Currently, the FDT folio is preserved inside __kho_finalize(). If the user performs multiple finalize/abort cycles, kho_preserve_folio() is called repeatedly for the same FDT folio. Since the FDT folio is allocated once during kho_init(), it should be marked for preservation at the same time. Move the preservation call to kho_init() to align the preservation state with the object's lifecycle and simplify the finalize path. Also, pre-zero the FDT tree so we do not expose random bits to the user and to the next kernel by using the new kho_alloc_preserve() api. Signed-off-by: Pasha Tatashin Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Pratyush Yadav --- kernel/liveupdate/kexec_handover.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 5c5c9c46fe92..704e91418214 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -1251,10 +1251,6 @@ static int __kho_finalize(void) if (err) goto abort; - err = kho_preserve_folio(virt_to_folio(kho_out.fdt)); - if (err) - goto abort; - err = kho_mem_serialize(&kho_out); if (err) goto abort; @@ -1384,19 +1380,17 @@ EXPORT_SYMBOL_GPL(kho_retrieve_subtree); static __init int kho_init(void) { - int err = 0; const void *fdt = kho_get_fdt(); - struct page *fdt_page; + int err = 0; if (!kho_enable) return 0; - fdt_page = alloc_page(GFP_KERNEL); - if (!fdt_page) { - err = -ENOMEM; + kho_out.fdt = kho_alloc_preserve(PAGE_SIZE); + if (IS_ERR(kho_out.fdt)) { + err = PTR_ERR(kho_out.fdt); goto err_free_scratch; } - kho_out.fdt = page_to_virt(fdt_page); err = kho_debugfs_init(); if (err) @@ -1424,9 +1418,9 @@ static __init int kho_init(void) return 0; err_free_fdt: - put_page(fdt_page); - kho_out.fdt = NULL; + kho_unpreserve_free(kho_out.fdt); err_free_scratch: + kho_out.fdt = NULL; for (int i = 0; i < kho_scratch_cnt; i++) { void *start = __va(kho_scratch[i].addr); void *end = start + kho_scratch[i].size; -- 2.52.0.rc1.455.g30608eb744-goog