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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id i124sm7055500pfg.14.2020.03.18.11.16.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Mar 2020 11:16:57 -0700 (PDT) Date: Wed, 18 Mar 2020 11:16:56 -0700 From: Kees Cook To: WeiXiong Liao Cc: Anton Vorontsov , Colin Cross , Tony Luck , Jonathan Corbet , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Mauro Carvalho Chehab , "David S. Miller" , Rob Herring , Greg Kroah-Hartman , Jonathan Cameron , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org Subject: Re: [PATCH v2 04/11] pstore/blk: blkoops: support console recorder Message-ID: <202003181113.46DD4C142F@keescook> References: <1581078355-19647-1-git-send-email-liaoweixiong@allwinnertech.com> <1581078355-19647-5-git-send-email-liaoweixiong@allwinnertech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1581078355-19647-5-git-send-email-liaoweixiong@allwinnertech.com> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, Feb 07, 2020 at 08:25:48PM +0800, WeiXiong Liao wrote: > Support recorder for console. To enable console recorder, just make > console_size be greater than 0 and a multiple of 4096. > > Signed-off-by: WeiXiong Liao > --- > fs/pstore/Kconfig | 12 ++++++ > fs/pstore/blkoops.c | 11 +++++ > fs/pstore/blkzone.c | 101 ++++++++++++++++++++++++++++++++++----------- > include/linux/blkoops.h | 6 ++- > include/linux/pstore_blk.h | 8 +++- > 5 files changed, 112 insertions(+), 26 deletions(-) > > diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig > index bbf1fdb5eaa7..5f0a42823028 100644 > --- a/fs/pstore/Kconfig > +++ b/fs/pstore/Kconfig > @@ -198,6 +198,18 @@ config PSTORE_BLKOOPS_PMSG_SIZE > NOTE that, both kconfig and module parameters can configure blkoops, > but module parameters have priority over kconfig. > > +config PSTORE_BLKOOPS_CONSOLE_SIZE > + int "console size in kbytes for blkoops" > + depends on PSTORE_BLKOOPS > + depends on PSTORE_CONSOLE > + default 64 Same tricks here as for the PMSG. > + help > + This just sets size of console (console_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 blkoops, > + but module parameters have priority over kconfig. > + > config PSTORE_BLKOOPS_BLKDEV > string "block device for blkoops" > depends on PSTORE_BLKOOPS > diff --git a/fs/pstore/blkoops.c b/fs/pstore/blkoops.c > index 02e6e4c1f965..05990bc3b168 100644 > --- a/fs/pstore/blkoops.c > +++ b/fs/pstore/blkoops.c > @@ -20,6 +20,10 @@ > module_param(pmsg_size, long, 0400); > MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes"); > > +static long console_size = -1; > +module_param(console_size, long, 0400); > +MODULE_PARM_DESC(console_size, "console size in kbytes"); > + > static int dump_oops = -1; > module_param(dump_oops, int, 0400); > MODULE_PARM_DESC(total_size, "whether dump oops"); > @@ -70,6 +74,12 @@ > #define DEFAULT_PMSG_SIZE 0 > #endif > > +#ifdef CONFIG_PSTORE_BLKOOPS_CONSOLE_SIZE > +#define DEFAULT_CONSOLE_SIZE CONFIG_PSTORE_BLKOOPS_CONSOLE_SIZE > +#else > +#define DEFAULT_CONSOLE_SIZE 0 > +#endif > + > #ifdef CONFIG_PSTORE_BLKOOPS_DUMP_OOPS > #define DEFAULT_DUMP_OOPS CONFIG_PSTORE_BLKOOPS_DUMP_OOPS > #else > @@ -124,6 +134,7 @@ int blkoops_register_device(struct blkoops_device *bo_dev) > > verify_size(dmesg_size, DEFAULT_DMESG_SIZE, 4096); > verify_size(pmsg_size, DEFAULT_PMSG_SIZE, 4096); > + verify_size(console_size, DEFAULT_CONSOLE_SIZE, 4096); > #undef verify_size > dump_oops = !!(dump_oops < 0 ? DEFAULT_DUMP_OOPS : dump_oops); > > diff --git a/fs/pstore/blkzone.c b/fs/pstore/blkzone.c > index a3464252d52e..9a7e9b06ccf7 100644 > --- a/fs/pstore/blkzone.c > +++ b/fs/pstore/blkzone.c > @@ -88,9 +88,11 @@ struct blkz_zone { > struct blkz_context { > struct blkz_zone **dbzs; /* dmesg block zones */ > struct blkz_zone *pbz; /* Pmsg block zone */ > + struct blkz_zone *cbz; /* console block zone */ > unsigned int dmesg_max_cnt; > unsigned int dmesg_read_cnt; > unsigned int pmsg_read_cnt; > + unsigned int console_read_cnt; > unsigned int dmesg_write_cnt; > /* > * the counter should be recovered when recover. > @@ -111,6 +113,9 @@ struct blkz_context { > }; > static struct blkz_context blkz_cxt; > > +static void blkz_flush_all_dirty_zones(struct work_struct *); > +static DECLARE_WORK(blkz_cleaner, blkz_flush_all_dirty_zones); > + > enum blkz_flush_mode { > FLUSH_NONE = 0, > FLUSH_PART, > @@ -200,6 +205,9 @@ static int blkz_zone_write(struct blkz_zone *zone, > return 0; > set_dirty: > atomic_set(&zone->dirty, true); > + /* flush dirty zones nicely */ > + if (wcnt == -EBUSY && !is_on_panic()) > + schedule_work(&blkz_cleaner); > return -EBUSY; > } > > @@ -266,6 +274,15 @@ static int blkz_move_zone(struct blkz_zone *old, struct blkz_zone *new) > return 0; > } > > +static void blkz_flush_all_dirty_zones(struct work_struct *work) > +{ > + struct blkz_context *cxt = &blkz_cxt; > + > + blkz_flush_dirty_zone(cxt->pbz); > + blkz_flush_dirty_zone(cxt->cbz); > + blkz_flush_dirty_zones(cxt->dbzs, cxt->dmesg_max_cnt); > +} > + > static int blkz_recover_dmesg_data(struct blkz_context *cxt) > { > struct blkz_info *info = cxt->bzinfo; > @@ -419,15 +436,13 @@ static int blkz_recover_dmesg(struct blkz_context *cxt) > return ret; > } > > -static int blkz_recover_pmsg(struct blkz_context *cxt) > +static int blkz_recover_zone(struct blkz_context *cxt, struct blkz_zone *zone) > { > struct blkz_info *info = cxt->bzinfo; > struct blkz_buffer *oldbuf; > - struct blkz_zone *zone = NULL; > int ret = 0; > ssize_t rcnt, len; > > - zone = cxt->pbz; > if (!zone || zone->oldbuf) > return 0; > > @@ -493,7 +508,11 @@ static inline int blkz_recovery(struct blkz_context *cxt) > if (ret) > goto recover_fail; > > - ret = blkz_recover_pmsg(cxt); > + ret = blkz_recover_zone(cxt, cxt->pbz); > + if (ret) > + goto recover_fail; > + > + ret = blkz_recover_zone(cxt, cxt->cbz); > if (ret) > goto recover_fail; > > @@ -512,6 +531,7 @@ static int blkz_pstore_open(struct pstore_info *psi) > > cxt->dmesg_read_cnt = 0; > cxt->pmsg_read_cnt = 0; > + cxt->console_read_cnt = 0; > return 0; > } > > @@ -539,7 +559,7 @@ static inline int blkz_dmesg_erase(struct blkz_context *cxt, > return blkz_zone_write(zone, FLUSH_META, NULL, 0, 0); > } > > -static inline int blkz_pmsg_erase(struct blkz_context *cxt, > +static inline int blkz_record_erase(struct blkz_context *cxt, > struct blkz_zone *zone) > { > if (unlikely(!blkz_old_ok(zone))) > @@ -566,9 +586,10 @@ static int blkz_pstore_erase(struct pstore_record *record) > case PSTORE_TYPE_DMESG: > return blkz_dmesg_erase(cxt, cxt->dbzs[record->id]); > case PSTORE_TYPE_PMSG: > - return blkz_pmsg_erase(cxt, cxt->pbz); > - default: > - return -EINVAL; > + return blkz_record_erase(cxt, cxt->pbz); > + case PSTORE_TYPE_CONSOLE: > + return blkz_record_erase(cxt, cxt->cbz); > + default: return -EINVAL; > } > } > > @@ -653,17 +674,15 @@ static int notrace blkz_dmesg_write(struct blkz_context *cxt, > return 0; > } > > -static int notrace blkz_pmsg_write(struct blkz_context *cxt, > - struct pstore_record *record) > +static int notrace blkz_record_write(struct blkz_context *cxt, > + struct blkz_zone *zone, struct pstore_record *record) How about generalizing this earlier in the patch series instead of mutating it here? > { > - struct blkz_zone *zone; > size_t start, rem; > int cnt = record->size; > bool is_full_data = false; > char *buf = record->buf; > > - zone = cxt->pbz; > - if (!zone) > + if (!zone || !record) > return -ENOSPC; > > if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size) > @@ -710,11 +729,20 @@ static int notrace blkz_pstore_write(struct pstore_record *record) > record->reason == KMSG_DUMP_PANIC) > atomic_set(&cxt->on_panic, 1); > > + /* > + * if on panic, do not write except dmesg records > + * Fix case that panic_write prints log which wakes up console recorder. > + */ > + if (is_on_panic() && record->type != PSTORE_TYPE_DMESG) > + return -EBUSY; > + > switch (record->type) { > case PSTORE_TYPE_DMESG: > return blkz_dmesg_write(cxt, record); > + case PSTORE_TYPE_CONSOLE: > + return blkz_record_write(cxt, cxt->cbz, record); > case PSTORE_TYPE_PMSG: > - return blkz_pmsg_write(cxt, record); > + return blkz_record_write(cxt, cxt->pbz, record); > default: > return -EINVAL; > } > @@ -738,6 +766,13 @@ static struct blkz_zone *blkz_read_next_zone(struct blkz_context *cxt) > return zone; > } > > + if (cxt->console_read_cnt == 0) { > + cxt->console_read_cnt++; > + zone = cxt->cbz; > + if (blkz_old_ok(zone)) > + return zone; > + } > + > return NULL; > } > > @@ -799,7 +834,7 @@ static ssize_t blkz_dmesg_read(struct blkz_zone *zone, > return size + hlen; > } > > -static ssize_t blkz_pmsg_read(struct blkz_zone *zone, > +static ssize_t blkz_record_read(struct blkz_zone *zone, > struct pstore_record *record) > { > size_t size, start; > @@ -825,7 +860,7 @@ static ssize_t blkz_pmsg_read(struct blkz_zone *zone, > static ssize_t blkz_pstore_read(struct pstore_record *record) > { > struct blkz_context *cxt = record->psi->data; > - ssize_t (*blkz_read)(struct blkz_zone *zone, > + ssize_t (*readop)(struct blkz_zone *zone, > struct pstore_record *record); > struct blkz_zone *zone; > ssize_t ret; > @@ -843,17 +878,19 @@ static ssize_t blkz_pstore_read(struct pstore_record *record) > record->type = zone->type; > switch (record->type) { > case PSTORE_TYPE_DMESG: > - blkz_read = blkz_dmesg_read; > + readop = blkz_dmesg_read; > record->id = cxt->dmesg_read_cnt - 1; > break; > + case PSTORE_TYPE_CONSOLE: > + /* fallthrough */ Since this case has no body, you can leave off the "fallthrough". (But if you want to mark it anyway, please use "fallthrough;" instead of a comment.) > case PSTORE_TYPE_PMSG: > - blkz_read = blkz_pmsg_read; > + readop = blkz_record_read; > break; > default: > goto next_zone; > } > > - ret = blkz_read(zone, record); > + ret = readop(zone, record); > if (ret == READ_NEXT_ZONE) > goto next_zone; > return ret; > @@ -1001,15 +1038,25 @@ static int blkz_cut_zones(struct blkz_context *cxt) > goto fail_out; > } > > + off_size += info->console_size; > + cxt->cbz = blkz_init_zone(PSTORE_TYPE_CONSOLE, &off, > + info->console_size); > + if (IS_ERR(cxt->cbz)) { > + err = PTR_ERR(cxt->cbz); > + goto free_pmsg; > + } > + > cxt->dbzs = blkz_init_zones(PSTORE_TYPE_DMESG, &off, > info->total_size - off_size, > info->dmesg_size, &cxt->dmesg_max_cnt); > if (IS_ERR(cxt->dbzs)) { > err = PTR_ERR(cxt->dbzs); > - goto free_pmsg; > + goto free_console; > } > > return 0; > +free_console: > + blkz_free_zone(&cxt->cbz); > free_pmsg: > blkz_free_zone(&cxt->pbz); > fail_out: > @@ -1027,7 +1074,7 @@ int blkz_register(struct blkz_info *info) > return -EINVAL; > } > > - if (!info->dmesg_size && !info->pmsg_size) { > + if (!info->dmesg_size && !info->pmsg_size && !info->console_size) { > pr_warn("at least one of the records be non-zero\n"); > return -EINVAL; > } > @@ -1055,6 +1102,7 @@ int blkz_register(struct blkz_info *info) > check_size(total_size, 4096); > check_size(dmesg_size, SECTOR_SIZE); > check_size(pmsg_size, SECTOR_SIZE); > + check_size(console_size, SECTOR_SIZE); > > #undef check_size > > @@ -1087,6 +1135,7 @@ int blkz_register(struct blkz_info *info) > pr_debug("\ttotal size : %ld Bytes\n", info->total_size); > pr_debug("\tdmesg size : %ld Bytes\n", info->dmesg_size); > pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size); > + pr_debug("\tconsole size : %ld Bytes\n", info->console_size); > > err = blkz_cut_zones(cxt); > if (err) { > @@ -1108,11 +1157,15 @@ int blkz_register(struct blkz_info *info) > cxt->pstore.flags |= PSTORE_FLAGS_DMESG; > if (info->pmsg_size) > cxt->pstore.flags |= PSTORE_FLAGS_PMSG; > + if (info->console_size) > + cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; > > - pr_info("Registered %s as blkzone backend for %s%s%s\n", info->name, > + pr_info("Registered %s as blkzone backend for %s%s%s%s\n", > + info->name, > cxt->dbzs && cxt->bzinfo->dump_oops ? "Oops " : "", > cxt->dbzs && cxt->bzinfo->panic_write ? "Panic " : "", > - cxt->pbz ? "Pmsg" : ""); > + cxt->pbz ? "Pmsg " : "", > + cxt->cbz ? "Console" : ""); > > err = pstore_register(&cxt->pstore); > if (err) { > @@ -1139,6 +1192,8 @@ void blkz_unregister(struct blkz_info *info) > { > struct blkz_context *cxt = &blkz_cxt; > > + flush_work(&blkz_cleaner); > + > pstore_unregister(&cxt->pstore); > kfree(cxt->pstore.buf); > cxt->pstore.bufsize = 0; > diff --git a/include/linux/blkoops.h b/include/linux/blkoops.h > index fe63739309aa..8f40f225545d 100644 > --- a/include/linux/blkoops.h > +++ b/include/linux/blkoops.h > @@ -23,8 +23,10 @@ > * Both of the @size and @offset parameters on this interface are > * the relative size of the space provided, not the whole disk/flash. > * > - * On success, the number of bytes read should be returned. > - * On error, negative number should be returned. > + * On success, the number of bytes read/write should be returned. > + * On error, negative number should be returned. The following returning > + * number means more: > + * -EBUSY: pstore/blk should try again later. > * @panic_write: > * The write operation only used for panic. > * > diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h > index af06be25bd01..546375e04419 100644 > --- a/include/linux/pstore_blk.h > +++ b/include/linux/pstore_blk.h > @@ -22,6 +22,9 @@ > * @pmsg_size: > * The size of zone for pmsg. Zero means disabled, othewise, it must be > * multiple of SECTOR_SIZE(512). > + * @console_size: > + * The size of zone for console. Zero means disabled, othewise, it must > + * be multiple of SECTOR_SIZE(512). > * @dump_oops: > * Dump oops and panic log or only panic. > * @read, @write: > @@ -33,7 +36,9 @@ > * the relative size of the space provided, not the whole disk/flash. > * > * On success, the number of bytes read/write should be returned. > - * On error, negative number should be returned. > + * On error, negative number should be returned. The following returning > + * number means more: > + * -EBUSY: pstore/blk should try again later. > * @panic_write: > * The write operation only used for panic. It's optional if you do not > * care panic record. If panic occur but blkzone do not recover yet, the > @@ -54,6 +59,7 @@ struct blkz_info { > unsigned long total_size; > unsigned long dmesg_size; > unsigned long pmsg_size; > + unsigned long console_size; > int dump_oops; > blkz_read_op read; > blkz_write_op write; > -- > 1.9.1 > -- Kees Cook