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charset="UTF-8" Precede each serialized session entry in the LUO session KHO block set with struct kho_ser_hdr via DECLARE_KHO_SER so future session features can append fields to struct luo_session_ser without breaking compatibility between adjacent kernels. Size session block-set entries using kho_ser_size(luo_session_ser), initialize each entry feature header during luo_session_serialize(), and validate the incoming feature header in luo_session_deserialize_one() before accessing the struct luo_session_ser payload. Signed-off-by: Tarun Sahu --- include/linux/kho/abi/luo.h | 6 +++--- kernel/liveupdate/luo_session.c | 38 ++++++++++++++++++++++----------- 2 files changed, 29 insertions(+), 15 deletions(-) diff --git a/include/linux/kho/abi/luo.h b/include/linux/kho/abi/luo.h index dfa7ea434d0d..425c52c494f1 100644 --- a/include/linux/kho/abi/luo.h +++ b/include/linux/kho/abi/luo.h @@ -132,15 +132,15 @@ static_assert(!IS_ENABLED(CONFIG_64BIT) || * between kernels via Kexec Handover. An array of these structures (one per * session) is created and passed to the target kernel, allowing it to * reconstruct the session context. + * + * Preceded by &struct kho_ser_hdr. */ struct luo_session_ser { char name[LIVEUPDATE_SESSION_NAME_LENGTH]; DECLARE_KHOSER_PTR(file_set_ser, struct luo_file_set_ser *); }; -static_assert(sizeof(struct luo_session_ser) == 72); -static_assert(!IS_ENABLED(CONFIG_64BIT) || - __alignof__(struct luo_session_ser) == 8); +DECLARE_KHO_SER(luo_session_ser, 72, 0, 0); /* The max size is set so it can be reliably used during in serialization */ #define LIVEUPDATE_FLB_COMPAT_LENGTH 48 diff --git a/kernel/liveupdate/luo_session.c b/kernel/liveupdate/luo_session.c index df667fe15fb2..641bd67ce76e 100644 --- a/kernel/liveupdate/luo_session.c +++ b/kernel/liveupdate/luo_session.c @@ -131,7 +131,7 @@ struct luo_session_global { struct luo_session_header outgoing; }; -#define LUO_SESSION_SER_SIZE (sizeof(struct luo_session_ser) + \ +#define LUO_SESSION_SER_SIZE (kho_ser_size(luo_session_ser) + \ sizeof(struct luo_file_set_ser)) static struct luo_session_global luo_session_global = { @@ -557,23 +557,33 @@ int __init luo_session_setup_incoming(u64 sessions_pa) return 0; } -static struct luo_session_ser *luo_session_ser_init(void *mem) +static struct luo_session_ser * +luo_session_ser_init(DECLARE_KHO_SER_HDR(luo_session_ser, *fhdr)) { struct luo_file_set_ser *file_set_ser; - struct luo_session_ser *ser = mem; + struct luo_session_ser *ser; + + kho_ser_init(fhdr, luo_session_ser); + file_set_ser = (void *)fhdr + kho_ser_size(luo_session_ser); - file_set_ser = mem + sizeof(struct luo_session_ser); + ser = kho_ser_payload(fhdr, luo_session_ser); KHOSER_STORE_PTR(ser->file_set_ser, file_set_ser); return ser; } static int luo_session_deserialize_one(struct luo_session_header *sh, - struct luo_session_ser *ser) + DECLARE_KHO_SER_HDR(luo_session_ser, *fhdr)) { + struct luo_session_ser *ser; struct luo_session *session; int err; + err = kho_ser_validate(fhdr, luo_session_ser); + if (err) + return err; + + ser = kho_ser_payload(fhdr, luo_session_ser); session = luo_session_alloc(ser->name); if (IS_ERR(session)) { pr_warn("Failed to allocate session [%.*s] during deserialization %pe\n", @@ -606,7 +616,7 @@ int luo_session_deserialize(void) { struct luo_session_header *sh = &luo_session_global.incoming; static bool is_deserialized; - struct luo_session_ser *ser; + DECLARE_KHO_SER_HDR(luo_session_ser, *fhdr); struct kho_block_set_it it; static int saved_err; int err; @@ -635,8 +645,8 @@ int luo_session_deserialize(void) * reliably reset devices and reclaim memory. */ kho_block_set_it_init(&it, &sh->block_set); - while ((ser = kho_block_set_it_read_entry(&it))) { - err = luo_session_deserialize_one(sh, ser); + while ((fhdr = kho_block_set_it_read_entry(&it))) { + err = luo_session_deserialize_one(sh, fhdr); if (err) goto save_err; } @@ -665,15 +675,17 @@ int luo_session_serialize(void) kho_block_set_it_init(&it, &sh->block_set); list_for_each_entry(session, &sh->list, list) { - struct luo_session_ser *ser = kho_block_set_it_reserve_entry(&it); + DECLARE_KHO_SER_HDR(luo_session_ser, *fhdr) = + kho_block_set_it_reserve_entry(&it); + struct luo_session_ser *ser; /* This should not fail normally as blocks were pre-allocated */ - if (WARN_ON_ONCE(!ser)) { + if (WARN_ON_ONCE(!fhdr)) { err = -ENOSPC; goto err_undo; } - ser = luo_session_ser_init(ser); + ser = luo_session_ser_init(fhdr); err = luo_session_freeze_one(session, ser); if (err) { kho_block_set_it_prev(&it); @@ -691,7 +703,9 @@ int luo_session_serialize(void) err_undo: list_for_each_entry_continue_reverse(session, &sh->list, list) { - struct luo_session_ser *ser = kho_block_set_it_prev(&it); + DECLARE_KHO_SER_HDR(luo_session_ser, *fhdr) = + kho_block_set_it_prev(&it); + struct luo_session_ser *ser = kho_ser_payload(fhdr, luo_session_ser); luo_session_unfreeze_one(session, ser); memset(ser->name, 0, sizeof(ser->name)); -- 2.56.0.506.g506a7eabc5-goog