Merge tag 'liveupdate-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux

Pull liveupdate updates from Mike Rapoport:
 "Kexec Handover (KHO):

   - make memory preservation compatible with deferred initialization
     of the memory map

  Live Update Orchestrator (LUO):

   - add LIVEUPDATE_SESSION_GET_NAME ioctl and parameter verification
     for LIVEUPDATE_IOCTL_CREATE_SESSION ioctl

   - documentation updates for liveupdate=on command line option,
     systemd support and the current compatibility status

   - remove the fixed limits on the number of files that can be
     preserved within a single session, and the total number of
     sessions managed by the LUO

  Misc fixes:

   - reference count incoming File-Lifecycle-Bound (FLB) data so
     it cannot be freed while a subsystem is still using it

   - fixes for a TOCTOU race in luo_session_retrieve(), a use-
     after-free in the file finish and unpreserve paths, concurrent
     session mutations during reboot and serialization on
     preserve_context kexec

   - make sure ioctls for incoming LUO sessions are blocked for
     outgoing sessions and vice versa

   - make sure KHO scratch size is always aligned by
     CMA_MIN_ALIGNMENT_BYTES

   - fix memblock tests build issue introduced by KHO changes"

* tag 'liveupdate-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (36 commits)
  liveupdate: Document that retrieve failure is permanent
  docs: memfd_preservation: fix rendering of ABI documentation
  selftests/liveupdate: Add stress-files kexec test
  selftests/liveupdate: Add stress-sessions kexec test
  selftests/liveupdate: Test session and file limit removal
  liveupdate: Remove limit on the number of files per session
  liveupdate: Remove limit on the number of sessions
  liveupdate: defer session block allocation and physical address setting
  kho: add support for linked-block serialization
  liveupdate: Extract luo_session_deserialize_one helper
  liveupdate: Extract luo_file_deserialize_one helper
  liveupdate: register luo_ser as KHO subtree
  liveupdate: centralize state management into struct luo_ser
  liveupdate: avoid mixing cleanup guards with goto in luo_session_retrieve_fd
  liveupdate: change file_set->count type to u64 for type safety
  liveupdate: Remove unused ser field from struct luo_session
  liveupdate: fix u-a-f in luo_file_unpreserve_files() and luo_file_finish()
  liveupdate: block session mutations during reboot
  liveupdate: fix TOCTOU race in luo_session_retrieve()
  liveupdate: skip serialization for context-preserving kexec
  ...

1 files changed, 24 insertions, 1 deletions

diff --git a/include/uapi/linux/liveupdate.h b/include/uapi/linux/liveupdate.h
index 30bc66ee9436..4043d4038712 100644
--- a/include/uapi/linux/liveupdate.h
+++ b/include/uapi/linux/liveupdate.h
@@ -59,6 +59,7 @@ enum {
 	LIVEUPDATE_CMD_SESSION_PRESERVE_FD = LIVEUPDATE_CMD_SESSION_BASE,
 	LIVEUPDATE_CMD_SESSION_RETRIEVE_FD = 0x41,
 	LIVEUPDATE_CMD_SESSION_FINISH = 0x42,
+	LIVEUPDATE_CMD_SESSION_GET_NAME = 0x43,
 };
 
 /**
@@ -168,7 +169,9 @@ struct liveupdate_session_preserve_fd {
  * associated with the token and populates the @fd field with a new file
  * descriptor referencing the restored resource in the current (new) kernel.
  * This operation must be performed *before* signaling completion via
- * %LIVEUPDATE_IOCTL_FINISH.
+ * %LIVEUPDATE_IOCTL_FINISH. If a retrieve of a token fails, subsequent
+ * attempts to retrieve the token fail with the same error code. Failed
+ * retrieves are not retried.
  *
  * Return: 0 on success, negative error code on failure (e.g., invalid token).
  */
@@ -213,4 +216,24 @@ struct liveupdate_session_finish {
 #define LIVEUPDATE_SESSION_FINISH					\
 	_IO(LIVEUPDATE_IOCTL_TYPE, LIVEUPDATE_CMD_SESSION_FINISH)
 
+/**
+ * struct liveupdate_session_get_name - ioctl(LIVEUPDATE_SESSION_GET_NAME)
+ * @size:  Input; sizeof(struct liveupdate_session_get_name)
+ * @reserved: Input; Must be zero. Reserved for future use.
+ * @name:  Output; A null-terminated string with the full session name.
+ *
+ * Retrieves the full name of the session associated with this file descriptor.
+ * This is useful because the kernel may truncate the name shown in /proc.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+struct liveupdate_session_get_name {
+	__u32		size;
+	__u32		reserved;
+	__u8		name[LIVEUPDATE_SESSION_NAME_LENGTH];
+};
+
+#define LIVEUPDATE_SESSION_GET_NAME					\
+	_IO(LIVEUPDATE_IOCTL_TYPE, LIVEUPDATE_CMD_SESSION_GET_NAME)
+
 #endif /* _UAPI_LIVEUPDATE_H */