Commit 0edae0b3 authored by Kees Cook's avatar Kees Cook

pstore: Add kernel-doc for struct pstore_info

This adds documentation for struct pstore_info, which also includes
the basic API the backends need to implement.
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 0d7cd09a
...@@ -30,7 +30,7 @@ ...@@ -30,7 +30,7 @@
#include <linux/time.h> #include <linux/time.h>
#include <linux/types.h> #include <linux/types.h>
/* types */ /* pstore record types (see fs/pstore/inode.c for filename templates) */
enum pstore_type_id { enum pstore_type_id {
PSTORE_TYPE_DMESG = 0, PSTORE_TYPE_DMESG = 0,
PSTORE_TYPE_MCE = 1, PSTORE_TYPE_MCE = 1,
...@@ -47,14 +47,138 @@ enum pstore_type_id { ...@@ -47,14 +47,138 @@ enum pstore_type_id {
struct module; struct module;
/**
* struct pstore_info - backend pstore driver structure
*
* @owner: module which is repsonsible for this backend driver
* @name: name of the backend driver
*
* @buf_lock: spinlock to serialize access to @buf
* @buf: preallocated crash dump buffer
* @bufsize: size of @buf available for crash dump writes
*
* @read_mutex: serializes @open, @read, @close, and @erase callbacks
* @flags: bitfield of frontends the backend can accept writes for
* @data: backend-private pointer passed back during callbacks
*
* Callbacks:
*
* @open:
* Notify backend that pstore is starting a full read of backend
* records. Followed by one or more @read calls, and a final @close.
*
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns 0 on success, and non-zero on error.
*
* @close:
* Notify backend that pstore has finished a full read of backend
* records. Always preceded by an @open call and one or more @read
* calls.
*
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns 0 on success, and non-zero on error. (Though pstore will
* ignore the error.)
*
* @read:
* Read next available backend record. Called after a successful
* @open.
*
* @id: out: unique identifier for the record
* @type: out: pstore record type
* @count: out: for PSTORE_TYPE_DMESG, the Oops count.
* @time: out: timestamp for the record
* @buf: out: kmalloc copy of record contents, to be freed by pstore
* @compressed:
* out: if the record contents are compressed
* @ecc_notice_size:
* out: ECC information
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns record size on success, zero when no more records are
* available, or negative on error.
*
* @write:
* Perform a frontend notification of a write to a backend record. The
* data to be stored has already been written to the registered @buf
* of the @psi structure.
*
* @type: in: pstore record type to write
* @reason:
* in: pstore write reason
* @id: out: unique identifier for the record
* @part: in: position in a multipart write
* @count: in: increasing from 0 since boot, the number of this Oops
* @compressed:
* in: if the record is compressed
* @size: in: size of the write
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns 0 on success, and non-zero on error.
*
* @write_buf:
* Perform a frontend write to a backend record, using a specified
* buffer. Unlike @write, this does not use the @psi @buf.
*
* @type: in: pstore record type to write
* @reason:
* in: pstore write reason
* @id: out: unique identifier for the record
* @part: in: position in a multipart write
* @buf: in: pointer to contents to write to backend record
* @compressed:
* in: if the record is compressed
* @size: in: size of the write
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns 0 on success, and non-zero on error.
*
* @write_buf_user:
* Perform a frontend write to a backend record, using a specified
* buffer that is coming directly from userspace.
*
* @type: in: pstore record type to write
* @reason:
* in: pstore write reason
* @id: out: unique identifier for the record
* @part: in: position in a multipart write
* @buf: in: pointer to userspace contents to write to backend record
* @compressed:
* in: if the record is compressed
* @size: in: size of the write
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns 0 on success, and non-zero on error.
*
* @erase:
* Delete a record from backend storage. Different backends
* identify records differently, so all possible methods of
* identification are included to help the backend locate the
* record to remove.
*
* @type: in: pstore record type to write
* @id: in: per-type unique identifier for the record
* @count: in: Oops count
* @time: in: timestamp for the record
* @psi: in: pointer to the struct pstore_info for the backend
*
* Returns 0 on success, and non-zero on error.
*
*/
struct pstore_info { struct pstore_info {
struct module *owner; struct module *owner;
char *name; char *name;
spinlock_t buf_lock; /* serialize access to 'buf' */
spinlock_t buf_lock;
char *buf; char *buf;
size_t bufsize; size_t bufsize;
struct mutex read_mutex; /* serialize open/read/close */
struct mutex read_mutex;
int flags; int flags;
void *data;
int (*open)(struct pstore_info *psi); int (*open)(struct pstore_info *psi);
int (*close)(struct pstore_info *psi); int (*close)(struct pstore_info *psi);
ssize_t (*read)(u64 *id, enum pstore_type_id *type, ssize_t (*read)(u64 *id, enum pstore_type_id *type,
...@@ -76,11 +200,10 @@ struct pstore_info { ...@@ -76,11 +200,10 @@ struct pstore_info {
int (*erase)(enum pstore_type_id type, u64 id, int (*erase)(enum pstore_type_id type, u64 id,
int count, struct timespec time, int count, struct timespec time,
struct pstore_info *psi); struct pstore_info *psi);
void *data;
}; };
/* Supported frontends */
#define PSTORE_FLAGS_DMESG (1 << 0) #define PSTORE_FLAGS_DMESG (1 << 0)
#define PSTORE_FLAGS_FRAGILE PSTORE_FLAGS_DMESG
#define PSTORE_FLAGS_CONSOLE (1 << 1) #define PSTORE_FLAGS_CONSOLE (1 << 1)
#define PSTORE_FLAGS_FTRACE (1 << 2) #define PSTORE_FLAGS_FTRACE (1 << 2)
#define PSTORE_FLAGS_PMSG (1 << 3) #define PSTORE_FLAGS_PMSG (1 << 3)
......
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