From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F9EF2C327E for ; Fri, 14 Nov 2025 21:35:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763156119; cv=none; b=R28Mgpd3sKBPUQEJpoZMJgsDophnkhrcF1a5edSYOIPM21FfDHpkUT+mxhRXfBLPPy+wN4KIwTd6hQPlOll1tmcFtNcOLzosU1zFQGCZMc31WHoho1Qm3iWwMKaDsZ91AS1GKDTaLfJ39D37BfqwrXCmSI7IB0qUXNKyNHCLsn0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763156119; c=relaxed/simple; bh=reZny+rVhXVu6iuyp84XnFfdpBkQZiuLc+BgXkfknHc=; h=Date:To:From:Subject:Message-Id; b=bmNg/FIk+wZhIYGy2/Lt24hQzhbFfsvZ2CzMM59nuX2DVdqjrbRambxpZxrpFJZv2ENdLnTLfKl3PQrZx7gBuAH5/CL3kGWc76rxOPIzIkXKak79HewQxZB2hc6UCln06Z69denQlWnHuSLALCJw0IWvi3miSyeFL+1XDvhGf38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Q7oaHp/a; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Q7oaHp/a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10AE9C2BC9E; Fri, 14 Nov 2025 21:35:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1763156119; bh=reZny+rVhXVu6iuyp84XnFfdpBkQZiuLc+BgXkfknHc=; h=Date:To:From:Subject:From; b=Q7oaHp/aCrjDBSNtG3VdvBerHPrMZNT8dp1xNw+OJoUnz/G13GgqPFgNea6l+n1jr W639Uh4VKl+ti16ke5do2FmWLZlO3M0d4qzcMhWKXks6/VSpYd12DpSGXQqHRUdiL1 pIpzXt9V4rZwrjsA1Jpmo6Lke9QmHu55cGP4oR5Q= Date: Fri, 14 Nov 2025 13:35:17 -0800 To: mm-commits@vger.kernel.org,rppt@kernel.org,pratyush@kernel.org,kees@kernel.org,graf@amazon.com,ebiggers@google.com,dave@vasilevsky.ca,coxu@redhat.com,bhe@redhat.com,arnd@arndb.de,pasha.tatashin@soleen.com,akpm@linux-foundation.org From: Andrew Morton Subject: + kho-verify-deserialization-status-and-fix-fdt-alignment-access.patch added to mm-nonmm-unstable branch Message-Id: <20251114213519.10AE9C2BC9E@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: kho: verify deserialization status and fix FDT alignment access has been added to the -mm mm-nonmm-unstable branch. Its filename is kho-verify-deserialization-status-and-fix-fdt-alignment-access.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kho-verify-deserialization-status-and-fix-fdt-alignment-access.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Pasha Tatashin Subject: kho: verify deserialization status and fix FDT alignment access Date: Fri, 14 Nov 2025 13:59:54 -0500 During boot, kho_restore_folio() relies on the memory map having been successfully deserialized. If deserialization fails or no map is present, attempting to restore the FDT folio is unsafe. Update kho_mem_deserialize() to return a boolean indicating success. Use this return value in kho_memory_init() to disable KHO if deserialization fails. Also, the incoming FDT folio is never used, there is no reason to restore it. Additionally, use get_unaligned() to retrieve the memory map pointer from the FDT. FDT properties are not guaranteed to be naturally aligned, and accessing a 64-bit value via a pointer that is only 32-bit aligned can cause faults. Link: https://lkml.kernel.org/r/20251114190002.3311679-6-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Pratyush Yadav Cc: Alexander Graf Cc: Arnd Bergmann Cc: Baoquan He Cc: Coiby Xu Cc: Dave Vasilevsky Cc: Eric Biggers Cc: Kees Cook Signed-off-by: Andrew Morton --- kernel/liveupdate/kexec_handover.c | 32 ++++++++++++++++----------- 1 file changed, 19 insertions(+), 13 deletions(-) --- a/kernel/liveupdate/kexec_handover.c~kho-verify-deserialization-status-and-fix-fdt-alignment-access +++ a/kernel/liveupdate/kexec_handover.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -451,20 +452,27 @@ static void __init deserialize_bitmap(un } } -static void __init kho_mem_deserialize(const void *fdt) +/* Return true if memory was deserizlied */ +static bool __init kho_mem_deserialize(const void *fdt) { struct khoser_mem_chunk *chunk; - const phys_addr_t *mem; + const void *mem_ptr; + u64 mem; int len; - mem = fdt_getprop(fdt, 0, PROP_PRESERVED_MEMORY_MAP, &len); - - if (!mem || len != sizeof(*mem)) { + mem_ptr = fdt_getprop(fdt, 0, PROP_PRESERVED_MEMORY_MAP, &len); + if (!mem_ptr || len != sizeof(u64)) { pr_err("failed to get preserved memory bitmaps\n"); - return; + return false; } - chunk = *mem ? phys_to_virt(*mem) : NULL; + mem = get_unaligned((const u64 *)mem_ptr); + chunk = mem ? phys_to_virt(mem) : NULL; + + /* No preserved physical pages were passed, no deserialization */ + if (!chunk) + return false; + while (chunk) { unsigned int i; @@ -473,6 +481,8 @@ static void __init kho_mem_deserialize(c &chunk->bitmaps[i]); chunk = KHOSER_LOAD_PTR(chunk->hdr.next); } + + return true; } /* @@ -1458,16 +1468,12 @@ static void __init kho_release_scratch(v void __init kho_memory_init(void) { - struct folio *folio; - if (kho_in.scratch_phys) { kho_scratch = phys_to_virt(kho_in.scratch_phys); kho_release_scratch(); - kho_mem_deserialize(kho_get_fdt()); - folio = kho_restore_folio(kho_in.fdt_phys); - if (!folio) - pr_warn("failed to restore folio for KHO fdt\n"); + if (!kho_mem_deserialize(kho_get_fdt())) + kho_in.fdt_phys = 0; } else { kho_reserve_scratch(); } _ Patches currently in -mm which might be from pasha.tatashin@soleen.com are lib-test_kho-check-if-kho-is-enabled.patch kho-make-debugfs-interface-optional.patch kho-add-interfaces-to-unpreserve-folios-page-ranges-and-vmalloc.patch memblock-unpreserve-memory-in-case-of-error.patch test_kho-unpreserve-memory-in-case-of-error.patch kho-dont-unpreserve-memory-during-abort.patch liveupdate-kho-move-to-kernel-liveupdate.patch liveupdate-kho-move-to-kernel-liveupdate-fix.patch maintainers-update-kho-maintainers.patch kho-fix-misleading-log-message-in-kho_populate.patch kho-convert-__kho_abort-to-return-void.patch kho-introduce-high-level-memory-allocation-api.patch kho-preserve-fdt-folio-only-once-during-initialization.patch kho-verify-deserialization-status-and-fix-fdt-alignment-access.patch kho-always-expose-output-fdt-in-debugfs.patch kho-simplify-serialization-and-remove-__kho_abort.patch kho-remove-global-preserved_mem_map-and-store-state-in-fdt.patch kho-remove-abort-functionality-and-support-state-refresh.patch kho-update-fdt-dynamically-for-subtree-addition-removal.patch kho-allow-kexec-load-before-kho-finalization.patch kho-allow-memory-preservation-state-updates-after-finalization.patch kho-add-kconfig-option-to-enable-kho-by-default.patch liveupdate-luo_core-luo_ioctl-live-update-orchestrator.patch liveupdate-luo_core-integrate-with-kho.patch reboot-call-liveupdate_reboot-before-kexec.patch liveupdate-luo_session-add-sessions-support.patch liveupdate-luo_ioctl-add-user-interface.patch liveupdate-luo_file-implement-file-systems-callbacks.patch liveupdate-luo_session-add-ioctls-for-file-preservation-and-state-management.patch liveupdate-luo_flb-introduce-file-lifecycle-bound-global-state.patch docs-add-luo-documentation.patch maintainers-add-liveupdate-entry.patch selftests-liveupdate-add-userspace-api-selftests.patch selftests-liveupdate-add-kexec-based-selftest-for-session-lifecycle.patch selftests-liveupdate-add-kexec-test-for-multiple-and-empty-sessions.patch tests-liveupdate-add-in-kernel-liveupdate-test.patch