From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793848450; b=AfO4pMNUae3oIVRG37aqdOZOvtKxtQrimRJUkj3pjhUfllKAirRVGSARyI/e/NlMw3zs FYVpf9iux1Tl2lWJ+VoGNBEFN8xjuimZXJFBCAF6K0WeaX2uW5lHNrPQFOEeNfEDxNRXH hzE1sZCHXxiXuLLBB2J972x0L3OCLg/hkRIhfLqTLbEAv8PA8NqWDCA3RyIQlF6eSgVW5 U+dQO7q8/pWm3ql1sWpzRbFiHxZFO+h8GoCwBoz6g4s49XJQSm0489o48ppWT6ZZ75cVm zK5BcrGh9GT987EnAubA4R+9VWPXfpDkz/q9uvEujlmJu0ox7Z9pRRMrPet+42xLg3Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793848450; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Transfer-Encoding; bh=L0N4h6zVhz8n4j2GJtb5w0EICipqh7ENfZG1U4Wef4U=; b=GUIk+NsxyXYUm9+SOv01iOC3shu8KTEmtxSHunS2fzQ9cMwhXu5OF5wpV44hDMwJPV5K rwTcSDYvlelnH0qB/uOpnPnXqnEhaebdbEAkBca+gdskFtPUZsTP2LGAh54wvHoNNs34S DgBELPzKXLIgPyYVfKsu8FwpbD4WmY5LBmxn6ZugUAgTex44VaGolRNHBpCfZprY4RENb BD8nVy7+90C/Z0UszvnPQhxw1hilk0PugU2rp61EsTuFtBRLFtfE1YJLkiN/V3rKIws8i RCqMvHxdGLbsf7CDrUqhDeEob6vHh+TkGqvpZJOKEdawNfV3x3bODKIS9JHOAclNCyg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jGmC66uV; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 4D548606A326; Thu, 5 Nov 2026 03:14:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jGmC66uV Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 6A3771F000C1; Thu, 5 Nov 2026 03:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793848450; bh=L0N4h6zVhz8n4j2GJtb5w0EICipqh7ENfZG1U4Wef4U=; h=From:To:Cc:Subject:Date; b=jGmC66uVgeCFbUHtFNO+hOg7MvGttGjB44HcZJG1rIT6uKwQfi1MZ2Lvr6F8aBY4e A0cjaJ/aAALAR7+ZFjmJWaml6VRQ9nVFe1wlRz2BGJLY8S1y8G6d2S8Og/PwqvDoSp c3oK6/vxt1PDDOIwP3qlFWmsYf9lu3GNyrHrv5N/F77eBFP1a7pUn3mOB6xPOnUokQ pJG5jkSHowFEYfgVlfrWpwh2c5oE65zdr+uzjaLW2WGPPnUjkz3a5uHl7ld9/oKaG8 4tEBGahu5k1NChvzYP6Fwc3/8Axpv7tkWBhUOKfHb33dJgE0EiuTD2n7Fd6TBiPDnG FYIcNuJtr/VhQ== From: Jarkko Sakkinen To: David Howells Cc: Jarkko Sakkinen , bpf@vger.kernel.org, dm-devel@lists.linux.dev, fsverity@lists.linux.dev, keyrings@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-security-module@vger.kernel.org, Alasdair Kergon , Alexei Starovoitov , Alex Shi , Andrew Morton , Andrii Nakryiko , Benjamin Marzinski , Daniel Borkmann , Dongliang Mu , Eduard Zingerman , Emil Tsalapatis , Eric Biggers , Ihor Solodrai , James Morris , Jiri Olsa , Jonathan Corbet , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Mike Snitzer , Mikulas Patocka , Paul Moore , Randy Dunlap , "Serge E. Hallyn" , Shuah Khan , Song Liu , "Theodore Y. Ts'o" , Yanteng Si , Yonghong Song Subject: [PATCH v5 0/3] KEYS: Replace assoc_array with rhashtable Date: Thu, 5 Nov 2026 05:13:58 +0200 Message-ID: <20261105031401.956609-1-jarkko@kernel.org> X-Mailer: git-send-email 2.47.3 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The keyrings subsystem is the sole user of assoc_array. It has over 1700 lines of code, no test suite, and a long history of bugs, with LLMs now finding more. This unfortunate outcome has evolved over time by large from the shortage of in-kernel callers, time bandwidth and 3rd party contributors. What the keyrings subsystem needs is just a generic key-value store, which performs well with sparse key sets. Replace assoc_array with an rhashtable-backed keyring index and remove assoc_array from the kernel. CHANGES ======= v5: - Eric Biggers: Include explicitly in keyring.c. - Eric Biggers: Document why hashing type/domain_tag pointers with SipHash and truncating the digest to 32 bits are safe. - Eric Biggers: Rework the commit message for "KEYS: Replace assoc_array with rhashtable", including behavioral and operational changes. - Retry rhashtable_insert_fast() on transient -EBUSY in __key_link_begin(). v4: - Eric Biggers: Correct the kerneldoc summary for keyring_is_empty(). - Eric Biggers: Truncate keyring_index_key hash to u32 and drop index_id. - Eric Biggers, David Howells: Use a proper struct instead of a two-element array to pass the edits. - Eric Biggers: __keyring_link(): Call key_put() in the rollback of rhashtable_replace_fast(). - Eric Biggers: Retract from using __free(kfree) in keyring_get_index(). - Eric Biggers: Reuse keyring_link_key() in keyring_obj_cmpfn(). - Eric Biggers: Document why keyring_index_free() uses queue_rcu_work(). - Eric Biggers: Fix the commit message for "KEYS: Replace assoc_array with rhashtable". v3: - Since David is away for the next week I decided to address the low hanging fruit that I reported myself. - Unified and sanitized function and variable naming and removed unnecessary asymmetry e.g., by renaming keyring_remove_all_links as keyring_index_free, 'links' as 'index' and '_edit' as 'edit'. - Flattened the implementation by refactoring out some useless wrappers and other constructs. - Addressed continuation after triggered WARN_ON() on at the three sites that I've described in my email response to the previous patch set version. - Reworked keyring_read() so that it triggers the scheduler between the iterations. - Dropped "Assisted-by: LLM" tag because checkpatch.pl told me so. v2: - Tried to address all the issues pointed out by David and Eric. Tell me if something was ignored, as that would be an unintentional mishap. - Updated and trimmed the source code comments. - For assoc_array_edit I decided to go with two-element pointer array, which shifts a bit what David suggested. - Dropped is_keyring flag. It was so obvious call so I mention it here just in case because too obvious maxes out my self-doubt ;-) - Used cleanup.h primitives where I possibly could especially in order to make fallible initializations more bug-resistant. - The already-ack'd bug fixes are included but will be dropped as soon as I've sent them over to Linus. VERSIONS ======== - v4: https://lore.kernel.org/keyrings/20261029232437.2581640-1-jarkko@kernel.org/ - v3: https://lore.kernel.org/keyrings/20261025001105.1824178-1-jarkko@kernel.org/ - v2: https://lore.kernel.org/keyrings/20261023120953.1206778-1-jarkko@kernel.org/ - v1: https://lore.kernel.org/keyrings/20261016215326.4110064-1-jarkko@kernel.org/ Cc: bpf@vger.kernel.org Cc: dm-devel@lists.linux.dev Cc: fsverity@lists.linux.dev Cc: keyrings@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: Alasdair Kergon Cc: Alexei Starovoitov Cc: Alex Shi Cc: Andrew Morton Cc: Andrii Nakryiko Cc: Benjamin Marzinski Cc: Daniel Borkmann Cc: David Howells Cc: Dongliang Mu Cc: Eduard Zingerman Cc: Emil Tsalapatis Cc: Eric Biggers Cc: Ihor Solodrai Cc: James Morris Cc: Jarkko Sakkinen Cc: Jiri Olsa Cc: Jonathan Corbet Cc: Kumar Kartikeya Dwivedi Cc: Martin KaFai Lau Cc: Mike Snitzer Cc: Mikulas Patocka Cc: Paul Moore Cc: Randy Dunlap Cc: "Serge E. Hallyn" Cc: Shuah Khan Cc: Song Liu Cc: "Theodore Y. Ts'o" Cc: Yanteng Si Cc: Yonghong Song Jarkko Sakkinen (3): KEYS: Introduce keyring_is_empty() KEYS: Replace assoc_array with rhashtable lib: Remove assoc_array Documentation/core-api/assoc_array.rst | 564 ------ Documentation/core-api/index.rst | 1 - .../zh_CN/core-api/assoc_array.rst | 473 ----- .../translations/zh_CN/core-api/index.rst | 1 - drivers/md/dm-verity-verify-sig.c | 2 +- fs/verity/signature.c | 2 +- include/keys/keyring-type.h | 1 - include/linux/assoc_array.h | 88 - include/linux/assoc_array_priv.h | 178 -- include/linux/key-type.h | 1 - include/linux/key.h | 29 +- kernel/bpf/keys.c | 2 +- lib/Kconfig | 14 - lib/Makefile | 1 - lib/assoc_array.c | 1724 ----------------- security/keys/Kconfig | 1 - security/keys/internal.h | 14 +- security/keys/key.c | 22 +- security/keys/keyring.c | 994 +++++----- security/keys/request_key.c | 8 +- .../dm-verity/test-dm-verity-keyring.sh | 2 +- 21 files changed, 479 insertions(+), 3643 deletions(-) delete mode 100644 Documentation/core-api/assoc_array.rst delete mode 100644 Documentation/translations/zh_CN/core-api/assoc_array.rst delete mode 100644 include/linux/assoc_array.h delete mode 100644 include/linux/assoc_array_priv.h delete mode 100644 lib/assoc_array.c -- 2.47.3