From: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx> 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: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/1585126506-18635-5-git-send-email-liaoweixiong@xxxxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- fs/pstore/Kconfig | 12 ++ fs/pstore/blk.c | 9 ++ fs/pstore/zone.c | 265 ++++++++++++++++++++++++++++++++++-- include/linux/pstore_zone.h | 2 + 4 files changed, 279 insertions(+), 9 deletions(-) diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 958bec75f907..ef01c48f0ff7 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -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. diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 6490c60af0dc..e3fa29988b0f 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -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; diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index 20fa52385c78..fe6fde96d722 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -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 @@ -434,6 +544,10 @@ static inline int psz_recovery(struct psz_context *cxt) if (ret) goto recover_fail; + ret = psz_recover_zone(cxt, cxt->ppsz); + if (ret) + goto recover_fail; + pr_debug("recover end!\n"); atomic_set(&cxt->recovered, 1); return 0; @@ -448,9 +562,17 @@ 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)) @@ -475,6 +597,25 @@ 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; @@ -484,6 +625,8 @@ 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; } @@ -557,6 +700,53 @@ 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; + int cnt = record->size; + bool is_full_data = false; + char *buf = record->buf; + + if (!zone || !record) + return -ENOSPC; + + if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size) + is_full_data = true; + + 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; @@ -568,6 +758,8 @@ 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; } @@ -583,6 +775,13 @@ 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; } @@ -633,7 +832,7 @@ 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); @@ -643,6 +842,32 @@ 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; @@ -667,6 +892,9 @@ 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; } @@ -722,6 +950,8 @@ 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, @@ -755,8 +985,10 @@ 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; @@ -811,19 +1043,28 @@ 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; } @@ -846,7 +1087,7 @@ 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; } @@ -868,6 +1109,7 @@ 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 @@ -893,6 +1135,7 @@ 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) { @@ -922,6 +1165,10 @@ 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); diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index eb005d9ae40c..29c367a3bd80 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -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; -- 2.20.1
