From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AE1C0606A321 for ; Sun, 8 Nov 2026 11:43:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=S0cw5gtW Received: by kanga.kvack.org (Postfix) id AECF66B05B0; Sun, 8 Nov 2026 06:43:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A98A46B05B1; Sun, 8 Nov 2026 06:43:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9B1476B05B2; Sun, 8 Nov 2026 06:43:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 74EF06B05B0 for ; Sun, 8 Nov 2026 06:43:36 -0500 (EST) Received: from smtpin22.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 69E3E1A01F2 for ; Sun, 8 Nov 2026 11:43:35 +0000 (UTC) X-FDA: 85411766790.22.29D63B2 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf11.hostedemail.com (Postfix) with ESMTP id DD42740003 for ; Sun, 8 Nov 2026 11:43:33 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=fail ("headers rsa verify failed") header.d=kernel.org header.s=k20260515 header.b=S0cw5gtW; spf=pass (imf11.hostedemail.com: domain of sashiko-bot@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sashiko-bot@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=1794138214; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=VwQGFsaaCoMROSPE2Da/1tMfn7BcmAloMkj2bJskjEI=; b=GXnmTs3bHwVI9VvY3u4hHCRSoOZ2d7Qel6NsA2Z1Avby6BHDYmUMFhZKBrN9SEApU3maxq V6F0UOtDFy4fZR08M5a0yGyt34yH3bVqYbEzmkCfr1CLJw6FUwyBKTk0fF6T7hK3fLK9iv mUiiKlOCrq2wtYRcti81yM/hHyi2+po= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1794138214; b=G1i38N4SjPvvOxDusSGn0eK1JWJeCSEvGcNJzLzVBLgTxFfwTia4oLx3Z9OLz4L+9azTEZ U86sRgThUfbrMI7y6Z4hFuOyq/TT65OIdzI7BzHLDfFGJO4EGpiQQy+B8Q7qydc+mDzeK1 bTUI/8CLn94Op2h67PojqAmD1SQvpos= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=fail ("headers rsa verify failed") header.d=kernel.org header.s=k20260515 header.b=S0cw5gtW; spf=pass (imf11.hostedemail.com: domain of sashiko-bot@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sashiko-bot@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id D41016133E; Sun, 8 Nov 2026 11:43:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8753C1F0089F; Sun, 8 Nov 2026 11:43:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794138212; bh=VwQGFsaaCoMROSPE2Da/1tMfn7BcmAloMkj2bJskjEI=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=S0cw5gtW/h9wOfpi24c0z4XXuiTegGbNkIAjQrt++QxS99ghrd3J8Kjn2UokX7how K6pRsO6eavp4mb/tlvZYnEp+IavUbQOxbBMFR1UYa1Uk63F3i2fms+alNUOuGQ8ivO HW2uA/5z3dYQUubfN7n29Gyff6QIpuWu6ad1gJr21bN7rBsmEJ9CrZw58xOnEn/fVo l2P05CqSaYSPPGMGKhVDsHUGfGkYlahiE9mts6LvxG7V+G6w3RQi9ARq982fiiW34t pG64Uy9lv9nvE7RJMq28VoRTIvRDFkGkmACgsabYqrxFbMHFHLhpVGtKikFiIGFGa1 uoONW16Tdyznw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v9 1/3] riscv: implement this_cpu operations Reply-To: sashiko-reviews@lists.linux.dev To: "Yunhui Cui" , pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, dennis@kernel.org, tj@kernel.org, cl@gentwo.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, memxor@gmail.com, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, bjorn@kernel.org, pulehui@huawei.com, puranjay@kernel.org, thuth@redhat.com, ajones@ventanamicro.com, ben.dooks@codethink.co.uk, rkrcmar@ventanamicro.com, samuel.holland@sifive.com, zong.li@sifive.com, conor.dooley@microchip.com, tglx@kernel.org, debug@rivosinc.com, seanwascoding@gmail.com, andybnac@gmail.com, menglong8.dong@gmail.com, cyrilbur@tenstorrent.com, wangruikang@iscas.ac.cn, atishp@rivosinc.com, apatel@ventanamicro.com, linux-mm@kvack.org, bpf@vger.kernel.org, arnd@arndb.de, nathan@kernel.org, nick.desaulniers+lkml@gmail.com, morbo@google.com, justinstitt@google.com, qingfang.deng@siflower.com.cn, dave@stgolabs.net, emil@etsalap atis.com , ihor.solodrai@linux.dev, broonie@kernel.org In-Reply-To: <20261108110406.97495-2-cuiyunhui@bytedance.com> References: <20261108110406.97495-1-cuiyunhui@bytedance.com> <20261108110406.97495-2-cuiyunhui@bytedance.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 08 Nov 2026 11:43:30 +0000 X-Stat-Signature: jw4htug4wpt6utxj1aj5boeghat3x7gu X-Rspamd-Queue-Id: DD42740003 X-Rspam-User: X-Rspamd-Server: rspam08 X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1794138213-471475 X-HE-Meta: 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 ki2QfBPL 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: Thank you for your contribution! Sashiko AI review found 1 potential issue to consider: - [Low] riscv: percpu: typeof(pcp) retains __percpu and const qualifiers in locals -- commit 9753271dee3a084b7bff8ad7ad29d76cb64e49f4 Author: Yunhui Cui riscv: implement this_cpu operations This commit implements RISC-V-specific this_cpu operations using preemption disablement and relaxed AMOs (or 32-bit LR/SC for 8-bit and 16-bit accesses when Zabha is unavailable). Link: https://lore.kernel.org/r/20260826010748.zphu3wh2hlm4t4o2@offworld > diff --git a/arch/riscv/include/asm/percpu.h b/arch/riscv/include/asm/per= cpu.h > new file mode 100644 > index 0000000000000..280b122b9fe69 > --- /dev/null > +++ b/arch/riscv/include/asm/percpu.h [ ... ] > +#define _pcp_protect_return(op, pcp, args...) \ > +({ \ > + typeof(pcp) __retval; \ > + preempt_disable_notrace(); \ > + __retval =3D (typeof(pcp))op(raw_cpu_ptr(&(pcp)), ##args); \ > + preempt_enable_notrace(); \ > + __retval; \ > +}) > + > +#define _pcp_protect_cmpxchg_return(op, pcp, old, new) \ > +({ \ > + typeof(pcp) __retval; \ > + typeof(pcp) *__pcp_ptr; \ > + \ > + preempt_disable_notrace(); \ > + __pcp_ptr =3D raw_cpu_ptr(&(pcp)); \ > + instrument_atomic_read_write(__pcp_ptr, sizeof(*__pcp_ptr)); \ > + __retval =3D (typeof(pcp))op(__pcp_ptr, (unsigned long)(old), \ > + (unsigned long)(new)); \ > + preempt_enable_notrace(); \ > + __retval; \ > +}) [ ... ] > +#define this_cpu_cmpxchg128(pcp, o, n) \ > +({ \ > + u128 old__ =3D (o), new__ =3D (n), ret__; \ > + typeof(pcp) *ptr__; \ > + \ > + preempt_disable_notrace(); \ > + ptr__ =3D raw_cpu_ptr(&(pcp)); \ > + if (system_has_cmpxchg128()) \ > + ret__ =3D cmpxchg128_local(ptr__, old__, new__); \ > + else \ > + ret__ =3D __percpu_generic_cmpxchg128(ptr__, old__, new__); \ > + preempt_enable_notrace(); \ > + ret__; \ > +}) [Severity: Low] Should _pcp_protect_return(), _pcp_protect_cmpxchg_return(), and this_cpu_cmpxchg128() use TYPEOF_UNQUAL(pcp) instead of typeof(pcp) for their local variables and pointers? typeof(pcp) retains the __percpu address-space and const qualifiers from pcp. Because raw_cpu_ptr() strips __percpu via PERCPU_PTR() (since commit 6a39fe05ecaa ("percpu: use TYPEOF_UNQUAL() in *_cpu_ptr() accessors")), declaring __pcp_ptr and ptr__ with typeof(pcp) * leaves them in the __percpu address space and triggers sparse address-space mismatch warnings on assignment from raw_cpu_ptr() and when passing them to helpers taking regular pointers. Retaining const on __retval also causes a build error if this_cpu_read() is used on a const per-CPU variable. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261108110406.9749= 5-1-cuiyunhui@bytedance.com?part=3D1