From: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx> In order to configure itself, the MTD backend needs to be able to query the current pstore configuration. Introduce pstore_blk_get_config() for this purpose. Signed-off-by: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/1585126506-18635-10-git-send-email-liaoweixiong@xxxxxxxxxxxxxxxxx Co-developed-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- fs/pstore/blk.c | 37 ++++++++++++++++++++++++++++++------- include/linux/pstore_blk.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+), 7 deletions(-) diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 8c78eb9906fb..95436cff8976 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -94,6 +94,17 @@ struct bdev_info { sector_t start_sect; }; +#define check_size(name, alignsize) ({ \ + long _##name_ = (name); \ + _##name_ = _##name_ <= 0 ? 0 : (_##name_ * 1024); \ + if (_##name_ & ((alignsize) - 1)) { \ + pr_info(#name " must align to %d\n", \ + (alignsize)); \ + _##name_ = ALIGN(name, (alignsize)); \ + } \ + _##name_; \ +}) + /** * struct pstore_device_info - back-end pstore/blk driver structure. * @@ -149,13 +160,11 @@ static int psblk_register_do(struct pstore_device_info *dev) dev->flags = UINT_MAX; #define verify_size(name, alignsize, enabled) { \ - long _##name_ = (enabled) ? (name) : 0; \ - _##name_ = _##name_ <= 0 ? 0 : (_##name_ * 1024); \ - if (_##name_ & ((alignsize) - 1)) { \ - pr_info(#name " must align to %d\n", \ - (alignsize)); \ - _##name_ = ALIGN(name, (alignsize)); \ - } \ + long _##name_; \ + if (enabled) \ + _##name_ = check_size(name, alignsize); \ + else \ + _##name_ = 0; \ name = _##name_ / 1024; \ pstore_zone_info->name = _##name_; \ } @@ -456,6 +465,20 @@ void unregister_pstore_blk(unsigned int major) } EXPORT_SYMBOL_GPL(unregister_pstore_blk); +/* get information of pstore/blk */ +int pstore_blk_get_config(struct pstore_blk_config *info) +{ + strncpy(info->device, blkdev, 80); + info->max_reason = max_reason; + info->kmsg_size = check_size(kmsg_size, 4096); + info->pmsg_size = check_size(pmsg_size, 4096); + info->ftrace_size = check_size(ftrace_size, 4096); + info->console_size = check_size(console_size, 4096); + + return 0; +} +EXPORT_SYMBOL_GPL(pstore_blk_get_config); + static void __exit pstore_blk_exit(void) { mutex_lock(&pstore_blk_lock); diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index ccba8c068752..0c40774e71e0 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -49,4 +49,32 @@ struct pstore_blk_info { int register_pstore_blk(struct pstore_blk_info *info); void unregister_pstore_blk(unsigned int major); +/** + * struct pstore_blk_config - the pstore_blk backend configuration + * + * @device: Name of the desired block device + * @max_reason: Maximum kmsg dump reason to store to block device + * @kmsg_size: Total size of for kmsg dumps + * @pmsg_size: Total size of the pmsg storage area + * @console_size: Total size of the console storage area + * @ftrace_size: Total size for ftrace logging data (for all CPUs) + */ +struct pstore_blk_config { + char device[80]; + enum kmsg_dump_reason max_reason; + unsigned long kmsg_size; + unsigned long pmsg_size; + unsigned long console_size; + unsigned long ftrace_size; +}; + +/** + * pstore_blk_get_config - get a copy of the pstore_blk backend configuration + * + * @info: The sturct pstore_blk_config to be filled in + * + * Failure returns negative error code, and success returns 0. + */ +int pstore_blk_get_config(struct pstore_blk_config *info); + #endif -- 2.20.1
