From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.198 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793140751; b=qAaaF/gu+2xtmhW2P8eejd1IRQ3t+HAP9GiNwdDk40+ip3pi6ef23fyTzZLM4F2q8dL6 PoMix0Cmk+q0Clo7mXG51ybXZeuhXJUN85lAL6aL9m7ratMQIeBDDiaOP8jJc4YDFudhw vw+O8F6A5MghWeI92BnA2Cps3r/llfSLyidPNyZP/cJ76bNbOLhCFz7a5F9vYJCjT17F/ 20lMQG/skYAPqzRAmPnPxFXaCUdkgkvaKMoM/axrrsL6yGYzlhvo4Xsr6vVPjh8YOk/mC 19n6efXxT/2yO8TA7DKQwqPxEhleIf3/TJvwiZdJovuVWZjk7WviJ49cOW5pHYFORSw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793140751; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Received:Date:Mime-Version: X-Mailer:Message-ID:Subject:From:To:Cc:Content-Type; bh=pEmx5PL3tlnBiGr2rjVOl0G+YHkBW7VB5cziBEiH9l0=; b=NGMO1M672fd8UcP0fdhZxzLTmXsmLwA3Q59Ful98XVe9T3aSZA8xrLdnYl7Oy9YV0j2S UC7wrpodE75KuAYlADSwIp+29VFT4HYPGh/Ei8u6r21pOFDXrK8d19gWPemJPeSoC8PDx RVux1h0xR/2v9o9R+8R6pIDBc7mbrregu71FoygE9MGkp3Kganl7eFPm3SnZMiSAysb+7 zBtFToy8xmoe1vT3MGJNfFIdgkHmb9gBqfNlePJ7novt53uEFP3HUIGZBY9zY9rJtuUqg 0V4QKiNdqsHjXeN0RTikzDa2mxlvxaZ8/Kmvem4pohDX8bbuIa1P3/+y7wT+1uRL1/w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=WwyADfSB; arc=none smtp.remote-ip=74.125.82.198 Received: from mail-dy1-f198.google.com (mail-dy1-f198.google.com [74.125.82.198]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 40926606A320 for ; Tue, 27 Oct 2026 22:39:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 40926606A320 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=WwyADfSB Received: by mail-dy1-f198.google.com with SMTP id 5a478bee46e88-33c35f5ca6cso579221eec.1 for ; Tue, 27 Oct 2026 15:39:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20260707; t=1793140749; x=1793745549; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=pEmx5PL3tlnBiGr2rjVOl0G+YHkBW7VB5cziBEiH9l0=; b=WwyADfSBKnfQhnWY2Vcc6CNZLTbO+rAle5B1hKwX8je30uuwYFtB/vLJcoE5YY8g3l ZP1V0bwQMghUb9OH8d+nqaUwuF0QhBserXEYkJY30hDkrjNFMmDQV+NHMsvOfzeO5Smj W3fOXMl0JNgZhE7FX+6rfE0FyfvCs0KmuVF9AJhs4u5xFwJMb+jaWfil9w878EOrRsZY CUqereYX0RsTxyE2KJ/ls1UGDevHByw15KWdqkK8Ms8Ozs9o6RT8cmJwBsNQm2eQleg+ e1ohgzf4BQQIJO/4X/jZBsZEqtoprO5FOBgNNOSI0iyC+HNFg11Ynpnkv5fSF/W9aYty crcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793140749; x=1793745549; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=pEmx5PL3tlnBiGr2rjVOl0G+YHkBW7VB5cziBEiH9l0=; b=Nn04RuRl55/88xtL2x7bDVZo9FOJHrWdE2qhAfnBsHGif/Gt9frVMDsA3sXiRREFx+ W4WwBFw873FTSPrGTQsaLc2iMKVQsM2AM76uNQOd3do6C7HCi21db2iYn8oOQgKghVWM geBHsUGjAvzaVNQBPPocBQEj2SE0sA0+dHX4bulvyOXITNXhC57Xl3vO0mlMJqJwGFo9 3417qpAigZPjVfVdkwcdm1jMIvFzlaGJINGVJhuWNeZsvKUv2ENPNMYcdaATJThAsNdV x+qsBA2KmTXUpUy5ZUe7CgdijM62E6PQse7IZ7XvoMYyzzKty/f6pH9hTMmpmvAHBpk8 3e/g== X-Forwarded-Encrypted: i=1; AKwUvBzVLvrryhVcLhP5dyAi619sEzSq/G/YX0IzTnzAeqGXL3POPd05/gjU/3HLYYBLUdTrh1P+/43B7g==@vger.kernel.org X-Gm-Message-State: AFq9FYI4b4+O/+Z7HCjX+XQ2V1Tswawbmh4IMqtRWtGCgaSam/PfduME bpaGFdjGNmrH5HJNoeF+chX8ohFKvEm+3xnGRA5fLg++1XYuTRbr3/PGm+lK8kC+Q+CHkL1el0+ yT4YwrfS5bQ== X-Received: from dli9.prod.google.com ([2002:a05:7022:289:b0:1a1:da78:f9b9]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:6989:b0:165:90af:a25f with SMTP id a92af1059eb24-1a6cfa0c447mr941563c88.41.1793140748444; Tue, 27 Oct 2026 15:39:08 -0700 (PDT) Date: Tue, 27 Oct 2026 15:38:35 -0700 X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 X-Mailer: git-send-email 2.56.0.313.g2479322e68-goog Message-ID: <20261027223847.652884-1-irogers@google.com> Subject: [PATCH v2 0/9] Add __must_init and require explicit kobj_type::release From: Ian Rogers To: Kees Cook , Greg Kroah-Hartman , Miguel Ojeda , "Rafael J . Wysocki" , Danilo Krummrich Cc: Nathan Chancellor , Nick Desaulniers , Miguel Ojeda , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , Zhihao Cheng , Zhongqiu Han , Sumanth Korikkar , Bill Wendling , Justin Stitt , driver-core@lists.linux.dev, llvm@lists.linux.dev, linux-hardening@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, linux-s390@vger.kernel.org, gfs2@lists.linux.dev, xen-devel@lists.xenproject.org, linux-mtd@lists.infradead.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Ian Rogers Content-Type: text/plain; charset="UTF-8" Clang supports the 'require_explicit_initialization' attribute on struct fields to enforce that the field is explicitly initialized when an aggregate object is constructed, emitting -Wuninitialized-explicit-init (enabled by default) if the field is omitted. Following discussion at the Linux Plumbers Conference [1], patch 1 adds the attribute to include/linux/compiler_attributes.h as __must_init. In v1 it was called __require_explicit_initialization. Kees picked up that patch with a first seq_file user [2], and in that thread Greg suggested the shorter __must_init spelling, which Kees and Miguel agreed to. As the attribute did not land in the v7.4 merge window, Kees asked that this series carry the renamed attribute. The Acked-by/Reviewed-by tags on patch 1 were given for the original spelling; the rename is mechanical. As Documentation/core-api/kobject.rst notes: "One important point cannot be overstated: every kobject must have a release() method, and the kobject must persist (in a consistent state) until that method is called. If these constraints are not met, the code is flawed." Annotating struct kobj_type::release caught struct kobj_type definitions across the tree that omitted .release: - Patches 2-8 fix struct kobj_type definitions where dynamically allocated kobjects, ksets, or enclosing structures were either leaked on kobject_put(), freed prematurely before kobject release, or missing proper static initializers. - Patch 9 annotates struct kobj_type::release with __must_init and explicitly sets .release = NULL (with explanatory comments prefixed with "Pre-existing:") on the remaining legacy struct kobj_type definitions whose kobjects are static, per-CPU, permanent firmware structures, or embedded in devm- or parent-managed structures. Note on tool use: An LLM coding assistant was used to help audit the compiler diagnostics across the tree, draft the fixes and changelog descriptions, and verify builds and review feedback. Changes in v2: - Rebased on v7.3-16928-g83f32c773255 (v7.4 merge window). - Patch 1: Rename __require_explicit_initialization to __must_init per Greg Kroah-Hartman; document the Clang >= 20 requirement per Miguel Ojeda; note the Clang gap for file-scope objects without an initializer reported by Kees Cook; add tags from v1 and from Kees's posting. - Move LLM assistance attribution from Assisted-by tags to this cover letter per commit 1e035297ffda ("docs: remove Assisted-by references"). - Patch 4 (cpufreq): Use "cpufreq: governor:" prefix, drop Fixes tag, fix typo, and remove the redundant runtime assignment in cpufreq_dbs_governor_init() per Zhongqiu Han. - Dropped v1 patch 5 (ACPI: CPPC), already fixed upstream by commit 27954e29d7de ("ACPI: CPPC: Release CPC descriptors through kobject"). - Patch 5 (dlm): Call kobject_del() before dlm_recoverd_stop() in release_lockspace() and the new_lockspace() error path, and wait on a new ls_kobj_done completion before freeing the lockspace or dropping the module reference, avoiding races with delayed kobject release. - Dropped v1 patch 8 (s390/sclp_mem) per Sumanth Korikkar: the /sys/firmware/memory/memoryX kobjects are permanent, so sclp_mem.c is folded into patch 9 with .release = NULL. - Patch 7 (ubifs): Add Tested-by and Reviewed-by from Zhihao Cheng. - Patch 8 (drm/amdkfd): Check q->kobj.state_in_sysfs before kobject_del() in kfd_procfs_del_queue(). - Patch 9 (kobject): Cover sclp_mem.c and the new amdgpu_ualink.c ualink_xcp_info_ktype, fix the overlay-sysfs.c comment, and prefix legacy .release = NULL comments with "Pre-existing:". - Patch 9 (kobject): The ioat, kunpeng_hccs and omapfb display comments now say that the existing teardown can use-after-free under CONFIG_DEBUG_KOBJECT_RELEASE (reported by Sashiko). Fixing those drivers is left to follow-up patches. v1: https://lore.kernel.org/all/20261013223946.1836757-1-irogers@google.com/ [1] https://lpc.events/event/20/contributions/2392/ [2] https://lore.kernel.org/lkml/20261014225811.i.852-kees@kernel.org/ Ian Rogers (9): Compiler Attributes: Add __must_init macro powerpc/secvar: Add missing kobject release callback to secvar_ktype sh: sq: Add missing kobject release callback to ktype_percpu_entry cpufreq: governor: Initialize kobj_type release callback statically dlm: Free dlm_ls in kobject release callback xen/sys-hypervisor: Add release callback to hyp_sysfs_kobj_type ubifs: sysfs: Use kset_create_and_add() for ubifs_kset drm/amdkfd: Free queue in procfs_queue_type kobject release callback kobject: Require explicit initialization of struct kobj_type::release Documentation/conf.py | 1 + arch/arm64/kernel/cpuinfo.c | 5 ++++ arch/powerpc/kernel/secvar-sysfs.c | 6 +++++ arch/sh/kernel/cpu/sh4/sq.c | 6 +++++ drivers/acpi/sysfs.c | 2 ++ drivers/cpufreq/cpufreq_conservative.c | 5 +++- drivers/cpufreq/cpufreq_governor.c | 4 +-- drivers/cpufreq/cpufreq_governor.h | 1 + drivers/cpufreq/cpufreq_ondemand.c | 5 +++- drivers/dma/ioat/sysfs.c | 7 +++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c | 5 ++++ drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c | 10 +++++++ drivers/gpu/drm/amd/amdkfd/kfd_process.c | 12 ++++++--- drivers/gpu/drm/amd/amdkfd/kfd_queue.c | 5 +++- drivers/infiniband/hw/hfi1/sysfs.c | 5 ++++ drivers/infiniband/hw/usnic/usnic_ib_sysfs.c | 2 ++ drivers/parisc/pdc_stable.c | 5 ++++ drivers/power/supply/ab8500_fg.c | 5 ++++ drivers/s390/char/sclp_mem.c | 2 ++ drivers/soc/hisilicon/kunpeng_hccs.c | 21 +++++++++++++++ .../fbdev/omap2/omapfb/dss/display-sysfs.c | 7 +++++ .../fbdev/omap2/omapfb/dss/manager-sysfs.c | 5 ++++ .../fbdev/omap2/omapfb/dss/overlay-sysfs.c | 5 ++++ drivers/xen/sys-hypervisor.c | 6 +++++ fs/dlm/dlm_internal.h | 1 + fs/dlm/lockspace.c | 26 ++++++++++++++----- fs/erofs/sysfs.c | 10 +++++++ fs/f2fs/sysfs.c | 15 +++++++++++ fs/ocfs2/cluster/masklog.c | 5 ++++ fs/ubifs/sysfs.c | 24 +++++------------ include/linux/compiler_attributes.h | 12 +++++++++ include/linux/kobject.h | 2 +- scripts/checkpatch.pl | 1 + tools/lib/python/kdoc/xforms_lists.py | 1 + 34 files changed, 202 insertions(+), 32 deletions(-) base-commit: 83f32c773255720a661aa45d83e36278135f23f5 -- 2.56.0.313.g2479322e68-goog