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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-02 20:35:45 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-02 20:35:45 +0300
commit2575be8ad32f9910d7e7c118e73f529b8d5b8b7b (patch)
treeae27a631c15914e0870813af57d443fbd4ad0acf /include
parentc58d4055c054fc6dc72f1be8bc71bd6fff209e48 (diff)
parent3a7d2fd16c57a1ef47dc2891171514231c9c7c6e (diff)
downloadlinux-2575be8ad32f9910d7e7c118e73f529b8d5b8b7b.tar.xz
Merge tag 'pstore-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull pstore updates from Kees Cook: "This has a large internal refactoring along with several smaller fixes. - constify compression structures; Bhumika Goyal - restore powerpc dumping; Ankit Kumar - fix more bugs in the rarely exercises module unloading logic - reorganize filesystem locking to fix problems noticed by lockdep - refactor internal pstore APIs to make development and review easier: - improve error reporting - add kernel-doc structure and function comments - avoid insane argument passing by using a common record structure" * tag 'pstore-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits) pstore: Solve lockdep warning by moving inode locks pstore: Fix flags to enable dumps on powerpc pstore: Remove unused vmalloc.h in pmsg pstore: simplify write_user_compat() pstore: Remove write_buf() callback pstore: Replace arguments for write_buf_user() API pstore: Replace arguments for write_buf() API pstore: Replace arguments for erase() API pstore: Do not duplicate record metadata pstore: Allocate records on heap instead of stack pstore: Pass record contents instead of copying pstore: Always allocate buffer for decompression pstore: Replace arguments for write() API pstore: Replace arguments for read() API pstore: Switch pstore_mkfile to pass record pstore: Move record decompression to function pstore: Extract common arguments into structure pstore: Add kernel-doc for struct pstore_info pstore: Improve register_pstore() error reporting pstore: Avoid race in module unloading ...
Diffstat (limited to 'include')
-rw-r--r--include/linux/pstore.h156
1 files changed, 131 insertions, 25 deletions
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 0da29cae009b..e2233f50f428 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -30,7 +30,9 @@
#include <linux/time.h>
#include <linux/types.h>
-/* types */
+struct module;
+
+/* pstore record types (see fs/pstore/inode.c for filename templates) */
enum pstore_type_id {
PSTORE_TYPE_DMESG = 0,
PSTORE_TYPE_MCE = 1,
@@ -45,42 +47,146 @@ enum pstore_type_id {
PSTORE_TYPE_UNKNOWN = 255
};
-struct module;
+struct pstore_info;
+/**
+ * struct pstore_record - details of a pstore record entry
+ * @psi: pstore backend driver information
+ * @type: pstore record type
+ * @id: per-type unique identifier for record
+ * @time: timestamp of the record
+ * @buf: pointer to record contents
+ * @size: size of @buf
+ * @ecc_notice_size:
+ * ECC information for @buf
+ *
+ * Valid for PSTORE_TYPE_DMESG @type:
+ *
+ * @count: Oops count since boot
+ * @reason: kdump reason for notification
+ * @part: position in a multipart record
+ * @compressed: whether the buffer is compressed
+ *
+ */
+struct pstore_record {
+ struct pstore_info *psi;
+ enum pstore_type_id type;
+ u64 id;
+ struct timespec time;
+ char *buf;
+ ssize_t size;
+ ssize_t ecc_notice_size;
+ int count;
+ enum kmsg_dump_reason reason;
+ unsigned int part;
+ bool compressed;
+};
+
+/**
+ * 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.
+ *
+ * @record:
+ * pointer to record to populate. @buf should be allocated
+ * by the backend and filled. At least @type and @id should
+ * be populated, since these are used when creating pstorefs
+ * file names.
+ *
+ * Returns record size on success, zero when no more records are
+ * available, or negative on error.
+ *
+ * @write:
+ * A newly generated record needs to be written to backend storage.
+ *
+ * @record:
+ * pointer to record metadata. When @type is PSTORE_TYPE_DMESG,
+ * @buf will be pointing to the preallocated @psi.buf, since
+ * memory allocation may be broken during an Oops. Regardless,
+ * @buf must be proccesed or copied before returning. The
+ * backend is also expected to write @id with something that
+ 8 can help identify this record to a future @erase callback.
+ *
+ * Returns 0 on success, and non-zero on error.
+ *
+ * @write_user:
+ * Perform a frontend write to a backend record, using a specified
+ * buffer that is coming directly from userspace, instead of the
+ * @record @buf.
+ *
+ * @record: pointer to record metadata.
+ * @buf: pointer to userspace contents to write to backend
+ *
+ * Returns 0 on success, and non-zero on error.
+ *
+ * @erase:
+ * Delete a record from backend storage. Different backends
+ * identify records differently, so entire original record is
+ * passed back to assist in identification of what the backend
+ * should remove from storage.
+ *
+ * @record: pointer to record metadata.
+ *
+ * Returns 0 on success, and non-zero on error.
+ *
+ */
struct pstore_info {
struct module *owner;
char *name;
- spinlock_t buf_lock; /* serialize access to 'buf' */
+
+ spinlock_t buf_lock;
char *buf;
size_t bufsize;
- struct mutex read_mutex; /* serialize open/read/close */
+
+ struct mutex read_mutex;
+
int flags;
+ void *data;
+
int (*open)(struct pstore_info *psi);
int (*close)(struct pstore_info *psi);
- ssize_t (*read)(u64 *id, enum pstore_type_id *type,
- int *count, struct timespec *time, char **buf,
- bool *compressed, ssize_t *ecc_notice_size,
- struct pstore_info *psi);
- int (*write)(enum pstore_type_id type,
- enum kmsg_dump_reason reason, u64 *id,
- unsigned int part, int count, bool compressed,
- size_t size, struct pstore_info *psi);
- int (*write_buf)(enum pstore_type_id type,
- enum kmsg_dump_reason reason, u64 *id,
- unsigned int part, const char *buf, bool compressed,
- size_t size, struct pstore_info *psi);
- int (*write_buf_user)(enum pstore_type_id type,
- enum kmsg_dump_reason reason, u64 *id,
- unsigned int part, const char __user *buf,
- bool compressed, size_t size, struct pstore_info *psi);
- int (*erase)(enum pstore_type_id type, u64 id,
- int count, struct timespec time,
- struct pstore_info *psi);
- void *data;
+ ssize_t (*read)(struct pstore_record *record);
+ int (*write)(struct pstore_record *record);
+ int (*write_user)(struct pstore_record *record,
+ const char __user *buf);
+ int (*erase)(struct pstore_record *record);
};
+/* Supported frontends */
#define PSTORE_FLAGS_DMESG (1 << 0)
-#define PSTORE_FLAGS_FRAGILE PSTORE_FLAGS_DMESG
#define PSTORE_FLAGS_CONSOLE (1 << 1)
#define PSTORE_FLAGS_FTRACE (1 << 2)
#define PSTORE_FLAGS_PMSG (1 << 3)