linux/drivers/nvdimm/pfn.h
Dan Williams 6acd7d5ef2 libnvdimm/namespace: Enforce memremap_compat_align()
The pmem driver on PowerPC crashes with the following signature when
instantiating misaligned namespaces that map their capacity via
memremap_pages().

    BUG: Unable to handle kernel data access at 0xc001000406000000
    Faulting instruction address: 0xc000000000090790
    NIP [c000000000090790] arch_add_memory+0xc0/0x130
    LR [c000000000090744] arch_add_memory+0x74/0x130
    Call Trace:
     arch_add_memory+0x74/0x130 (unreliable)
     memremap_pages+0x74c/0xa30
     devm_memremap_pages+0x3c/0xa0
     pmem_attach_disk+0x188/0x770
     nvdimm_bus_probe+0xd8/0x470

With the assumption that only memremap_pages() has alignment
constraints, enforce memremap_compat_align() for
pmem_should_map_pages(), nd_pfn, and nd_dax cases. This includes
preventing the creation of namespaces where the base address is
misaligned and cases there infoblock padding parameters are invalid.

Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Fixes: a3619190d6 ("libnvdimm/pfn: stop padding pmem namespaces to section alignment")
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-03-17 12:23:21 -07:00

52 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2014-2015, Intel Corporation.
*/
#ifndef __NVDIMM_PFN_H
#define __NVDIMM_PFN_H
#include <linux/types.h>
#include <linux/mmzone.h>
#define PFN_SIG_LEN 16
#define PFN_SIG "NVDIMM_PFN_INFO\0"
#define DAX_SIG "NVDIMM_DAX_INFO\0"
struct nd_pfn_sb {
u8 signature[PFN_SIG_LEN];
u8 uuid[16];
u8 parent_uuid[16];
__le32 flags;
__le16 version_major;
__le16 version_minor;
__le64 dataoff; /* relative to namespace_base + start_pad */
__le64 npfns;
__le32 mode;
/* minor-version-1 additions for section alignment */
/**
* @start_pad: Deprecated attribute to pad start-misaligned namespaces
*
* start_pad is deprecated because the original definition did
* not comprehend that dataoff is relative to the base address
* of the namespace not the start_pad adjusted base. The result
* is that the dax path is broken, but the block-I/O path is
* not. The kernel will no longer create namespaces using start
* padding, but it still supports block-I/O for legacy
* configurations mainly to allow a backup, reconfigure the
* namespace, and restore flow to repair dax operation.
*/
__le32 start_pad;
__le32 end_trunc;
/* minor-version-2 record the base alignment of the mapping */
__le32 align;
/* minor-version-3 guarantee the padding and flags are zero */
/* minor-version-4 record the page size and struct page size */
__le32 page_size;
__le16 page_struct_size;
u8 padding[3994];
__le64 checksum;
};
#endif /* __NVDIMM_PFN_H */