diff options
| -rw-r--r-- | include/linux/liveupdate.h | 22 | ||||
| -rw-r--r-- | kernel/liveupdate/kexec_handover.c | 7 | ||||
| -rw-r--r-- | kernel/liveupdate/luo_file.c | 69 | ||||
| -rw-r--r-- | kernel/liveupdate/luo_internal.h | 17 |
4 files changed, 115 insertions, 0 deletions
diff --git a/include/linux/liveupdate.h b/include/linux/liveupdate.h index 63ea5417de84..6051abc0612c 100644 --- a/include/linux/liveupdate.h +++ b/include/linux/liveupdate.h @@ -25,6 +25,7 @@ struct file; /** * struct liveupdate_file_op_args - Arguments for file operation callbacks. * @handler: The file handler being called. + * @session: The session this file belongs to. * @retrieve_status: The retrieve status for the 'can_finish / finish' * operation. A value of 0 means the retrieve has not been * attempted, a positive value means the retrieve was @@ -45,6 +46,7 @@ struct file; */ struct liveupdate_file_op_args { struct liveupdate_file_handler *handler; + struct liveupdate_session *session; int retrieve_status; struct file *file; u64 serialized_data; @@ -247,6 +249,14 @@ void liveupdate_flb_put_incoming(struct liveupdate_flb *flb); int liveupdate_flb_get_outgoing(struct liveupdate_flb *flb, void **objp); void liveupdate_flb_put_outgoing(struct liveupdate_flb *flb); +/* kernel can internally retrieve files */ +int liveupdate_get_file_incoming(struct liveupdate_session *s, u64 token, + struct file **filep); + +/* Get a token for an outgoing file, or -ENOENT if file is not preserved */ +int liveupdate_get_token_outgoing(struct liveupdate_session *s, + struct file *file, u64 *tokenp); + #else /* CONFIG_LIVEUPDATE */ static inline bool liveupdate_enabled(void) @@ -299,5 +309,17 @@ static inline void liveupdate_flb_put_outgoing(struct liveupdate_flb *flb) { } +static inline int liveupdate_get_file_incoming(struct liveupdate_session *s, + u64 token, struct file **filep) +{ + return -EOPNOTSUPP; +} + +static inline int liveupdate_get_token_outgoing(struct liveupdate_session *s, + struct file *file, u64 *tokenp) +{ + return -EOPNOTSUPP; +} + #endif /* CONFIG_LIVEUPDATE */ #endif /* _LINUX_LIVEUPDATE_H */ diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 7c4d86daf86d..3c87c2a3d6f0 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -12,6 +12,7 @@ #include <linux/cleanup.h> #include <linux/cma.h> +#include <linux/crash_dump.h> #include <linux/kmemleak.h> #include <linux/count_zeros.h> #include <linux/kasan.h> @@ -1939,6 +1940,12 @@ err: void __init kho_memory_init(void) { + if (is_kdump_kernel()) { + kho_enable = false; + pr_info("disabled in the kdump kernel\n"); + return; + } + if (kho_in.scratch_phys) kho_mem_retrieve(); else diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c index c39f96961a85..dbae0715220b 100644 --- a/kernel/liveupdate/luo_file.c +++ b/kernel/liveupdate/luo_file.c @@ -284,6 +284,7 @@ int luo_preserve_file(struct luo_file_set *file_set, u64 token, int fd) mutex_init(&luo_file->mutex); args.handler = fh; + args.session = luo_session_from_file_set(file_set); args.file = file; err = fh->ops->preserve(&args); if (err) @@ -341,6 +342,7 @@ void luo_file_unpreserve_files(struct luo_file_set *file_set) struct luo_file, list); args.handler = luo_file->fh; + args.session = luo_session_from_file_set(file_set); args.file = luo_file->file; args.serialized_data = luo_file->serialized_data; args.private_data = luo_file->private_data; @@ -374,6 +376,7 @@ static int luo_file_freeze_one(struct luo_file_set *file_set, struct liveupdate_file_op_args args = {0}; args.handler = luo_file->fh; + args.session = luo_session_from_file_set(file_set); args.file = luo_file->file; args.serialized_data = luo_file->serialized_data; args.private_data = luo_file->private_data; @@ -395,6 +398,7 @@ static void luo_file_unfreeze_one(struct luo_file_set *file_set, struct liveupdate_file_op_args args = {0}; args.handler = luo_file->fh; + args.session = luo_session_from_file_set(file_set); args.file = luo_file->file; args.serialized_data = luo_file->serialized_data; args.private_data = luo_file->private_data; @@ -587,6 +591,7 @@ int luo_retrieve_file(struct luo_file_set *file_set, u64 token, } args.handler = luo_file->fh; + args.session = luo_session_from_file_set(file_set); args.serialized_data = luo_file->serialized_data; err = luo_file->fh->ops->retrieve(&args); if (err) { @@ -620,6 +625,7 @@ static int luo_file_can_finish_one(struct luo_file_set *file_set, struct liveupdate_file_op_args args = {0}; args.handler = luo_file->fh; + args.session = luo_session_from_file_set(file_set); args.file = luo_file->file; args.serialized_data = luo_file->serialized_data; args.retrieve_status = luo_file->retrieve_status; @@ -637,6 +643,7 @@ static void luo_file_finish_one(struct luo_file_set *file_set, guard(mutex)(&luo_file->mutex); args.handler = luo_file->fh; + args.session = luo_session_from_file_set(file_set); args.file = luo_file->file; args.serialized_data = luo_file->serialized_data; args.retrieve_status = luo_file->retrieve_status; @@ -926,3 +933,65 @@ void liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh) luo_flb_unregister_all(fh); list_del(&ACCESS_PRIVATE(fh, list)); } + +/** + * liveupdate_get_token_outgoing - Get the token for a preserved file. + * @s: The outgoing liveupdate session. + * @file: The file object to search for. + * @tokenp: Output parameter for the found token. + * + * Searches the list of preserved files in an outgoing session for a matching + * file object. If found, the corresponding user-provided token is returned. + * + * This function is intended for in-kernel callers that need to correlate a + * file with its liveupdate token. + * + * Context: It must be called with session mutex acquired. + * Return: 0 on success, -ENOENT if the file is not preserved in this session. + */ +int liveupdate_get_token_outgoing(struct liveupdate_session *s, + struct file *file, u64 *tokenp) +{ + struct luo_file_set *file_set = luo_file_set_from_session_locked(s); + struct luo_file *luo_file; + int err = -ENOENT; + + list_for_each_entry(luo_file, &file_set->files_list, list) { + if (luo_file->file == file) { + if (tokenp) + *tokenp = luo_file->token; + err = 0; + break; + } + } + + return err; +} +EXPORT_SYMBOL_GPL(liveupdate_get_token_outgoing); + +/** + * liveupdate_get_file_incoming - Retrieves a preserved file for in-kernel use. + * @s: The incoming liveupdate session (restored from the previous kernel). + * @token: The unique token identifying the file to retrieve. + * @filep: On success, this will be populated with a pointer to the retrieved + * 'struct file'. + * + * Provides a kernel-internal API for other subsystems to retrieve their + * preserved files after a live update. This function is a simple wrapper + * around luo_retrieve_file(), allowing callers to find a file by its token. + * + * The caller receives a new reference to the file and must call fput() when it + * is no longer needed. The file's lifetime is managed by LUO and any userspace + * file descriptors. + * + * Context: It must be called with session mutex acquired of a restored session. + * Return: 0 on success. Returns -ENOENT if no file with the matching token is + * found, or any other negative errno on failure. + */ +int liveupdate_get_file_incoming(struct liveupdate_session *s, u64 token, + struct file **filep) +{ + return luo_retrieve_file(luo_file_set_from_session_locked(s), + token, filep); +} +EXPORT_SYMBOL_GPL(liveupdate_get_file_incoming); diff --git a/kernel/liveupdate/luo_internal.h b/kernel/liveupdate/luo_internal.h index 64879ffe7378..dac6644bfb18 100644 --- a/kernel/liveupdate/luo_internal.h +++ b/kernel/liveupdate/luo_internal.h @@ -77,6 +77,23 @@ struct luo_session { extern struct rw_semaphore luo_register_rwlock; +static inline struct liveupdate_session *luo_session_from_file_set(struct luo_file_set *file_set) +{ + struct luo_session *session; + + session = container_of(file_set, struct luo_session, file_set); + + return (struct liveupdate_session *)session; +} + +static inline struct luo_file_set *luo_file_set_from_session_locked(struct liveupdate_session *s) +{ + struct luo_session *session = (struct luo_session *)s; + + lockdep_assert_held(&session->mutex); + return &session->file_set; +} + int luo_session_create(const char *name, struct file **filep); int luo_session_retrieve(const char *name, struct file **filep); void __init luo_session_setup_outgoing(u64 *sessions_pa); |