Commit 0dc06826 authored by WeiXiong Liao's avatar WeiXiong Liao Committed by Kees Cook

pstore/zone,blk: Add support for pmsg frontend

Add pmsg support to pstore/blk (through pstore/zone). To enable, pmsg_size
must be greater than 0 and a multiple of 4096.
Signed-off-by: default avatarWeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-4-keescook@chromium.org/Co-developed-by: default avatarColin Ian King <colin.king@canonical.com>
Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/lkml/20200512171932.222102-1-colin.king@canonical.comCo-developed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 17639f67
......@@ -224,3 +224,15 @@ config PSTORE_BLK_MAX_REASON
NOTE that, both Kconfig and module parameters can configure
pstore/blk, but module parameters have priority over Kconfig.
config PSTORE_BLK_PMSG_SIZE
int "Size in Kbytes of pmsg to store"
depends on PSTORE_BLK
depends on PSTORE_PMSG
default 64
help
This just sets size of pmsg (pmsg_size) for 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.
......@@ -27,6 +27,14 @@ module_param(max_reason, int, 0400);
MODULE_PARM_DESC(max_reason,
"maximum reason for kmsg dump (default 2: Oops and Panic)");
#if IS_ENABLED(CONFIG_PSTORE_PMSG)
static long pmsg_size = CONFIG_PSTORE_BLK_PMSG_SIZE;
#else
static long pmsg_size = -1;
#endif
module_param(pmsg_size, long, 0400);
MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes");
/*
* blkdev - the block device to use for pstore storage
*
......@@ -133,6 +141,7 @@ 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);
#undef verify_size
pstore_zone_info->total_size = dev->total_size;
......
......@@ -27,12 +27,14 @@
*
* @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value)
* @datalen: length of data in @data
* @start: offset into @data where the beginning of the stored bytes begin
* @data: zone data.
*/
struct psz_buffer {
#define PSZ_SIG (0x43474244) /* DBGC */
uint32_t sig;
atomic_t datalen;
atomic_t start;
uint8_t data[];
};
......@@ -88,9 +90,11 @@ struct pstore_zone {
* struct psz_context - all about running state of pstore/zone
*
* @kpszs: kmsg dump storage zones
* @ppsz: pmsg 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
* @oops_counter: counter of oops dumps
* @panic_counter: counter of panic dumps
* @recovered: whether finished recovering data from storage
......@@ -101,9 +105,11 @@ struct pstore_zone {
*/
struct psz_context {
struct pstore_zone **kpszs;
struct pstore_zone *ppsz;
unsigned int kmsg_max_cnt;
unsigned int kmsg_read_cnt;
unsigned int kmsg_write_cnt;
unsigned int pmsg_read_cnt;
/*
* These counters should be calculated during recovery.
* It records the oops/panic times after crashes rather than boots.
......@@ -143,15 +149,20 @@ static inline int buffer_datalen(struct pstore_zone *zone)
return atomic_read(&zone->buffer->datalen);
}
static inline int buffer_start(struct pstore_zone *zone)
{
return atomic_read(&zone->buffer->start);
}
static inline bool is_on_panic(void)
{
return atomic_read(&pstore_zone_cxt.on_panic);
}
static ssize_t psz_zone_read(struct pstore_zone *zone, char *buf,
static ssize_t psz_zone_read_buffer(struct pstore_zone *zone, char *buf,
size_t len, unsigned long off)
{
if (!buf || !zone->buffer)
if (!buf || !zone || !zone->buffer)
return -EINVAL;
if (off > zone->buffer_size)
return -EINVAL;
......@@ -160,6 +171,18 @@ static ssize_t psz_zone_read(struct pstore_zone *zone, char *buf,
return len;
}
static int psz_zone_read_oldbuf(struct pstore_zone *zone, char *buf,
size_t len, unsigned long off)
{
if (!buf || !zone || !zone->oldbuf)
return -EINVAL;
if (off > zone->buffer_size)
return -EINVAL;
len = min_t(size_t, len, zone->buffer_size - off);
memcpy(buf, zone->oldbuf->data + off, len);
return 0;
}
static int psz_zone_write(struct pstore_zone *zone,
enum psz_flush_mode flush_mode, const char *buf,
size_t len, unsigned long off)
......@@ -415,6 +438,93 @@ static int psz_kmsg_recover(struct psz_context *cxt)
return ret;
}
static int psz_recover_zone(struct psz_context *cxt, struct pstore_zone *zone)
{
struct pstore_zone_info *info = cxt->pstore_zone_info;
struct psz_buffer *oldbuf, tmpbuf;
int ret = 0;
char *buf;
ssize_t rcnt, len, start, off;
if (!zone || zone->oldbuf)
return 0;
if (is_on_panic()) {
/* save data as much as possible */
psz_flush_dirty_zone(zone);
return 0;
}
if (unlikely(!info->read))
return -EINVAL;
len = sizeof(struct psz_buffer);
rcnt = info->read((char *)&tmpbuf, len, zone->off);
if (rcnt != len) {
pr_debug("read zone %s failed\n", zone->name);
return (int)rcnt < 0 ? (int)rcnt : -EIO;
}
if (tmpbuf.sig != zone->buffer->sig) {
pr_debug("no valid data in zone %s\n", zone->name);
return 0;
}
if (zone->buffer_size < atomic_read(&tmpbuf.datalen) ||
zone->buffer_size < atomic_read(&tmpbuf.start)) {
pr_info("found overtop zone: %s: off %lld, size %zu\n",
zone->name, zone->off, zone->buffer_size);
/* just keep going */
return 0;
}
if (!atomic_read(&tmpbuf.datalen)) {
pr_debug("found erased zone: %s: off %lld, size %zu, datalen %d\n",
zone->name, zone->off, zone->buffer_size,
atomic_read(&tmpbuf.datalen));
return 0;
}
pr_debug("found nice zone: %s: off %lld, size %zu, datalen %d\n",
zone->name, zone->off, zone->buffer_size,
atomic_read(&tmpbuf.datalen));
len = atomic_read(&tmpbuf.datalen) + sizeof(*oldbuf);
oldbuf = kzalloc(len, GFP_KERNEL);
if (!oldbuf)
return -ENOMEM;
memcpy(oldbuf, &tmpbuf, sizeof(*oldbuf));
buf = (char *)oldbuf + sizeof(*oldbuf);
len = atomic_read(&oldbuf->datalen);
start = atomic_read(&oldbuf->start);
off = zone->off + sizeof(*oldbuf);
/* get part of data */
rcnt = info->read(buf, len - start, off + start);
if (rcnt != len - start) {
pr_err("read zone %s failed\n", zone->name);
ret = (int)rcnt < 0 ? (int)rcnt : -EIO;
goto free_oldbuf;
}
/* get the rest of data */
rcnt = info->read(buf + len - start, start, off);
if (rcnt != start) {
pr_err("read zone %s failed\n", zone->name);
ret = (int)rcnt < 0 ? (int)rcnt : -EIO;
goto free_oldbuf;
}
zone->oldbuf = oldbuf;
psz_flush_dirty_zone(zone);
return 0;
free_oldbuf:
kfree(oldbuf);
return ret;
}
/**
* psz_recovery() - recover data from storage
* @cxt: the context of pstore/zone
......@@ -431,7 +541,12 @@ static inline int psz_recovery(struct psz_context *cxt)
return 0;
ret = psz_kmsg_recover(cxt);
if (ret)
goto out;
ret = psz_recover_zone(cxt, cxt->ppsz);
out:
if (unlikely(ret))
pr_err("recover failed\n");
else {
......@@ -446,9 +561,17 @@ static int psz_pstore_open(struct pstore_info *psi)
struct psz_context *cxt = psi->data;
cxt->kmsg_read_cnt = 0;
cxt->pmsg_read_cnt = 0;
return 0;
}
static inline bool psz_old_ok(struct pstore_zone *zone)
{
if (zone && zone->oldbuf && atomic_read(&zone->oldbuf->datalen))
return true;
return false;
}
static inline bool psz_ok(struct pstore_zone *zone)
{
if (zone && zone->buffer && buffer_datalen(zone))
......@@ -473,6 +596,25 @@ static inline int psz_kmsg_erase(struct psz_context *cxt,
return psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
}
static inline int psz_record_erase(struct psz_context *cxt,
struct pstore_zone *zone)
{
if (unlikely(!psz_old_ok(zone)))
return 0;
kfree(zone->oldbuf);
zone->oldbuf = NULL;
/*
* if there are new data in zone buffer, that means the old data
* are already invalid. It is no need to flush 0 (erase) to
* block device.
*/
if (!buffer_datalen(zone))
return psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
psz_flush_dirty_zone(zone);
return 0;
}
static int psz_pstore_erase(struct pstore_record *record)
{
struct psz_context *cxt = record->psi->data;
......@@ -482,6 +624,8 @@ static int psz_pstore_erase(struct pstore_record *record)
if (record->id >= cxt->kmsg_max_cnt)
return -EINVAL;
return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record);
case PSTORE_TYPE_PMSG:
return psz_record_erase(cxt, cxt->ppsz);
default:
return -EINVAL;
}
......@@ -555,6 +699,55 @@ static int notrace psz_kmsg_write(struct psz_context *cxt,
return 0;
}
static int notrace psz_record_write(struct pstore_zone *zone,
struct pstore_record *record)
{
size_t start, rem;
bool is_full_data = false;
char *buf;
int cnt;
if (!zone || !record)
return -ENOSPC;
if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size)
is_full_data = true;
cnt = record->size;
buf = record->buf;
if (unlikely(cnt > zone->buffer_size)) {
buf += cnt - zone->buffer_size;
cnt = zone->buffer_size;
}
start = buffer_start(zone);
rem = zone->buffer_size - start;
if (unlikely(rem < cnt)) {
psz_zone_write(zone, FLUSH_PART, buf, rem, start);
buf += rem;
cnt -= rem;
start = 0;
is_full_data = true;
}
atomic_set(&zone->buffer->start, cnt + start);
psz_zone_write(zone, FLUSH_PART, buf, cnt, start);
/**
* psz_zone_write will set datalen as start + cnt.
* It work if actual data length lesser than buffer size.
* If data length greater than buffer size, pmsg will rewrite to
* beginning of zone, which make buffer->datalen wrongly.
* So we should reset datalen as buffer size once actual data length
* greater than buffer size.
*/
if (is_full_data) {
atomic_set(&zone->buffer->datalen, zone->buffer_size);
psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
}
return 0;
}
static int notrace psz_pstore_write(struct pstore_record *record)
{
struct psz_context *cxt = record->psi->data;
......@@ -566,6 +759,8 @@ static int notrace psz_pstore_write(struct pstore_record *record)
switch (record->type) {
case PSTORE_TYPE_DMESG:
return psz_kmsg_write(cxt, record);
case PSTORE_TYPE_PMSG:
return psz_record_write(cxt->ppsz, record);
default:
return -EINVAL;
}
......@@ -581,6 +776,13 @@ static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt)
return zone;
}
if (cxt->pmsg_read_cnt == 0) {
cxt->pmsg_read_cnt++;
zone = cxt->ppsz;
if (psz_old_ok(zone))
return zone;
}
return NULL;
}
......@@ -631,7 +833,7 @@ static ssize_t psz_kmsg_read(struct pstore_zone *zone,
return -ENOMEM;
}
size = psz_zone_read(zone, record->buf + hlen, size,
size = psz_zone_read_buffer(zone, record->buf + hlen, size,
sizeof(struct psz_kmsg_header));
if (unlikely(size < 0)) {
kfree(record->buf);
......@@ -641,6 +843,32 @@ static ssize_t psz_kmsg_read(struct pstore_zone *zone,
return size + hlen;
}
static ssize_t psz_record_read(struct pstore_zone *zone,
struct pstore_record *record)
{
size_t len;
struct psz_buffer *buf;
if (!zone || !record)
return -ENOSPC;
buf = (struct psz_buffer *)zone->oldbuf;
if (!buf)
return -ENOMSG;
len = atomic_read(&buf->datalen);
record->buf = kmalloc(len, GFP_KERNEL);
if (!record->buf)
return -ENOMEM;
if (unlikely(psz_zone_read_oldbuf(zone, record->buf, len, 0))) {
kfree(record->buf);
return -ENOMSG;
}
return len;
}
static ssize_t psz_pstore_read(struct pstore_record *record)
{
struct psz_context *cxt = record->psi->data;
......@@ -665,6 +893,9 @@ 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_PMSG:
readop = psz_record_read;
break;
default:
goto next_zone;
}
......@@ -720,6 +951,8 @@ static void psz_free_all_zones(struct psz_context *cxt)
{
if (cxt->kpszs)
psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt);
if (cxt->ppsz)
psz_free_zone(&cxt->ppsz);
}
static struct pstore_zone *psz_init_zone(enum pstore_type_id type,
......@@ -753,8 +986,10 @@ static struct pstore_zone *psz_init_zone(enum pstore_type_id type,
zone->type = type;
zone->buffer_size = size - sizeof(struct psz_buffer);
zone->buffer->sig = type ^ PSZ_SIG;
zone->oldbuf = NULL;
atomic_set(&zone->dirty, 0);
atomic_set(&zone->buffer->datalen, 0);
atomic_set(&zone->buffer->start, 0);
*off += size;
......@@ -809,19 +1044,28 @@ static int psz_alloc_zones(struct psz_context *cxt)
struct pstore_zone_info *info = cxt->pstore_zone_info;
loff_t off = 0;
int err;
size_t size;
size_t off_size = 0;
off_size += info->pmsg_size;
cxt->ppsz = psz_init_zone(PSTORE_TYPE_PMSG, &off, info->pmsg_size);
if (IS_ERR(cxt->ppsz)) {
err = PTR_ERR(cxt->ppsz);
cxt->ppsz = NULL;
goto free_out;
}
size = info->total_size;
cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, size,
cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off,
info->total_size - off_size,
info->kmsg_size, &cxt->kmsg_max_cnt);
if (IS_ERR(cxt->kpszs)) {
err = PTR_ERR(cxt->kpszs);
cxt->kpszs = NULL;
goto fail_out;
goto free_out;
}
return 0;
fail_out:
free_out:
psz_free_all_zones(cxt);
return err;
}
......@@ -844,7 +1088,7 @@ int register_pstore_zone(struct pstore_zone_info *info)
return -EINVAL;
}
if (!info->kmsg_size) {
if (!info->kmsg_size && !info->pmsg_size) {
pr_warn("at least one record size must be non-zero\n");
return -EINVAL;
}
......@@ -866,6 +1110,7 @@ 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);
#undef check_size
......@@ -891,6 +1136,7 @@ int register_pstore_zone(struct pstore_zone_info *info)
pr_debug("register %s with properties:\n", info->name);
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);
err = psz_alloc_zones(cxt);
if (err) {
......@@ -920,6 +1166,10 @@ int register_pstore_zone(struct pstore_zone_info *info)
pr_cont(",panic_write");
pr_cont(")");
}
if (info->pmsg_size) {
cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
pr_cont(" pmsg");
}
pr_cont("\n");
err = pstore_register(&cxt->pstore);
......
......@@ -17,6 +17,7 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t);
* @kmsg_size: The size of oops/panic zone. Zero means disabled, otherwise,
* 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.
* @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
......@@ -33,6 +34,7 @@ struct pstore_zone_info {
unsigned long total_size;
unsigned long kmsg_size;
int max_reason;
unsigned long pmsg_size;
pstore_zone_read_op read;
pstore_zone_write_op write;
pstore_zone_write_op panic_write;
......
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