From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7C3C7D25959 for ; Tue, 27 Jan 2026 07:23:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DA3356B0088; Tue, 27 Jan 2026 02:23:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D26C76B0089; Tue, 27 Jan 2026 02:23:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C323F6B008A; Tue, 27 Jan 2026 02:23:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id B2FF56B0088 for ; Tue, 27 Jan 2026 02:23:41 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 65B6E13BED2 for ; Tue, 27 Jan 2026 07:23:41 +0000 (UTC) X-FDA: 84376903842.10.756325E Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf06.hostedemail.com (Postfix) with ESMTP id A2A92180007 for ; Tue, 27 Jan 2026 07:23:39 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=G4bBJQeU; spf=pass (imf06.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1769498619; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=LS8aWoAwuUZfXKGJJtyYD5Ry6YFS4Hs0JmhcUrHlK/s=; b=7Yiv1rzHVmpnIlGojfxBnkrCljY0x6RKoy7fXTMMPHZcX+TRz6RZyTYHK3SH4R0NoTfLfd CF9Acs4lnK3lvrQpvGRDgDEMwfEIs/4uBeZWO/8jG/JYdeIW9rdoPUVdjM7c1ItoLZu09O itaWvAKOx1poBO9nZV2lAxmaMJUPIec= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=G4bBJQeU; spf=pass (imf06.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1769498619; a=rsa-sha256; cv=none; b=NsWU0CXYUB7bT6x7PE4Gj1JD618uJYDLV1OIyOwMhPyFMgW44i+NnN9rxBGzLZxNy3HVPr XFICkGY0DO5NlGGx/WjqXhf0Q+9vTxfVH1L3E/jEKG92Uaai43fCzgMVog+NRvgL2qhA/8 mZEjBbBt6QL65v+fnBORE8qXslY2xP4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 942BF43F89; Tue, 27 Jan 2026 07:23:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F0FDC116C6; Tue, 27 Jan 2026 07:23:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769498618; bh=wKc6TL0A4RPyPSsNR6BFVNJfOo7cACM6wopJvwkAz0g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G4bBJQeU/o9hOCFqmG0i2rEDHAXUQpCc0MJKYS6Y5c/RUILsdmi8lxJVvxAa+Cjl6 L0Fkyp58vRmqs9H7LMt7ccQ+bhA0PGlobSQELyJcEpBhrnS9bcNhXDAOOySeHifhwh oDWSNMFxC1W1odL6Lv2avlJWJDfi1sEh9IgV+zqZAH3hKAD3zzoNijv8EfZST1APKh c2cbZvdVdf5wtPe+E+4Sg4BWBhIc1AJn5O9Dhz9u3+/MsiLxHi5Mjd/fPCSoZe7Vip X5DbMcjA5hw0brxwPZ8L7gLZpTpER20rkSCVGNiFynFI/cjdd9wpJkSWViWwE4dk4b 6AzxEMzqK1u9w== Date: Tue, 27 Jan 2026 09:23:30 +0200 From: Mike Rapoport To: Breno Leitao Cc: Alexander Graf , Pasha Tatashin , Pratyush Yadav , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-mm@kvack.org, usamaarif642@gmail.com, rmikey@meta.com, clm@fb.com, riel@surriel.com, SeongJae Park , kernel-team@meta.com Subject: Re: [PATCH v5 1/4] kho: add size parameter to kho_add_subtree() Message-ID: References: <20260126-kho-v5-0-7cd0f69ab204@debian.org> <20260126-kho-v5-1-7cd0f69ab204@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260126-kho-v5-1-7cd0f69ab204@debian.org> X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: A2A92180007 X-Stat-Signature: hjeumq8shnr3kp131wkm1tgzkwmnk634 X-Rspam-User: X-HE-Tag: 1769498619-34548 X-HE-Meta: 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 oh3r72Hw uBe0kQXHY27sXTX0dLK+oIhDaq4+E9ZN+FwQqCdqNzS37XovOFHJP3yXCLlR5MepSKaird/YHj1SH1wkH0SZelb4JG4vsB7DAw9Jr3/mlwQKSwHF8AOaB2K+mIA+tl5xgXAM0UfVXDnUMIC5F0XEFzAUcuP5evH1lrfeT3J018hHGRsZsaxlotEE5+shwkvoQG7z6L7vofYL4I8/pRmVNbskPxRZQGLEc1JdrMTtxn9CJWZ0GAFyWbeAMq/OY7RSqmygYgNDO4/s8qkpad64v8yWSpI+Ml70tDtjqdxqH0wqukF1lA+2aGTLtoeHQCVteYOGP+plLQEGNWs0Y5NQwfrM8XVWgf9vvZ00a X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jan 26, 2026 at 08:07:23AM -0800, Breno Leitao wrote: > kho_add_subtree() assumes the fdt argument is always an FDT and calls > fdt_totalsize() on it in the debugfs code path. This assumption will > break if a caller passes arbitrary data instead of an FDT. > > When CONFIG_KEXEC_HANDOVER_DEBUGFS is enabled, kho_debugfs_fdt_add() > calls __kho_debugfs_fdt_add(), which executes: > > f->wrapper.size = fdt_totalsize(fdt); > > Fix this by adding an explicit size parameter to kho_add_subtree() so > callers specify the blob size. This allows subtrees to contain > arbitrary data formats, not just FDTs. Update all callers: > > - memblock.c: use fdt_totalsize(fdt) > - luo_core.c: use fdt_totalsize(fdt_out) > - test_kho.c: use fdt_totalsize() > - kexec_handover.c (root fdt): use fdt_totalsize(kho_out.fdt) > > Also update kho_in_debugfs_init() to compute sizes using fdt_totalsize() > for the root and sub-FDTs it processes, since these are known to be > actual FDT blobs. > > Suggested-by: Pratyush Yadav > Signed-off-by: Breno Leitao Reviewed-by: Mike Rapoport (Microsoft) > --- > include/linux/kexec_handover.h | 4 ++-- > kernel/liveupdate/kexec_handover.c | 8 +++++--- > kernel/liveupdate/kexec_handover_debugfs.c | 15 +++++++++------ > kernel/liveupdate/kexec_handover_internal.h | 5 +++-- > kernel/liveupdate/luo_core.c | 3 ++- > lib/test_kho.c | 3 ++- > mm/memblock.c | 2 +- > 7 files changed, 24 insertions(+), 16 deletions(-) > > diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h > index ac4129d1d7416..abb1d324f42d0 100644 > --- a/include/linux/kexec_handover.h > +++ b/include/linux/kexec_handover.h > @@ -32,7 +32,7 @@ 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); > +int kho_add_subtree(const char *name, void *fdt, size_t size); I'd rename 'void *fdt' to 'void *blob' to make it clearer that subtree isn't necessary an FDT. And s/fdt/blob/ in debugfs function names. All this could be a separate cleanup. -- Sincerely yours, Mike.