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 97AB9CD4F4A for ; Sun, 17 May 2026 18:36:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B1ABD6B0005; Sun, 17 May 2026 14:36:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ACBA16B0088; Sun, 17 May 2026 14:36:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9BB106B008C; Sun, 17 May 2026 14:36:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 855F96B0005 for ; Sun, 17 May 2026 14:36:42 -0400 (EDT) Received: from smtpin15.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 4557340677 for ; Sun, 17 May 2026 18:36:41 +0000 (UTC) X-FDA: 84777767802.15.9DA96D3 Received: from mail-qk1-f170.google.com (mail-qk1-f170.google.com [209.85.222.170]) by imf08.hostedemail.com (Postfix) with ESMTP id 62F82160006 for ; Sun, 17 May 2026 18:36:39 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=soleen.com header.s=google header.b=LXuwhsww; dmarc=pass (policy=reject) header.from=soleen.com; spf=pass (imf08.hostedemail.com: domain of pasha.tatashin@soleen.com designates 209.85.222.170 as permitted sender) smtp.mailfrom=pasha.tatashin@soleen.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1779042999; 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=lirFWsJ5C0bTd/R7aKsYhvTxoj04iUNEXEllFWQcIOE=; b=nXvkuH3gUuTngAk97d72x17ecq1dRm7YMkB33YGNomBF1EGxulsCcSmUzyV4k28UpwxQnn 63tGBa1oB5P/vuHHgKSj9X3/zTFYXa2YPYnVhY+WvVMDCM31ULJfBv+5RhKHHUENhvuHiF uBaCuqqwFuax9ZufplmPkaijdIvz6LI= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1779042999; a=rsa-sha256; cv=none; b=0iejZroA6SeseNvuerwRbBhUqFZLhQxmwGiFTkZtSLAKr68QYkLfoS6YS+HNAQ36SCAyN9 gnItNYxsgfkYuNOETWkkiqUy/MDnn+8kzkiyqsEgbPQIn4HTumhgET5j5tSgSKCHp3adlT mWoxEShhTNMEFUAfE0lnNs9KiecPKe8= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=soleen.com header.s=google header.b=LXuwhsww; dmarc=pass (policy=reject) header.from=soleen.com; spf=pass (imf08.hostedemail.com: domain of pasha.tatashin@soleen.com designates 209.85.222.170 as permitted sender) smtp.mailfrom=pasha.tatashin@soleen.com Received: by mail-qk1-f170.google.com with SMTP id af79cd13be357-91080895355so200445685a.3 for ; Sun, 17 May 2026 11:36:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; t=1779042998; x=1779647798; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=lirFWsJ5C0bTd/R7aKsYhvTxoj04iUNEXEllFWQcIOE=; b=LXuwhswwMPbkFq8/eaj1pNOEXKb6QwUr8zU+nLDj1c/avHvZZ/cA83xaKj+DRHNLVq NYQ5khpSTVnMiZPN5NLwmda45WQKYHx88/vrRhtgal0hL1hNmHGXpcEbugVv97sXMASO AnvZw/ppJIFpA0xjViB6t9v92fR/a0IJ79ENp2lDoep13Xh8luSUMe5OOt4usV1Fgqmi 2tGpgArDNNRiu8Ysq705gP7+RRgUk1jExwesVnNH/67CdfrRt0SqMwJt86MM1shrvPfm PZSxV4bwslKVU2fzJxcqY9qGcZRbt7b4uIsHXUq84HCZ0CYGob18H29u/znPkXQtdJf2 oyaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779042998; x=1779647798; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=lirFWsJ5C0bTd/R7aKsYhvTxoj04iUNEXEllFWQcIOE=; b=gNOhGAZiqEPx9o0qsjJHM8WSyDg6kNgicCmAmATAUloSOUa2Bc7mL1ENWHju7lMzVC 0S9oodEDAzkwsRn/sTnJWrVXck/xQXVXJ22BtBTW7oUnIYUkj03KLwy0QyayBN51JFn0 lT4o/rFS9kBuAcP2ZLpNmGEaEVnvsL11NKHv3ruDTqbGMpRYvpj4uJ7wW5sGRX2zaYtu MPH9R1i+PzTk+yNWIFAWh48MaPMsSUsHH9g6a87Kna68pq8poi3NOztfWQ0yoefMfb9N Qz3AFayAWhn/guH+kBK54t/J/GNxdk1E53yh6NfytGGTC1h3DCpmX+mrzRj6DfikK6vr shdg== X-Forwarded-Encrypted: i=1; AFNElJ8qLbX8TWhpbI81BVc3KkWpu3gkKtPUpyKvAVQf7nY5kfgTwFmoj7RX77mYdsscUVF78i0YmiqxrA==@kvack.org X-Gm-Message-State: AOJu0Yyg1PB95ujq3SwMLczL0MwOs/fg93uE3QD5EPLgtTVrdVnfmgJF n5iCfX0YY813QM5Ctx5a3088rnfKdTKMi+4CnBC9WzEe98CzNfhAwgEIuaYyOf2OKHE= X-Gm-Gg: Acq92OGccagnAL4VrvECQXyc4U+QaJ5EJht6h5jrd1JkwmPvWM+eDUbFk+kNNmEaGBp QtHYDRxby7/zcbZ6KQVYMWQSXD6R4SG617uffK8LuqXs5t7iL6nv3KocuBH953/5GqMyvyTkswy b5igKSNnuLioSIliuNZusPrhBoJwCCut7/gtwyV47rbpB8v1/CaItqpdek+/26PUm/m+okLWSAC +AO1sBHU0CBvGATk7zu6yTnYsvFoVrGxPbp8FLxWK9MkNr3M0VHBURtWMi3+ESiHbr6p3Ui+lNJ tqk50cDYbH8u+SlN27XD7bnPF/g7diYDXfhtDljn2hdWbkYkb0Fa13moSSzf+/THv+34bn/D6Aw rKEdEcEkTALqdXHPDp49ac4UZyx6Of7Ifp8bS0Yj48iuV/8syNPQXPLnYyojHtxbpZsqW8N5jt7 ljTR2BTw4rmhgSs1WJO55d4Sm9qK+4FBEKVfCrZ8pWU+YD3dTnOJ8= X-Received: by 2002:a05:620a:6cc6:b0:911:a9e4:8b04 with SMTP id af79cd13be357-911d1042fc0mr1877269085a.62.1779042998343; Sun, 17 May 2026 11:36:38 -0700 (PDT) Received: from plex ([71.181.43.54]) by smtp.gmail.com with ESMTPSA id af79cd13be357-910bcf3584esm1221812385a.34.2026.05.17.11.36.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 17 May 2026 11:36:37 -0700 (PDT) Date: Sun, 17 May 2026 18:36:36 +0000 From: Pasha Tatashin To: Mike Rapoport Cc: Pasha Tatashin , linux-kselftest@vger.kernel.org, shuah@kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, skhan@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, corbet@lwn.net, dmatlack@google.com, kexec@lists.infradead.org, pratyush@kernel.org, skhawaja@google.com, graf@amazon.com Subject: Re: [PATCH v2 01/10] liveupdate: centralize state management into struct luo_ser Message-ID: References: <20260514222628.931312-1-pasha.tatashin@soleen.com> <20260514222628.931312-2-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Queue-Id: 62F82160006 X-Rspamd-Server: rspam04 X-Stat-Signature: pn94ggqfmsy1xyrngu465bwdaxifmgqn X-HE-Tag: 1779042999-50739 X-HE-Meta: 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 1eaXYJLP dlvOd/QXfggNrswTubus4n3KXy1ciOVG5B085CITGt7GPC7+bsAAkaO12xdKydjPwHhVjI6Euxt+ia/HtQD7jdiHKnlJnyMXU3twWTJ4xhPHxokSJv4A5L5iy49YEXHsgq+/3P0TNNXK4+EdVzEo9RoTxa1Q5Lb51eJmc6ikUOxjNqujEBeoWJDqX9gwoYnChnnCD6Ox20Iv6v89DmWZe3lnbqzs0fst21NrlYPmUqYzzmyTWXJV5cGcHV597LsUecfNOl71NpdLZBPDj/2AnfSOGOccFP8Q9G2jYQQjNSNov7Q6563mmyZzBIlEu53IGenZhA0k7w9x4bxw9tciLrOVEVmtiZT94JHSjAYg+lW34nRgAUJHrXsvRz2rn4D6HoHLcxQU8GNt68pYf+AZwT/LuyMHmuhKPGppfCoTbHsNIB8PSXe0eN8Hqp+CFlMTO5axzx0QEveQFEDTziNHtvukbcw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 05-17 20:20, Mike Rapoport wrote: > On Thu, May 14, 2026 at 10:26:19PM +0000, Pasha Tatashin wrote: > > Transition the LUO to ABI v2, which centralizes state management into a > > single struct luo_ser header. > > > > Previously, LUO state was spread across multiple FDT properties and > > subnodes. ABI v2 simplifies this by placing all core state, including > > the liveupdate number and physical addresses for sessions and FLB > > headers into a centralized struct luo_ser. > > > > Signed-off-by: Pasha Tatashin > > --- > > include/linux/kho/abi/luo.h | 91 +++++++++++--------------------- > > kernel/liveupdate/luo_core.c | 59 ++++++++++++++------- > > kernel/liveupdate/luo_flb.c | 65 ++++------------------- > > kernel/liveupdate/luo_internal.h | 8 +-- > > kernel/liveupdate/luo_session.c | 57 +++----------------- > > 5 files changed, 93 insertions(+), 187 deletions(-) > > This looks lovely :) > > > @@ -115,27 +117,29 @@ static int __init luo_early_startup(void) > > return -EINVAL; > > } > > > > - ln_size = 0; > > - ptr = fdt_getprop(luo_global.fdt_in, 0, LUO_FDT_LIVEUPDATE_NUM, > > - &ln_size); > > - if (!ptr || ln_size != sizeof(luo_global.liveupdate_num)) { > > - pr_err("Unable to get live update number '%s' [%d]\n", > > - LUO_FDT_LIVEUPDATE_NUM, ln_size); > > + header_size = 0; > > + ptr = fdt_getprop(luo_global.fdt_in, 0, LUO_FDT_ABI_HEADER, &header_size); > > + if (!ptr || header_size != sizeof(u64)) { > > + pr_err("Unable to get ABI header '%s' [%d]\n", > > + LUO_FDT_ABI_HEADER, header_size); > > > > return -EINVAL; > > } > > > > - luo_global.liveupdate_num = get_unaligned((u64 *)ptr); > > + luo_ser_pa = get_unaligned((u64 *)ptr); > > + luo_ser = phys_to_virt(luo_ser_pa); > > + > > + luo_global.liveupdate_num = luo_ser->liveupdate_num; > > pr_info("Retrieved live update data, liveupdate number: %lld\n", > > luo_global.liveupdate_num); > > > > - err = luo_session_setup_incoming(luo_global.fdt_in); > > + err = luo_session_setup_incoming(luo_ser->sessions_pa); > > if (err) > > return err; > > > > - err = luo_flb_setup_incoming(luo_global.fdt_in); > > + luo_flb_setup_incoming(luo_ser->flbs_pa); > > Sashiko asks: > > Is there a leak of the preserved luo_ser memory here? > > The outgoing kernel allocates the header using kho_alloc_preserve(), but > luo_early_startup() returns without calling kho_restore_free() on the > luo_ser pointer once the fields have been processed. This results in an > unreleased memory reservation on every successful live update. > > This seems preexisting, and we probably don't care enough, but still... The freeing happen during finish, that was by design. > > There were more comments by sashiko, didn't check them yet. The other comment is stupid: yes, changing ABI prevents updating from older kernel. > > > - return err; > > + return 0; > > } > > > > static int __init liveupdate_early_init(void) > > @@ -156,7 +160,8 @@ early_initcall(liveupdate_early_init); > > /* Called during boot to create outgoing LUO fdt tree */ > > static int __init luo_fdt_setup(void) > > { > > - const u64 ln = luo_global.liveupdate_num + 1; > > + struct luo_ser *luo_ser; > > + u64 luo_ser_pa; > > void *fdt_out; > > int err; > > > > @@ -166,27 +171,45 @@ static int __init luo_fdt_setup(void) > > return PTR_ERR(fdt_out); > > } > > > > + luo_ser = kho_alloc_preserve(sizeof(*luo_ser)); > > + if (IS_ERR(luo_ser)) { > > + err = PTR_ERR(luo_ser); > > + goto exit_free_fdt; > > + } > > + luo_ser_pa = virt_to_phys(luo_ser); > > + > > err = fdt_create(fdt_out, LUO_FDT_SIZE); > > err |= fdt_finish_reservemap(fdt_out); > > err |= fdt_begin_node(fdt_out, ""); > > err |= fdt_property_string(fdt_out, "compatible", LUO_FDT_COMPATIBLE); > > - err |= fdt_property(fdt_out, LUO_FDT_LIVEUPDATE_NUM, &ln, sizeof(ln)); > > - err |= luo_session_setup_outgoing(fdt_out); > > - err |= luo_flb_setup_outgoing(fdt_out); > > + err |= fdt_property(fdt_out, LUO_FDT_ABI_HEADER, &luo_ser_pa, > > + sizeof(luo_ser_pa)); > > err |= fdt_end_node(fdt_out); > > err |= fdt_finish(fdt_out); > > if (err) > > - goto exit_free; > > + goto exit_free_luo_ser; > > + > > + err = luo_session_setup_outgoing(&luo_ser->sessions_pa); > > + if (err) > > + goto exit_free_luo_ser; > > + > > + err = luo_flb_setup_outgoing(&luo_ser->flbs_pa); > > + if (err) > > + goto exit_free_luo_ser; > > + > > + luo_ser->liveupdate_num = luo_global.liveupdate_num + 1; > > > > err = kho_add_subtree(LUO_FDT_KHO_ENTRY_NAME, fdt_out, > > fdt_totalsize(fdt_out)); > > if (err) > > - goto exit_free; > > + goto exit_free_luo_ser; > > And here we also seem to leak memory allocated by sesttion/flb setup. > > > luo_global.fdt_out = fdt_out; > > > > return 0; > > > > -exit_free: > > +exit_free_luo_ser: > > + kho_unpreserve_free(luo_ser); > > +exit_free_fdt: > > kho_unpreserve_free(fdt_out); > > pr_err("failed to prepare LUO FDT: %d\n", err); > > -- > Sincerely yours, > Mike.