From: Mike Rapoport <rppt@kernel.org>
To: Breno Leitao <leitao@debian.org>
Cc: Alexander Graf <graf@amazon.com>,
Pasha Tatashin <pasha.tatashin@soleen.com>,
Pratyush Yadav <pratyush@kernel.org>,
linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
linux-mm@kvack.org, usamaarif642@gmail.com,
SeongJae Park <sj@kernel.org>,
kernel-team@meta.com
Subject: Re: [PATCH v7 2/6] kho: rename fdt parameter to blob in kho_add/remove_subtree()
Date: Mon, 9 Mar 2026 09:58:02 +0200 [thread overview]
Message-ID: <aa59irg2P-sejKO5@kernel.org> (raw)
In-Reply-To: <20260306-kho-v7-2-404d14c188bb@debian.org>
On Fri, Mar 06, 2026 at 04:39:21AM -0800, Breno Leitao wrote:
> 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'.
>
> Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> include/linux/kexec_handover.h | 8 ++++----
> kernel/liveupdate/kexec_handover.c | 25 +++++++++++++------------
> kernel/liveupdate/kexec_handover_debugfs.c | 25 +++++++++++++------------
> kernel/liveupdate/kexec_handover_internal.h | 16 ++++++++--------
> 4 files changed, 38 insertions(+), 36 deletions(-)
>
> diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h
> index abb1d324f42d0..0666cf298c7f4 100644
> --- a/include/linux/kexec_handover.h
> +++ b/include/linux/kexec_handover.h
> @@ -32,8 +32,8 @@ void kho_restore_free(void *mem);
> struct folio *kho_restore_folio(phys_addr_t phys);
> struct page *kho_restore_pages(phys_addr_t phys, unsigned long nr_pages);
> void *kho_restore_vmalloc(const struct kho_vmalloc *preservation);
> -int kho_add_subtree(const char *name, void *fdt, size_t size);
> -void kho_remove_subtree(void *fdt);
> +int kho_add_subtree(const char *name, void *blob, size_t size);
> +void kho_remove_subtree(void *blob);
> int kho_retrieve_subtree(const char *name, phys_addr_t *phys);
>
> void kho_memory_init(void);
> @@ -97,12 +97,12 @@ static inline void *kho_restore_vmalloc(const struct kho_vmalloc *preservation)
> return NULL;
> }
>
> -static inline int kho_add_subtree(const char *name, void *fdt, size_t size)
> +static inline int kho_add_subtree(const char *name, void *blob, size_t size)
> {
> return -EOPNOTSUPP;
> }
>
> -static inline void kho_remove_subtree(void *fdt) { }
> +static inline void kho_remove_subtree(void *blob) { }
>
> static inline int kho_retrieve_subtree(const char *name, phys_addr_t *phys)
> {
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index 55bdc5d2d1929..ebaf3104c36ab 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -749,13 +749,13 @@ static void __init kho_reserve_scratch(void)
> }
>
> /**
> - * 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
> @@ -764,9 +764,9 @@ static void __init kho_reserve_scratch(void)
> *
> * 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;
> @@ -789,7 +789,8 @@ 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);
> @@ -798,9 +799,9 @@ int kho_add_subtree(const char *name, void *fdt, size_t size)
> }
> 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;
> @@ -822,7 +823,7 @@ 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;
> }
> }
> @@ -1452,9 +1453,9 @@ static __init int kho_init(void)
> return 0;
> }
>
> - 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 b5a1e09ca8f14..7a100f2bf3947 100644
> --- a/kernel/liveupdate/kexec_handover_debugfs.c
> +++ b/kernel/liveupdate/kexec_handover_debugfs.c
> @@ -23,8 +23,9 @@ 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;
> @@ -33,7 +34,7 @@ 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);
> @@ -48,8 +49,8 @@ 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;
>
> @@ -58,15 +59,15 @@ 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);
> @@ -112,8 +113,8 @@ __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;
>
> @@ -132,8 +133,8 @@ __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 2a28cb8db9b0a..0399ff1077750 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
>
> --
> 2.47.3
>
>
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2026-03-09 7:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-06 12:39 [PATCH v7 0/6] kho: history: track previous kernel version and kexec boot count Breno Leitao
2026-03-06 12:39 ` [PATCH v7 1/6] kho: add size parameter to kho_add_subtree() Breno Leitao
2026-03-06 12:39 ` [PATCH v7 2/6] kho: rename fdt parameter to blob in kho_add/remove_subtree() Breno Leitao
2026-03-09 7:58 ` Mike Rapoport [this message]
2026-03-06 12:39 ` [PATCH v7 3/6] kho: persist blob size in KHO FDT Breno Leitao
2026-03-09 8:04 ` Mike Rapoport
2026-03-06 12:39 ` [PATCH v7 4/6] kho: fix kho_in_debugfs_init() to handle non-FDT blobs Breno Leitao
2026-03-09 8:22 ` Mike Rapoport
2026-03-09 13:01 ` Breno Leitao
2026-03-06 12:39 ` [PATCH v7 5/6] kho: kexec-metadata: track previous kernel chain Breno Leitao
2026-03-06 12:39 ` [PATCH v7 6/6] kho: document kexec-metadata tracking feature Breno Leitao
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