From 34327e9fd213414b35eb70aa512c4e39b2095907 Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:55:01 +0800 Subject: pstore/zone,blk: Add ftrace frontend support Support backend for ftrace. To enable ftrace backend, just make ftrace_size be greater than 0 and a multiple of 4096. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-6-keescook@chromium.org/ Co-developed-by: Colin Ian King Signed-off-by: Colin Ian King Link: https://lore.kernel.org/lkml/20200512170719.221514-1-colin.king@canonical.com Signed-off-by: Kees Cook --- fs/pstore/Kconfig | 12 ++++++ fs/pstore/blk.c | 9 +++++ fs/pstore/zone.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 134 insertions(+), 1 deletion(-) (limited to 'fs/pstore') diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 126aa6c3ecf2..c2237984b407 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -248,3 +248,15 @@ config PSTORE_BLK_CONSOLE_SIZE NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. + +config PSTORE_BLK_FTRACE_SIZE + int "Size in Kbytes of ftrace log to store" + depends on PSTORE_BLK + depends on PSTORE_FTRACE + default 64 + help + This just sets size of ftrace log (ftrace_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 082f6cdaf4bd..e0d95fb48428 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -43,6 +43,14 @@ static long console_size = -1; module_param(console_size, long, 0400); MODULE_PARM_DESC(console_size, "console size in kbytes"); +#if IS_ENABLED(CONFIG_PSTORE_FTRACE) +static long ftrace_size = CONFIG_PSTORE_BLK_FTRACE_SIZE; +#else +static long ftrace_size = -1; +#endif +module_param(ftrace_size, long, 0400); +MODULE_PARM_DESC(ftrace_size, "ftrace size in kbytes"); + /* * blkdev - the block device to use for pstore storage * @@ -152,6 +160,7 @@ 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); + verify_size(ftrace_size, 4096, dev->flags & PSTORE_FLAGS_FTRACE); #undef verify_size pstore_zone_info->total_size = dev->total_size; diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index ee0b64da410d..2d9f452360bb 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -92,11 +92,14 @@ struct pstore_zone { * @kpszs: kmsg dump storage zones * @ppsz: pmsg storage zone * @cpsz: console storage zone + * @fpszs: ftrace storage zones * @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 + * @ftrace_max_cnt: max count of @fpszs + * @ftrace_read_cnt: counter of max read ftrace zone * @oops_counter: counter of oops dumps * @panic_counter: counter of panic dumps * @recovered: whether finished recovering data from storage @@ -109,11 +112,14 @@ struct psz_context { struct pstore_zone **kpszs; struct pstore_zone *ppsz; struct pstore_zone *cpsz; + struct pstore_zone **fpszs; 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; + unsigned int ftrace_max_cnt; + unsigned int ftrace_read_cnt; /* * These counters should be calculated during recovery. * It records the oops/panic times after crashes rather than boots. @@ -314,6 +320,8 @@ static void psz_flush_all_dirty_zones(struct work_struct *work) ret |= psz_flush_dirty_zone(cxt->cpsz); if (cxt->kpszs) ret |= psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt); + if (cxt->fpszs) + ret |= psz_flush_dirty_zones(cxt->fpszs, cxt->ftrace_max_cnt); if (ret && cxt->pstore_zone_info) schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(1000)); } @@ -550,6 +558,31 @@ free_oldbuf: return ret; } +static int psz_recover_zones(struct psz_context *cxt, + struct pstore_zone **zones, unsigned int cnt) +{ + int ret; + unsigned int i; + struct pstore_zone *zone; + + if (!zones) + return 0; + + for (i = 0; i < cnt; i++) { + zone = zones[i]; + if (unlikely(!zone)) + continue; + ret = psz_recover_zone(cxt, zone); + if (ret) + goto recover_fail; + } + + return 0; +recover_fail: + pr_debug("recover %s[%u] failed\n", zone->name, i); + return ret; +} + /** * psz_recovery() - recover data from storage * @cxt: the context of pstore/zone @@ -574,6 +607,10 @@ static inline int psz_recovery(struct psz_context *cxt) goto out; ret = psz_recover_zone(cxt, cxt->cpsz); + if (ret) + goto out; + + ret = psz_recover_zones(cxt, cxt->fpszs, cxt->ftrace_max_cnt); out: if (unlikely(ret)) @@ -592,6 +629,7 @@ static int psz_pstore_open(struct pstore_info *psi) cxt->kmsg_read_cnt = 0; cxt->pmsg_read_cnt = 0; cxt->console_read_cnt = 0; + cxt->ftrace_read_cnt = 0; return 0; } @@ -658,6 +696,10 @@ static int psz_pstore_erase(struct pstore_record *record) return psz_record_erase(cxt, cxt->ppsz); case PSTORE_TYPE_CONSOLE: return psz_record_erase(cxt, cxt->cpsz); + case PSTORE_TYPE_FTRACE: + if (record->id >= cxt->ftrace_max_cnt) + return -EINVAL; + return psz_record_erase(cxt, cxt->fpszs[record->id]); default: return -EINVAL; } } @@ -802,6 +844,13 @@ static int notrace psz_pstore_write(struct pstore_record *record) return psz_record_write(cxt->cpsz, record); case PSTORE_TYPE_PMSG: return psz_record_write(cxt->ppsz, record); + case PSTORE_TYPE_FTRACE: { + int zonenum = smp_processor_id(); + + if (!cxt->fpszs) + return -ENOSPC; + return psz_record_write(cxt->fpszs[zonenum], record); + } default: return -EINVAL; } @@ -817,6 +866,14 @@ static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) return zone; } + if (cxt->ftrace_read_cnt < cxt->ftrace_max_cnt) + /* + * No need psz_old_ok(). Let psz_ftrace_read() do so for + * combination. psz_ftrace_read() should traverse over + * all zones in case of some zone without data. + */ + return cxt->fpszs[cxt->ftrace_read_cnt++]; + if (cxt->pmsg_read_cnt == 0) { cxt->pmsg_read_cnt++; zone = cxt->ppsz; @@ -891,6 +948,38 @@ static ssize_t psz_kmsg_read(struct pstore_zone *zone, return size + hlen; } +/* try to combine all ftrace zones */ +static ssize_t psz_ftrace_read(struct pstore_zone *zone, + struct pstore_record *record) +{ + struct psz_context *cxt; + struct psz_buffer *buf; + int ret; + + if (!zone || !record) + return -ENOSPC; + + if (!psz_old_ok(zone)) + goto out; + + buf = (struct psz_buffer *)zone->oldbuf; + if (!buf) + return -ENOMSG; + + ret = pstore_ftrace_combine_log(&record->buf, &record->size, + (char *)buf->data, atomic_read(&buf->datalen)); + if (unlikely(ret)) + return ret; + +out: + cxt = record->psi->data; + if (cxt->ftrace_read_cnt < cxt->ftrace_max_cnt) + /* then, read next ftrace zone */ + return -ENOMSG; + record->id = 0; + return record->size ? record->size : -ENOMSG; +} + static ssize_t psz_record_read(struct pstore_zone *zone, struct pstore_record *record) { @@ -941,6 +1030,9 @@ next_zone: readop = psz_kmsg_read; record->id = cxt->kmsg_read_cnt - 1; break; + case PSTORE_TYPE_FTRACE: + readop = psz_ftrace_read; + break; case PSTORE_TYPE_CONSOLE: fallthrough; case PSTORE_TYPE_PMSG: @@ -1005,6 +1097,8 @@ static void psz_free_all_zones(struct psz_context *cxt) psz_free_zone(&cxt->ppsz); if (cxt->cpsz) psz_free_zone(&cxt->cpsz); + if (cxt->fpszs) + psz_free_zones(&cxt->fpszs, &cxt->ftrace_max_cnt); } static struct pstore_zone *psz_init_zone(enum pstore_type_id type, @@ -1115,6 +1209,17 @@ static int psz_alloc_zones(struct psz_context *cxt) goto free_out; } + off_size += info->ftrace_size; + cxt->fpszs = psz_init_zones(PSTORE_TYPE_FTRACE, &off, + info->ftrace_size, + info->ftrace_size / nr_cpu_ids, + &cxt->ftrace_max_cnt); + if (IS_ERR(cxt->fpszs)) { + err = PTR_ERR(cxt->fpszs); + cxt->fpszs = 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); @@ -1149,7 +1254,8 @@ int register_pstore_zone(struct pstore_zone_info *info) return -EINVAL; } - if (!info->kmsg_size && !info->pmsg_size && !info->console_size) { + if (!info->kmsg_size && !info->pmsg_size && !info->console_size && + !info->ftrace_size) { pr_warn("at least one record size must be non-zero\n"); return -EINVAL; } @@ -1173,6 +1279,7 @@ int register_pstore_zone(struct pstore_zone_info *info) check_size(kmsg_size, SECTOR_SIZE); check_size(pmsg_size, SECTOR_SIZE); check_size(console_size, SECTOR_SIZE); + check_size(ftrace_size, SECTOR_SIZE); #undef check_size @@ -1200,6 +1307,7 @@ int register_pstore_zone(struct pstore_zone_info *info) 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); + pr_debug("\tftrace size : %ld Bytes\n", info->ftrace_size); err = psz_alloc_zones(cxt); if (err) { @@ -1237,6 +1345,10 @@ int register_pstore_zone(struct pstore_zone_info *info) cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; pr_cont(" console"); } + if (info->ftrace_size) { + cxt->pstore.flags |= PSTORE_FLAGS_FTRACE; + pr_cont(" ftrace"); + } pr_cont("\n"); err = pstore_register(&cxt->pstore); -- cgit v1.2.3