linux/fs/pstore/ram_internal.h
Kees Cook 06b4e09aab pstore/ram: Set freed addresses to NULL
For good measure, set all the freed addresses to NULL when managing
przs.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-5-keescook@chromium.org
2022-10-19 09:25:39 -07:00

99 lines
3.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
* Copyright (C) 2011 Kees Cook <keescook@chromium.org>
* Copyright (C) 2011 Google, Inc.
*/
#include <linux/pstore_ram.h>
/*
* Choose whether access to the RAM zone requires locking or not. If a zone
* can be written to from different CPUs like with ftrace for example, then
* PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required.
*/
#define PRZ_FLAG_NO_LOCK BIT(0)
/*
* If a PRZ should only have a single-boot lifetime, this marks it as
* getting wiped after its contents get copied out after boot.
*/
#define PRZ_FLAG_ZAP_OLD BIT(1)
/**
* struct persistent_ram_zone - Details of a persistent RAM zone (PRZ)
* used as a pstore backend
*
* @paddr: physical address of the mapped RAM area
* @size: size of mapping
* @label: unique name of this PRZ
* @type: frontend type for this PRZ
* @flags: holds PRZ_FLAGS_* bits
*
* @buffer_lock:
* locks access to @buffer "size" bytes and "start" offset
* @buffer:
* pointer to actual RAM area managed by this PRZ
* @buffer_size:
* bytes in @buffer->data (not including any trailing ECC bytes)
*
* @par_buffer:
* pointer into @buffer->data containing ECC bytes for @buffer->data
* @par_header:
* pointer into @buffer->data containing ECC bytes for @buffer header
* (i.e. all fields up to @data)
* @rs_decoder:
* RSLIB instance for doing ECC calculations
* @corrected_bytes:
* ECC corrected bytes accounting since boot
* @bad_blocks:
* ECC uncorrectable bytes accounting since boot
* @ecc_info:
* ECC configuration details
*
* @old_log:
* saved copy of @buffer->data prior to most recent wipe
* @old_log_size:
* bytes contained in @old_log
*
*/
struct persistent_ram_zone {
phys_addr_t paddr;
size_t size;
void *vaddr;
char *label;
enum pstore_type_id type;
u32 flags;
raw_spinlock_t buffer_lock;
struct persistent_ram_buffer *buffer;
size_t buffer_size;
char *par_buffer;
char *par_header;
struct rs_control *rs_decoder;
int corrected_bytes;
int bad_blocks;
struct persistent_ram_ecc_info ecc_info;
char *old_log;
size_t old_log_size;
};
struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
u32 sig, struct persistent_ram_ecc_info *ecc_info,
unsigned int memtype, u32 flags, char *label);
void persistent_ram_free(struct persistent_ram_zone **_prz);
void persistent_ram_zap(struct persistent_ram_zone *prz);
int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
unsigned int count);
int persistent_ram_write_user(struct persistent_ram_zone *prz,
const void __user *s, unsigned int count);
void persistent_ram_save_old(struct persistent_ram_zone *prz);
size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
void *persistent_ram_old(struct persistent_ram_zone *prz);
void persistent_ram_free_old(struct persistent_ram_zone *prz);
ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
char *str, size_t len);