Convert raw serialized_data to KHO serializeable pointer (KHOSER_PTR).
This series also takes care of resolving the bug with memfd of using
phys_to_virt before checking the args->serialized_data value.

Fixes: b3749f174d68 ("mm: memfd_luo: allow preserving memfd")
Signed-off-by: Tarun Sahu <[email protected]>
---
 include/linux/kho/abi/luo.h  |  5 +++--
 include/linux/liveupdate.h   |  4 ++--
 kernel/liveupdate/luo_file.c | 24 ++++++++++++------------
 mm/memfd_luo.c               | 18 +++++++++---------
 4 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/include/linux/kho/abi/luo.h b/include/linux/kho/abi/luo.h
index 288076de6d4a..d5b3b1c0fec1 100644
--- a/include/linux/kho/abi/luo.h
+++ b/include/linux/kho/abi/luo.h
@@ -59,6 +59,7 @@
 
 #include <linux/align.h>
 #include <linux/kho/abi/block.h>
+#include <linux/kho/abi/kexec_handover.h>
 #include <uapi/linux/liveupdate.h>
 
 /*
@@ -89,14 +90,14 @@ struct luo_ser {
 /**
  * struct luo_file_ser - Represents the serialized preserves files.
  * @compatible:  File handler compatible string.
- * @data:        Private data
+ * @serialized_data:  The serialized pointer union for this file
  * @token:       User provided token for this file
  *
  * If this structure is modified, `LUO_ABI_COMPATIBLE` must be updated.
  */
 struct luo_file_ser {
        char compatible[LIVEUPDATE_HNDL_COMPAT_LENGTH];
-       u64 data;
+       DECLARE_KHOSER_PTR(serialized_data, void *);
        u64 token;
 } __packed;
 
diff --git a/include/linux/liveupdate.h b/include/linux/liveupdate.h
index 88722e5caf02..480d638b7d18 100644
--- a/include/linux/liveupdate.h
+++ b/include/linux/liveupdate.h
@@ -33,7 +33,7 @@ struct file;
  * @file:             The file object. For retrieve: [OUT] The callback sets
  *                    this to the new file. For other ops: [IN] The caller sets
  *                    this to the file being operated on.
- * @serialized_data:  The opaque u64 handle, preserve/prepare/freeze may update
+ * @serialized_data:  The serialized pointer union, preserve/prepare/freeze 
may update
  *                    this field.
  * @private_data:     Private data for the file used to hold runtime state that
  *                    is not preserved. Set by the handler's .preserve()
@@ -47,7 +47,7 @@ struct liveupdate_file_op_args {
        struct liveupdate_file_handler *handler;
        int retrieve_status;
        struct file *file;
-       u64 serialized_data;
+       DECLARE_KHOSER_PTR(serialized_data, void *);
        void *private_data;
 };
 
diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c
index c39f96961a85..79cfa5201899 100644
--- a/kernel/liveupdate/luo_file.c
+++ b/kernel/liveupdate/luo_file.c
@@ -125,7 +125,7 @@ static DEFINE_XARRAY(luo_preserved_files);
  * @file:          Pointer to the kernel's &struct file that is being 
preserved.
  *                 This is NULL in the new kernel until the file is 
successfully
  *                 retrieved.
- * @serialized_data: The opaque u64 handle to the serialized state of the file.
+ * @serialized_data: The serialized pointer union to the serialized state of 
the file.
  *                 This handle is passed back to the handler's .freeze(),
  *                 .retrieve(), and .finish() callbacks, allowing it to track
  *                 and update its serialized state across phases.
@@ -161,7 +161,7 @@ static DEFINE_XARRAY(luo_preserved_files);
 struct luo_file {
        struct liveupdate_file_handler *fh;
        struct file *file;
-       u64 serialized_data;
+       DECLARE_KHOSER_PTR(serialized_data, void *);
        void *private_data;
        int retrieve_status;
        struct mutex mutex;
@@ -289,7 +289,7 @@ int luo_preserve_file(struct luo_file_set *file_set, u64 
token, int fd)
        if (err)
                goto err_kfree;
 
-       luo_file->serialized_data = args.serialized_data;
+       KHOSER_COPY_TYPESAFE(luo_file->serialized_data, args.serialized_data);
        luo_file->private_data = args.private_data;
        list_add_tail(&luo_file->list, &file_set->files_list);
        file_set->count++;
@@ -342,7 +342,7 @@ void luo_file_unpreserve_files(struct luo_file_set 
*file_set)
 
                args.handler = luo_file->fh;
                args.file = luo_file->file;
-               args.serialized_data = luo_file->serialized_data;
+               KHOSER_COPY_TYPESAFE(args.serialized_data, 
luo_file->serialized_data);
                args.private_data = luo_file->private_data;
                luo_file->fh->ops->unpreserve(&args);
                luo_flb_file_unpreserve(luo_file->fh);
@@ -375,12 +375,12 @@ static int luo_file_freeze_one(struct luo_file_set 
*file_set,
 
                args.handler = luo_file->fh;
                args.file = luo_file->file;
-               args.serialized_data = luo_file->serialized_data;
+               KHOSER_COPY_TYPESAFE(args.serialized_data, 
luo_file->serialized_data);
                args.private_data = luo_file->private_data;
 
                err = luo_file->fh->ops->freeze(&args);
                if (!err)
-                       luo_file->serialized_data = args.serialized_data;
+                       KHOSER_COPY_TYPESAFE(luo_file->serialized_data, 
args.serialized_data);
        }
 
        return err;
@@ -396,7 +396,7 @@ static void luo_file_unfreeze_one(struct luo_file_set 
*file_set,
 
                args.handler = luo_file->fh;
                args.file = luo_file->file;
-               args.serialized_data = luo_file->serialized_data;
+               KHOSER_COPY_TYPESAFE(args.serialized_data, 
luo_file->serialized_data);
                args.private_data = luo_file->private_data;
 
                luo_file->fh->ops->unfreeze(&args);
@@ -483,7 +483,7 @@ int luo_file_freeze(struct luo_file_set *file_set,
 
                strscpy(file_ser->compatible, luo_file->fh->compatible,
                        sizeof(file_ser->compatible));
-               file_ser->data = luo_file->serialized_data;
+               KHOSER_COPY_TYPESAFE(file_ser->serialized_data, 
luo_file->serialized_data);
                file_ser->token = luo_file->token;
        }
 
@@ -587,7 +587,7 @@ int luo_retrieve_file(struct luo_file_set *file_set, u64 
token,
        }
 
        args.handler = luo_file->fh;
-       args.serialized_data = luo_file->serialized_data;
+       KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data);
        err = luo_file->fh->ops->retrieve(&args);
        if (err) {
                /* Keep the error code for later use. */
@@ -621,7 +621,7 @@ static int luo_file_can_finish_one(struct luo_file_set 
*file_set,
 
                args.handler = luo_file->fh;
                args.file = luo_file->file;
-               args.serialized_data = luo_file->serialized_data;
+               KHOSER_COPY_TYPESAFE(args.serialized_data, 
luo_file->serialized_data);
                args.retrieve_status = luo_file->retrieve_status;
                can_finish = luo_file->fh->ops->can_finish(&args);
        }
@@ -638,7 +638,7 @@ static void luo_file_finish_one(struct luo_file_set 
*file_set,
 
        args.handler = luo_file->fh;
        args.file = luo_file->file;
-       args.serialized_data = luo_file->serialized_data;
+       KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data);
        args.retrieve_status = luo_file->retrieve_status;
 
        luo_file->fh->ops->finish(&args);
@@ -748,7 +748,7 @@ static int luo_file_deserialize_one(struct luo_file_set 
*file_set,
 
        luo_file->fh = fh;
        luo_file->file = NULL;
-       luo_file->serialized_data = ser->data;
+       KHOSER_COPY_TYPESAFE(luo_file->serialized_data, ser->serialized_data);
        luo_file->token = ser->token;
        mutex_init(&luo_file->mutex);
        list_add_tail(&luo_file->list, &file_set->files_list);
diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c
index 59de210bee5f..daf2c4c3da35 100644
--- a/mm/memfd_luo.c
+++ b/mm/memfd_luo.c
@@ -257,6 +257,7 @@ static void memfd_luo_unpreserve_folios(struct kho_vmalloc 
*kho_vmalloc,
 
 static int memfd_luo_preserve(struct liveupdate_file_op_args *args)
 {
+       DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *);
        struct inode *inode = file_inode(args->file);
        struct memfd_luo_folio_ser *folios_ser;
        struct memfd_luo_ser *ser;
@@ -309,7 +310,8 @@ static int memfd_luo_preserve(struct 
liveupdate_file_op_args *args)
        inode_unlock(inode);
 
        args->private_data = folios_ser;
-       args->serialized_data = virt_to_phys(ser);
+       KHOSER_STORE_PTR(sd, ser);
+       KHOSER_COPY_TYPEUNSAFE(args->serialized_data, sd);
 
        return 0;
 
@@ -325,11 +327,10 @@ static int memfd_luo_freeze(struct 
liveupdate_file_op_args *args)
 {
        struct memfd_luo_ser *ser;
 
-       if (WARN_ON_ONCE(!args->serialized_data))
+       ser = KHOSER_LOAD_PTR(args->serialized_data);
+       if (WARN_ON_ONCE(!ser))
                return -EINVAL;
 
-       ser = phys_to_virt(args->serialized_data);
-
        /*
         * The pos might have changed since prepare. Everything else stays the
         * same.
@@ -344,14 +345,13 @@ static void memfd_luo_unpreserve(struct 
liveupdate_file_op_args *args)
        struct inode *inode = file_inode(args->file);
        struct memfd_luo_ser *ser;
 
-       if (WARN_ON_ONCE(!args->serialized_data))
+       ser = KHOSER_LOAD_PTR(args->serialized_data);
+       if (WARN_ON_ONCE(!ser))
                return;
 
        inode_lock(inode);
        shmem_freeze(inode, false);
 
-       ser = phys_to_virt(args->serialized_data);
-
        memfd_luo_unpreserve_folios(&ser->folios, args->private_data,
                                    ser->nr_folios);
 
@@ -397,7 +397,7 @@ static void memfd_luo_finish(struct liveupdate_file_op_args 
*args)
        if (args->retrieve_status)
                return;
 
-       ser = phys_to_virt(args->serialized_data);
+       ser = KHOSER_LOAD_PTR(args->serialized_data);
        if (!ser)
                return;
 
@@ -522,7 +522,7 @@ static int memfd_luo_retrieve(struct 
liveupdate_file_op_args *args)
        struct file *file;
        int err;
 
-       ser = phys_to_virt(args->serialized_data);
+       ser = KHOSER_LOAD_PTR(args->serialized_data);
        if (!ser)
                return -EINVAL;
 
-- 
2.55.0.rc0.738.g0c8ab3ebcc-goog


Reply via email to