From cbf82e35031b135928f36e72c6d166e935530b6a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 16 Oct 2020 15:20:39 +0200 Subject: pstore/zone: cap the maximum device size Introduce an abritrary 128MiB cap to avoid malloc failures when using a larger block device. Signed-off-by: Christoph Hellwig Reviewed-by: WeiXiong Liao Reviewed-by: Kees Cook Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201016132047.3068029-2-hch@lst.de --- fs/pstore/zone.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index 3ce89216670c..5266ccbec007 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -1299,6 +1299,10 @@ int register_pstore_zone(struct pstore_zone_info *info) pr_warn("total_size must be >= 4096\n"); return -EINVAL; } + if (info->total_size > SZ_128M) { + pr_warn("capping size to 128MiB\n"); + info->total_size = SZ_128M; + } if (!info->kmsg_size && !info->pmsg_size && !info->console_size && !info->ftrace_size) { -- cgit v1.2.1 From 45a8af4412b1143760cbc7255b8c53271df89ed7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 16 Oct 2020 15:20:40 +0200 Subject: pstore/blk: update the command line example Use the human readable device name instead of the device number, and add the required best_effort parameter. Signed-off-by: Christoph Hellwig Reviewed-by: WeiXiong Liao Reviewed-by: Kees Cook Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201016132047.3068029-3-hch@lst.de --- Documentation/admin-guide/pstore-blk.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/admin-guide/pstore-blk.rst b/Documentation/admin-guide/pstore-blk.rst index 6898aba9fb5c..83543cb3daa1 100644 --- a/Documentation/admin-guide/pstore-blk.rst +++ b/Documentation/admin-guide/pstore-blk.rst @@ -35,7 +35,7 @@ module parameters have priority over Kconfig. Here is an example for module parameters:: - pstore_blk.blkdev=179:7 pstore_blk.kmsg_size=64 + pstore_blk.blkdev=/dev/mmcblk0p7 pstore_blk.kmsg_size=64 best_effort=y The detail of each configurations may be of interest to you. -- cgit v1.2.1 From b6f8ed33ab2bbc58e40fb1e2fb0f9c90cab04baf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 16 Oct 2020 15:20:41 +0200 Subject: pstore/blk: remove {un,}register_pstore_blk This interface is entirely unused, so remove them and various bits of unreachable code. Signed-off-by: Christoph Hellwig Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201016132047.3068029-4-hch@lst.de --- Documentation/admin-guide/pstore-blk.rst | 5 +- fs/pstore/blk.c | 83 ++++---------------------------- include/linux/pstore_blk.h | 42 ---------------- 3 files changed, 11 insertions(+), 119 deletions(-) diff --git a/Documentation/admin-guide/pstore-blk.rst b/Documentation/admin-guide/pstore-blk.rst index 83543cb3daa1..49d8149f8d32 100644 --- a/Documentation/admin-guide/pstore-blk.rst +++ b/Documentation/admin-guide/pstore-blk.rst @@ -151,10 +151,7 @@ otherwise KMSG_DUMP_MAX. Configurations for driver ------------------------- -Only a block device driver cares about these configurations. A block device -driver uses ``register_pstore_blk`` to register to pstore/blk. - -A non-block device driver uses ``register_pstore_device`` with +A device driver uses ``register_pstore_device`` with ``struct pstore_device_info`` to register to pstore/blk. .. kernel-doc:: fs/pstore/blk.c diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index fcd5563dde06..882d0bc0cfd7 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -90,7 +90,6 @@ MODULE_PARM_DESC(blkdev, "block device for pstore storage"); static DEFINE_MUTEX(pstore_blk_lock); static struct block_device *psblk_bdev; static struct pstore_zone_info *pstore_zone_info; -static pstore_blk_panic_write_op blkdev_panic_write; struct bdev_info { dev_t devt; @@ -341,24 +340,11 @@ static ssize_t psblk_generic_blk_write(const char *buf, size_t bytes, return ret; } -static ssize_t psblk_blk_panic_write(const char *buf, size_t size, - loff_t off) -{ - int ret; - - if (!blkdev_panic_write) - return -EOPNOTSUPP; - - /* size and off must align to SECTOR_SIZE for block device */ - ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT, - size >> SECTOR_SHIFT); - /* try next zone */ - if (ret == -ENOMSG) - return ret; - return ret ? -EIO : size; -} - -static int __register_pstore_blk(struct pstore_blk_info *info) +/* + * This takes its configuration only from the module parameters now. + * See psblk_get_bdev() and blkdev. + */ +static int __register_pstore_blk(void) { char bdev_name[BDEVNAME_SIZE]; struct block_device *bdev; @@ -378,68 +364,34 @@ static int __register_pstore_blk(struct pstore_blk_info *info) } /* only allow driver matching the @blkdev */ - if (!binfo.devt || (!best_effort && - MAJOR(binfo.devt) != info->major)) { - pr_debug("invalid major %u (expect %u)\n", - info->major, MAJOR(binfo.devt)); + if (!binfo.devt) { + pr_debug("no major\n"); ret = -ENODEV; goto err_put_bdev; } /* psblk_bdev must be assigned before register to pstore/blk */ psblk_bdev = bdev; - blkdev_panic_write = info->panic_write; - - /* Copy back block device details. */ - info->devt = binfo.devt; - info->nr_sects = binfo.nr_sects; - info->start_sect = binfo.start_sect; memset(&dev, 0, sizeof(dev)); - dev.total_size = info->nr_sects << SECTOR_SHIFT; - dev.flags = info->flags; + dev.total_size = binfo.nr_sects << SECTOR_SHIFT; dev.read = psblk_generic_blk_read; dev.write = psblk_generic_blk_write; - dev.erase = NULL; - dev.panic_write = info->panic_write ? psblk_blk_panic_write : NULL; ret = __register_pstore_device(&dev); if (ret) goto err_put_bdev; bdevname(bdev, bdev_name); - pr_info("attached %s%s\n", bdev_name, - info->panic_write ? "" : " (no dedicated panic_write!)"); + pr_info("attached %s (no dedicated panic_write!)\n", bdev_name); return 0; err_put_bdev: psblk_bdev = NULL; - blkdev_panic_write = NULL; psblk_put_bdev(bdev, holder); return ret; } -/** - * register_pstore_blk() - register block device to pstore/blk - * - * @info: details on the desired block device interface - * - * Return: - * * 0 - OK - * * Others - something error. - */ -int register_pstore_blk(struct pstore_blk_info *info) -{ - int ret; - - mutex_lock(&pstore_blk_lock); - ret = __register_pstore_blk(info); - mutex_unlock(&pstore_blk_lock); - - return ret; -} -EXPORT_SYMBOL_GPL(register_pstore_blk); - static void __unregister_pstore_blk(unsigned int major) { struct pstore_device_info dev = { .read = psblk_generic_blk_read }; @@ -449,24 +401,10 @@ static void __unregister_pstore_blk(unsigned int major) if (psblk_bdev && MAJOR(psblk_bdev->bd_dev) == major) { __unregister_pstore_device(&dev); psblk_put_bdev(psblk_bdev, holder); - blkdev_panic_write = NULL; psblk_bdev = NULL; } } -/** - * unregister_pstore_blk() - unregister block device from pstore/blk - * - * @major: the major device number of device - */ -void unregister_pstore_blk(unsigned int major) -{ - mutex_lock(&pstore_blk_lock); - __unregister_pstore_blk(major); - mutex_unlock(&pstore_blk_lock); -} -EXPORT_SYMBOL_GPL(unregister_pstore_blk); - /* get information of pstore/blk */ int pstore_blk_get_config(struct pstore_blk_config *info) { @@ -483,12 +421,11 @@ EXPORT_SYMBOL_GPL(pstore_blk_get_config); static int __init pstore_blk_init(void) { - struct pstore_blk_info info = { }; int ret = 0; mutex_lock(&pstore_blk_lock); if (!pstore_zone_info && best_effort && blkdev[0]) - ret = __register_pstore_blk(&info); + ret = __register_pstore_blk(); mutex_unlock(&pstore_blk_lock); return ret; diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index 61e914522b01..99564f93d774 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -7,48 +7,6 @@ #include #include -/** - * typedef pstore_blk_panic_write_op - panic write operation to block device - * - * @buf: the data to write - * @start_sect: start sector to block device - * @sects: sectors count on buf - * - * Return: On success, zero should be returned. Others excluding -ENOMSG - * mean error. -ENOMSG means to try next zone. - * - * Panic write to block device must be aligned to SECTOR_SIZE. - */ -typedef int (*pstore_blk_panic_write_op)(const char *buf, sector_t start_sect, - sector_t sects); - -/** - * struct pstore_blk_info - pstore/blk registration details - * - * @major: Which major device number to support with pstore/blk - * @flags: The supported PSTORE_FLAGS_* from linux/pstore.h. - * @panic_write:The write operation only used for the panic case. - * This can be NULL, but is recommended to avoid losing - * crash data if the kernel's IO path or work queues are - * broken during a panic. - * @devt: The dev_t that pstore/blk has attached to. - * @nr_sects: Number of sectors on @devt. - * @start_sect: Starting sector on @devt. - */ -struct pstore_blk_info { - unsigned int major; - unsigned int flags; - pstore_blk_panic_write_op panic_write; - - /* Filled in by pstore/blk after registration. */ - dev_t devt; - sector_t nr_sects; - sector_t start_sect; -}; - -int register_pstore_blk(struct pstore_blk_info *info); -void unregister_pstore_blk(unsigned int major); - /** * struct pstore_device_info - back-end pstore/blk driver structure. * -- cgit v1.2.1 From 26fecbf7602dd69b649914e61526bd67c557fece Mon Sep 17 00:00:00 2001 From: Vasile-Laurentiu Stanimir Date: Wed, 4 Nov 2020 15:05:32 +0200 Subject: pstore: Move kmsg_bytes default into Kconfig While kmsg_bytes can be set for pstore via mount, if a crash occurs before the mount only partial console log will be stored as kmsg_bytes defaults to a potentially different hardcoded value in the kernel (PSTORE_DEFAULT_KMSG_BYTES). This makes it impossible to analyze valuable post-mortem data especially on the embedded development or in the process of bringing up new boards. Change this value to be a Kconfig option with the default of old PSTORE_DEFAULT_KMSG_BYTES Signed-off-by: Vasile-Laurentiu Stanimir Signed-off-by: Kees Cook --- fs/pstore/Kconfig | 8 ++++++++ fs/pstore/inode.c | 2 +- fs/pstore/internal.h | 1 - fs/pstore/platform.c | 2 +- 4 files changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index e16a49ebfe54..8adabde685f1 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -14,6 +14,14 @@ config PSTORE If you don't have a platform persistent store driver, say N. +config PSTORE_DEFAULT_KMSG_BYTES + int "Default kernel log storage space" if EXPERT + depends on PSTORE + default "10240" + help + Defines default size of pstore kernel log storage. + Can be enlarged if needed, not recommended to shrink it. + config PSTORE_DEFLATE_COMPRESS tristate "DEFLATE (ZLIB) compression" default y diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index c331efe8de95..93a217e4f563 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -266,7 +266,7 @@ static void parse_options(char *options) */ static int pstore_show_options(struct seq_file *m, struct dentry *root) { - if (kmsg_bytes != PSTORE_DEFAULT_KMSG_BYTES) + if (kmsg_bytes != CONFIG_PSTORE_DEFAULT_KMSG_BYTES) seq_printf(m, ",kmsg_bytes=%lu", kmsg_bytes); return 0; } diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h index 7fb219042f13..801d6c0b170c 100644 --- a/fs/pstore/internal.h +++ b/fs/pstore/internal.h @@ -6,7 +6,6 @@ #include #include -#define PSTORE_DEFAULT_KMSG_BYTES 10240 extern unsigned long kmsg_bytes; #ifdef CONFIG_PSTORE_FTRACE diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 36714df37d5d..32f64abc277c 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -101,7 +101,7 @@ static char *big_oops_buf; static size_t big_oops_buf_sz; /* How much of the console log to snapshot */ -unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES; +unsigned long kmsg_bytes = CONFIG_PSTORE_DEFAULT_KMSG_BYTES; void pstore_set_kmsg_bytes(int bytes) { -- cgit v1.2.1