore_info *psi)
{
	efivar_entry_iter_end();
	psi->data = NULL;
	return 0;
}

struct pstore_read_data {
	u64 *id;
	enum pstore_type_id *type;
	int *count;
	struct timespec *timespec;
	char **buf;
};

static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
{
	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	struct pstore_read_data *cb_data = data;
	char name[DUMP_NAME_LEN];
	int i;
	int cnt;
	unsigned int part;
	unsigned long time, size;

	if (efi_guidcmp(entry->var.VendorGuid, vendor))
		return 0;

	for (i = 0; i < DUMP_NAME_LEN; i++)
		name[i] = entry->var.VariableName[i];

	if (sscanf(name, "dump-type%u-%u-%d-%lu",
		   cb_data->type, &part, &cnt, &time) == 4) {
		*cb_data->id = part;
		*cb_data->count = cnt;
		cb_data->timespec->tv_sec = time;
		cb_data->timespec->tv_nsec = 0;
	} else if (sscanf(name, "dump-type%u-%u-%lu",
			  cb_data->type, &part, &time) == 3) {
		/*
		 * Check if an old format,
		 * which doesn't support holding
		 * multiple logs, remains.
		 */
		*cb_data->id = part;
		*cb_data->count = 0;
		cb_data->timespec->tv_sec = time;
		cb_data->timespec->tv_nsec = 0;
	} else
		return 0;

	__efivar_entry_size(entry, &size);
	*cb_data->buf = kmalloc(size, GFP_KERNEL);
	if (*cb_data->buf == NULL)
		return -ENOMEM;
	memcpy(*cb_data->buf, entry->var.Data, size);
	return size;
}

static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
			       int *count, struct timespec *timespec,
			       char **buf, struct pstore_info *psi)
{
	struct pstore_read_data data;

	data.id = id;
	data.type = type;
	data.count = count;
	data.timespec = timespec;
	data.buf = buf;

	return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data,
				   (struct efivar_entry **)&psi->data);
}

static int efi_pstore_write(enum pstore_type_id type,
		enum kmsg_dump_reason reason, u64 *id,
		unsigned int part, int count, size_t size,
		struct pstore_info *psi)
{
	char name[DUMP_NAME_LEN];
	efi_char16_t efi_name[DUMP_NAME_LEN];
	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	int i, ret = 0;

	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
		get_seconds());

	for (i = 0; i < DUMP_NAME_LEN; i++)
		efi_name[i] = name[i];

	efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
			      !pstore_cannot_block_path(reason),
			      size, psi->buf);

	if (reason == KMSG_DUMP_OOPS)
		efivar_run_worker();

	*id = part;
	return ret;
};

struct pstore_erase_data {
	u64 id;
	enum pstore_type_id type;
	int count;
	struct timespec time;
	efi_char16_t *name;
};

/*
 * Clean up an entry with the same name
 */
static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
{
	struct pstore_erase_data *ed = data;
	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	efi_char16_t efi_name_old[DUMP_NAME_LEN];
	efi_char16_t *efi_name = ed->name;
	unsigned long ucs2_len = ucs2_strlen(ed->name);
	char name_old[DUMP_NAME_LEN];
	int i;

	if (efi_guidcmp(entry->var.VendorGuid, vendor))
		return 0;

	if (ucs2_strncmp(entry->var.VariableName,
			  efi_name, (size_t)ucs2_len)) {
		/*
		 * Check if an old format, which doesn't support
		 * holding multiple logs, remains.
		 */
		sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
			(unsigned int)ed->id, ed->time.tv_sec);

		for (i = 0; i < DUMP_NAME_LEN; i++)
			efi_name_old[i] = name_old[i];

		if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
				  ucs2_strlen(efi_name_old)))
			return 0;
	}

	/* found */
	__efivar_entry_delete(entry);
	return 1;
}

static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
			    struct timespec time, struct pstore_info *psi)
{
	struct pstore_erase_data edata;
	struct efivar_entry *entry;
	char name[DUMP_NAME_LEN];
	efi_char16_t efi_name[DUMP_NAME_LEN];
	int found, i;

	sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
		time.tv_sec);

	for (i = 0; i < DUMP_NAME_LEN; i++)
		efi_name[i] = name[i];

	edata.id = id;
	edata.type = type;
	edata.count = count;
	edata.time = time;
	edata.name = efi_name;

	efivar_entry_iter_begin();
	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
	efivar_entry_iter_end();

	if (found)
		efivar_unregister(entry);

	return 0;
}

static struct pstore_info efi_pstore_info = {
	.owner		= THIS_MODULE,
	.name		= "efi",
	.open		= efi_pstore_open,
	.close		= efi_pstore_close,
	.read		= efi_pstore_read,
	.write		= efi_pstore_write,
	.erase		= efi_pstore_erase,
};

static __init int efivars_pstore_init(void)
{
	if (!efi_enabled(EFI_RUNTIME_SERVICES))
		return 0;

	if (!efivars_kobject())
		return 0;

	if (efivars_pstore_disable)
		return 0;

	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
	if (!efi_pstore_info.buf)
		return -ENOMEM;

	efi_pstore_info.bufsize = 1024;
	spin_lock_init(&efi_pstore_info.buf_lock);

	pstore_register(&efi_pstore_info);

	return 0;
}

static __exit void efivars_pstore_exit(void)
{
}

module_init(efivars_pstore_init);
module_exit(efivars_pstore_exit);

MODULE_DESCRIPTION("EFI variable backend for pstore");
MODULE_LICENSE("GPL");
Commit	Line	Data
04851772 MF	1	#include <linux/efi.h>
	2	#include <linux/module.h>
	3	#include <linux/pstore.h>
a614e192	4	#include <linux/ucs2_string.h>
04851772 MF	5
	6	#define DUMP_NAME_LEN 52
	7
	8	static bool efivars_pstore_disable =
	9	IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
	10
	11	module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
	12
	13	#define PSTORE_EFI_ATTRIBUTES \
	14	(EFI_VARIABLE_NON_VOLATILE \| \
	15	EFI_VARIABLE_BOOTSERVICE_ACCESS \| \
	16	EFI_VARIABLE_RUNTIME_ACCESS)
	17
	18	static int efi_pstore_open(struct pstore_info *psi)
	19	{
	20	efivar_entry_iter_begin();
	21	psi->data = NULL;
	22	return 0;
	23	}
	24
	25	static int efi_pstore_close(struct pstore_info *psi)
	26	{
	27	efivar_entry_iter_end();
	28	psi->data = NULL;
	29	return 0;
	30	}
	31
	32	struct pstore_read_data {
	33	u64 *id;
	34	enum pstore_type_id *type;
	35	int *count;
	36	struct timespec *timespec;
	37	char **buf;
	38	};
	39
	40	static int efi_pstore_read_func(struct efivar_entry entry, void data)
	41	{
	42	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	43	struct pstore_read_data *cb_data = data;
	44	char name[DUMP_NAME_LEN];
	45	int i;
	46	int cnt;
	47	unsigned int part;
	48	unsigned long time, size;
	49
	50	if (efi_guidcmp(entry->var.VendorGuid, vendor))
	51	return 0;
	52
	53	for (i = 0; i < DUMP_NAME_LEN; i++)
	54	name[i] = entry->var.VariableName[i];
	55
	56	if (sscanf(name, "dump-type%u-%u-%d-%lu",
	57	cb_data->type, &part, &cnt, &time) == 4) {
	58	*cb_data->id = part;
	59	*cb_data->count = cnt;
	60	cb_data->timespec->tv_sec = time;
	61	cb_data->timespec->tv_nsec = 0;
	62	} else if (sscanf(name, "dump-type%u-%u-%lu",
	63	cb_data->type, &part, &time) == 3) {
	64	/*
	65	* Check if an old format,
	66	* which doesn't support holding
	67	* multiple logs, remains.
	68	*/
69	*cb_data->id = part;
70	*cb_data->count = 0;
71	cb_data->timespec->tv_sec = time;
72	cb_data->timespec->tv_nsec = 0;
73	} else
74	return 0;
75
76	__efivar_entry_size(entry, &size);
77	*cb_data->buf = kmalloc(size, GFP_KERNEL);
78	if (*cb_data->buf == NULL)
79	return -ENOMEM;
80	memcpy(*cb_data->buf, entry->var.Data, size);
81	return size;
82	}
83
84	static ssize_t efi_pstore_read(u64 id, enum pstore_type_id type,
85	int count, struct timespec timespec,
86	char *buf, struct pstore_info psi)
87	{
88	struct pstore_read_data data;
89
90	data.id = id;
91	data.type = type;
92	data.count = count;
93	data.timespec = timespec;
94	data.buf = buf;
95
96	return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data,
97	(struct efivar_entry **)&psi->data);
98	}
99
100	static int efi_pstore_write(enum pstore_type_id type,
101	enum kmsg_dump_reason reason, u64 *id,
102	unsigned int part, int count, size_t size,
103	struct pstore_info *psi)
104	{
105	char name[DUMP_NAME_LEN];
106	efi_char16_t efi_name[DUMP_NAME_LEN];
107	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
108	int i, ret = 0;
109
110	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
111	get_seconds());
112
113	for (i = 0; i < DUMP_NAME_LEN; i++)
114	efi_name[i] = name[i];
115
116	efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
117	!pstore_cannot_block_path(reason),
118	size, psi->buf);
119
120	if (reason == KMSG_DUMP_OOPS)
121	efivar_run_worker();
122
123	*id = part;
124	return ret;
125	};
126
127	struct pstore_erase_data {
128	u64 id;
129	enum pstore_type_id type;
130	int count;
131	struct timespec time;
132	efi_char16_t *name;
133	};
134
135	/*
136	* Clean up an entry with the same name
137	*/
138	static int efi_pstore_erase_func(struct efivar_entry entry, void data)
139	{
140	struct pstore_erase_data *ed = data;
141	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
142	efi_char16_t efi_name_old[DUMP_NAME_LEN];
143	efi_char16_t *efi_name = ed->name;
a614e192	144	unsigned long ucs2_len = ucs2_strlen(ed->name);
04851772 MF	145	char name_old[DUMP_NAME_LEN];
	146	int i;
	147
	148	if (efi_guidcmp(entry->var.VendorGuid, vendor))
	149	return 0;
	150
a614e192 MF	151	if (ucs2_strncmp(entry->var.VariableName,
a614e192 MF	152	efi_name, (size_t)ucs2_len)) {
04851772 MF	153	/*
	154	* Check if an old format, which doesn't support
	155	* holding multiple logs, remains.
	156	*/
	157	sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
	158	(unsigned int)ed->id, ed->time.tv_sec);
	159
	160	for (i = 0; i < DUMP_NAME_LEN; i++)
	161	efi_name_old[i] = name_old[i];
	162
a614e192 MF	163	if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
a614e192 MF	164	ucs2_strlen(efi_name_old)))
04851772 MF	165	return 0;
	166	}
	167
	168	/* found */
	169	__efivar_entry_delete(entry);
	170	return 1;
	171	}
	172
	173	static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
	174	struct timespec time, struct pstore_info *psi)
	175	{
	176	struct pstore_erase_data edata;
	177	struct efivar_entry *entry;
	178	char name[DUMP_NAME_LEN];
	179	efi_char16_t efi_name[DUMP_NAME_LEN];
	180	int found, i;
	181
	182	sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
	183	time.tv_sec);
	184
	185	for (i = 0; i < DUMP_NAME_LEN; i++)
	186	efi_name[i] = name[i];
	187
	188	edata.id = id;
	189	edata.type = type;
	190	edata.count = count;
	191	edata.time = time;
	192	edata.name = efi_name;
	193
	194	efivar_entry_iter_begin();
	195	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
	196	efivar_entry_iter_end();
	197
	198	if (found)
	199	efivar_unregister(entry);
	200
	201	return 0;
	202	}
	203
	204	static struct pstore_info efi_pstore_info = {
	205	.owner = THIS_MODULE,
	206	.name = "efi",
	207	.open = efi_pstore_open,
	208	.close = efi_pstore_close,
	209	.read = efi_pstore_read,
	210	.write = efi_pstore_write,
	211	.erase = efi_pstore_erase,
	212	};
	213
	214	static __init int efivars_pstore_init(void)
	215	{
	216	if (!efi_enabled(EFI_RUNTIME_SERVICES))
	217	return 0;
	218
	219	if (!efivars_kobject())
	220	return 0;
	221
	222	if (efivars_pstore_disable)
	223	return 0;
	224
	225	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
	226	if (!efi_pstore_info.buf)
	227	return -ENOMEM;
	228
229	efi_pstore_info.bufsize = 1024;
230	spin_lock_init(&efi_pstore_info.buf_lock);
231
232	pstore_register(&efi_pstore_info);
233
234	return 0;
235	}
236
237	static __exit void efivars_pstore_exit(void)
238	{
239	}
240
241	module_init(efivars_pstore_init);
242	module_exit(efivars_pstore_exit);
243
244	MODULE_DESCRIPTION("EFI variable backend for pstore");
245	MODULE_LICENSE("GPL");