kho: rename fdt parameter to blob in kho_add/remove_subtree()

Since kho_add_subtree() now accepts arbitrary data blobs (not just FDTs),
rename the parameter from 'fdt' to 'blob' to better reflect its purpose. 
Apply the same rename to kho_remove_subtree() for consistency.

Also rename kho_debugfs_fdt_add() and kho_debugfs_fdt_remove() to
kho_debugfs_blob_add() and kho_debugfs_blob_remove() respectively, with
the same parameter rename from 'fdt' to 'blob'.

Link: https://lore.kernel.org/20260316-kho-v9-2-ed6dcd951988@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

3 files changed, 38 insertions, 36 deletions

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index 8cc25e29ff91..711b6c3376e7 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -724,13 +724,13 @@ err_disable_kho:
 }
 
 /**
- * kho_add_subtree - record the physical address of a sub FDT in KHO root tree.
+ * kho_add_subtree - record the physical address of a sub blob in KHO root tree.
  * @name: name of the sub tree.
- * @fdt: the sub tree blob.
+ * @blob: the sub tree blob.
  * @size: size of the blob in bytes.
  *
  * Creates a new child node named @name in KHO root FDT and records
- * the physical address of @fdt. The pages of @fdt must also be preserved
+ * the physical address of @blob. The pages of @blob must also be preserved
  * by KHO for the new kernel to retrieve it after kexec.
  *
  * A debugfs blob entry is also created at
@@ -739,9 +739,9 @@ err_disable_kho:
  *
  * Return: 0 on success, error code on failure
  */
-int kho_add_subtree(const char *name, void *fdt, size_t size)
+int kho_add_subtree(const char *name, void *blob, size_t size)
 {
-	phys_addr_t phys = virt_to_phys(fdt);
+	phys_addr_t phys = virt_to_phys(blob);
 	void *root_fdt = kho_out.fdt;
 	int err = -ENOMEM;
 	int off, fdt_err;
@@ -764,7 +764,8 @@ int kho_add_subtree(const char *name, void *fdt, size_t size)
 	if (err < 0)
 		goto out_pack;
 
-	WARN_ON_ONCE(kho_debugfs_fdt_add(&kho_out.dbg, name, fdt, size, false));
+	WARN_ON_ONCE(kho_debugfs_blob_add(&kho_out.dbg, name, blob,
+					  size, false));
 
 out_pack:
 	fdt_pack(root_fdt);
@@ -773,9 +774,9 @@ out_pack:
 }
 EXPORT_SYMBOL_GPL(kho_add_subtree);
 
-void kho_remove_subtree(void *fdt)
+void kho_remove_subtree(void *blob)
 {
-	phys_addr_t target_phys = virt_to_phys(fdt);
+	phys_addr_t target_phys = virt_to_phys(blob);
 	void *root_fdt = kho_out.fdt;
 	int off;
 	int err;
@@ -797,7 +798,7 @@ void kho_remove_subtree(void *fdt)
 
 		if ((phys_addr_t)*val == target_phys) {
 			fdt_del_node(root_fdt, off);
-			kho_debugfs_fdt_remove(&kho_out.dbg, fdt);
+			kho_debugfs_blob_remove(&kho_out.dbg, blob);
 			break;
 		}
 	}
@@ -1293,11 +1294,11 @@ bool is_kho_boot(void)
 EXPORT_SYMBOL_GPL(is_kho_boot);
 
 /**
- * kho_retrieve_subtree - retrieve a preserved sub FDT by its name.
- * @name: the name of the sub FDT passed to kho_add_subtree().
- * @phys: if found, the physical address of the sub FDT is stored in @phys.
+ * kho_retrieve_subtree - retrieve a preserved sub blob by its name.
+ * @name: the name of the sub blob passed to kho_add_subtree().
+ * @phys: if found, the physical address of the sub blob is stored in @phys.
  *
- * Retrieve a preserved sub FDT named @name and store its physical
+ * Retrieve a preserved sub blob named @name and store its physical
  * address in @phys.
  *
  * Return: 0 on success, error code on failure
@@ -1431,9 +1432,9 @@ static __init int kho_init(void)
 			init_cma_reserved_pageblock(pfn_to_page(pfn));
 	}
 
-	WARN_ON_ONCE(kho_debugfs_fdt_add(&kho_out.dbg, "fdt",
-					 kho_out.fdt,
-					 fdt_totalsize(kho_out.fdt), true));
+	WARN_ON_ONCE(kho_debugfs_blob_add(&kho_out.dbg, "fdt",
+					  kho_out.fdt,
+					  fdt_totalsize(kho_out.fdt), true));
 
 	return 0;
 
diff --git a/kernel/liveupdate/kexec_handover_debugfs.c b/kernel/liveupdate/kexec_handover_debugfs.c
index ca0153736af1..cab923e4f5c8 100644
--- a/kernel/liveupdate/kexec_handover_debugfs.c
+++ b/kernel/liveupdate/kexec_handover_debugfs.c
@@ -24,8 +24,9 @@ struct fdt_debugfs {
 	struct dentry *file;
 };
 
-static int __kho_debugfs_fdt_add(struct list_head *list, struct dentry *dir,
-				 const char *name, const void *fdt, size_t size)
+static int __kho_debugfs_blob_add(struct list_head *list, struct dentry *dir,
+				  const char *name, const void *blob,
+				  size_t size)
 {
 	struct fdt_debugfs *f;
 	struct dentry *file;
@@ -34,7 +35,7 @@ static int __kho_debugfs_fdt_add(struct list_head *list, struct dentry *dir,
 	if (!f)
 		return -ENOMEM;
 
-	f->wrapper.data = (void *)fdt;
+	f->wrapper.data = (void *)blob;
 	f->wrapper.size = size;
 
 	file = debugfs_create_blob(name, 0400, dir, &f->wrapper);
@@ -49,8 +50,8 @@ static int __kho_debugfs_fdt_add(struct list_head *list, struct dentry *dir,
 	return 0;
 }
 
-int kho_debugfs_fdt_add(struct kho_debugfs *dbg, const char *name,
-			const void *fdt, size_t size, bool root)
+int kho_debugfs_blob_add(struct kho_debugfs *dbg, const char *name,
+			 const void *blob, size_t size, bool root)
 {
 	struct dentry *dir;
 
@@ -59,15 +60,15 @@ int kho_debugfs_fdt_add(struct kho_debugfs *dbg, const char *name,
 	else
 		dir = dbg->sub_fdt_dir;
 
-	return __kho_debugfs_fdt_add(&dbg->fdt_list, dir, name, fdt, size);
+	return __kho_debugfs_blob_add(&dbg->fdt_list, dir, name, blob, size);
 }
 
-void kho_debugfs_fdt_remove(struct kho_debugfs *dbg, void *fdt)
+void kho_debugfs_blob_remove(struct kho_debugfs *dbg, void *blob)
 {
 	struct fdt_debugfs *ff;
 
 	list_for_each_entry(ff, &dbg->fdt_list, list) {
-		if (ff->wrapper.data == fdt) {
+		if (ff->wrapper.data == blob) {
 			debugfs_remove(ff->file);
 			list_del(&ff->list);
 			kfree(ff);
@@ -113,8 +114,8 @@ __init void kho_in_debugfs_init(struct kho_debugfs *dbg, const void *fdt)
 		goto err_rmdir;
 	}
 
-	err = __kho_debugfs_fdt_add(&dbg->fdt_list, dir, "fdt", fdt,
-				    fdt_totalsize(fdt));
+	err = __kho_debugfs_blob_add(&dbg->fdt_list, dir, "fdt", fdt,
+				     fdt_totalsize(fdt));
 	if (err)
 		goto err_rmdir;
 
@@ -133,8 +134,8 @@ __init void kho_in_debugfs_init(struct kho_debugfs *dbg, const void *fdt)
 			continue;
 		}
 		sub_fdt = phys_to_virt(*fdt_phys);
-		err = __kho_debugfs_fdt_add(&dbg->fdt_list, sub_fdt_dir, name,
-					    sub_fdt, fdt_totalsize(sub_fdt));
+		err = __kho_debugfs_blob_add(&dbg->fdt_list, sub_fdt_dir, name,
+					     sub_fdt, fdt_totalsize(sub_fdt));
 		if (err) {
 			pr_warn("failed to add fdt %s to debugfs: %pe\n", name,
 				ERR_PTR(err));
diff --git a/kernel/liveupdate/kexec_handover_internal.h b/kernel/liveupdate/kexec_handover_internal.h
index 2a28cb8db9b0..0399ff107775 100644
--- a/kernel/liveupdate/kexec_handover_internal.h
+++ b/kernel/liveupdate/kexec_handover_internal.h
@@ -26,19 +26,19 @@ extern unsigned int kho_scratch_cnt;
 int kho_debugfs_init(void);
 void kho_in_debugfs_init(struct kho_debugfs *dbg, const void *fdt);
 int kho_out_debugfs_init(struct kho_debugfs *dbg);
-int kho_debugfs_fdt_add(struct kho_debugfs *dbg, const char *name,
-			const void *fdt, size_t size, bool root);
-void kho_debugfs_fdt_remove(struct kho_debugfs *dbg, void *fdt);
+int kho_debugfs_blob_add(struct kho_debugfs *dbg, const char *name,
+			 const void *blob, size_t size, bool root);
+void kho_debugfs_blob_remove(struct kho_debugfs *dbg, void *blob);
 #else
 static inline int kho_debugfs_init(void) { return 0; }
 static inline void kho_in_debugfs_init(struct kho_debugfs *dbg,
 				       const void *fdt) { }
 static inline int kho_out_debugfs_init(struct kho_debugfs *dbg) { return 0; }
-static inline int kho_debugfs_fdt_add(struct kho_debugfs *dbg, const char *name,
-				      const void *fdt, size_t size,
-				      bool root) { return 0; }
-static inline void kho_debugfs_fdt_remove(struct kho_debugfs *dbg,
-					  void *fdt) { }
+static inline int kho_debugfs_blob_add(struct kho_debugfs *dbg,
+				       const char *name, const void *blob,
+				       size_t size, bool root) { return 0; }
+static inline void kho_debugfs_blob_remove(struct kho_debugfs *dbg,
+					   void *blob) { }
 #endif /* CONFIG_KEXEC_HANDOVER_DEBUGFS */
 
 #ifdef CONFIG_KEXEC_HANDOVER_DEBUG