On Mon, Jan 7, 2019 at 4:01 AM liaoweixiong
<liaoweixiong@xxxxxxxxxxxxxxxxx> wrote:
>
> It is a sample for pstore_blk, using general ram rather than block device.
> According to pstore_blk, the data will be saved to ram buffer if not
> register device path and apis for panic. So, it can only used to dump
> Oops and some things will not reboot.
I'm not sure I see the purpose of this implementation? Doesn't this
just cause all the pstore machinery to skip any actions? i.e. without
bzinfo->part_path, won't blkz_sample_write() just return -EINVAL, etc?
>
> Signed-off-by: liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxx>
> ---
> fs/pstore/Kconfig | 9 +++++++++
> fs/pstore/Makefile | 2 ++
> fs/pstore/blkbuf.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 57 insertions(+)
> create mode 100644 fs/pstore/blkbuf.c
>
> diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
> index a881c53..18b1fe6 100644
> --- a/fs/pstore/Kconfig
> +++ b/fs/pstore/Kconfig
> @@ -159,3 +159,12 @@ config PSTORE_BLK
> help
> This enables panic and oops message to be logged to a block dev
> where it can be read back at some later point.
> +
> +config PSTORE_BLKBUF
> + tristate "pstore block buffer sample"
> + depends on PSTORE_BLK
> + help
> + This is a sample for pstore block, but do NOT have a block dev.
> + According to pstore_blk, the data will be saved to ram buffer and
> + dropped when reboot. So, it can only used to dump Oops and some
> + things will not reboot.
> diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
> index c431700..4a6cde1 100644
> --- a/fs/pstore/Makefile
> +++ b/fs/pstore/Makefile
> @@ -15,3 +15,5 @@ obj-$(CONFIG_PSTORE_RAM) += ramoops.o
>
> obj-$(CONFIG_PSTORE_BLK) += pstore_blk.o
> pstore_blk-y += blkzone.o
> +
> +obj-$(CONFIG_PSTORE_BLKBUF) += blkbuf.o
> diff --git a/fs/pstore/blkbuf.c b/fs/pstore/blkbuf.c
> new file mode 100644
> index 0000000..f1c6f57
> --- /dev/null
> +++ b/fs/pstore/blkbuf.c
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + *
> + * blkbuf.c: Block device Oops/Panic logger
> + *
> + * Copyright (C) 2019 liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +#define pr_fmt(fmt) "blkbuf: " fmt
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pstore_blk.h>
> +
> +struct blkz_info blkbuf_info = {
> + .owner = THIS_MODULE,
> + .name = "blkbuf",
> + .part_size = 512 * 1024,
> + .dmesg_size = 64 * 1024,
> + .dump_oops = true,
> +};
> +
> +static int __init blkbuf_init(void)
> +{
> + return blkz_register(&blkbuf_info);
> +}
> +module_init(blkbuf_init);
> +
> +static void __exit blkbuf_exit(void)
> +{
> + blkz_unregister(&blkbuf_info);
> +}
> +module_exit(blkbuf_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Sample for Pstore BLK with Oops logger");
> --
> 1.9.1
>
--
Kees Cook
