From: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx> Support backend for console. To enable console backend, just make console_size be greater than 0 and a multiple of 4096. Signed-off-by: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/1585126506-18635-6-git-send-email-liaoweixiong@xxxxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- fs/pstore/Kconfig | 18 +++++++-- fs/pstore/blk.c | 12 +++++- fs/pstore/zone.c | 81 ++++++++++++++++++++++++++++++++++--- include/linux/pstore_zone.h | 4 +- 4 files changed, 105 insertions(+), 10 deletions(-) diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index ef01c48f0ff7..126aa6c3ecf2 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -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. diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index e3fa29988b0f..0b88c0bcd36c 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -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; diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index fe6fde96d722..33c99dc5f980 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -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; @@ -548,6 +573,10 @@ static inline int psz_recovery(struct psz_context *cxt) if (ret) goto recover_fail; + ret = psz_recover_zone(cxt, cxt->cpsz); + if (ret) + goto recover_fail; + pr_debug("recover end!\n"); atomic_set(&cxt->recovered, 1); return 0; @@ -563,6 +592,7 @@ 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; } @@ -627,8 +657,9 @@ 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; } } @@ -691,9 +722,10 @@ 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 */ @@ -755,9 +787,18 @@ 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: @@ -782,6 +823,13 @@ 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; } @@ -892,6 +940,8 @@ 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; @@ -952,6 +1002,8 @@ 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, @@ -1053,6 +1105,15 @@ 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); @@ -1087,7 +1148,7 @@ 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; } @@ -1110,6 +1171,7 @@ 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 @@ -1136,6 +1198,7 @@ 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) { @@ -1169,6 +1232,10 @@ 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); @@ -1210,6 +1277,10 @@ 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; diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 29c367a3bd80..904ee67f4ba2 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -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; -- 2.20.1
