From nobody Thu Apr 3 11:46:28 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1742885676461845.9493211179607; Mon, 24 Mar 2025 23:54:36 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1twyBC-0001U6-JE; Tue, 25 Mar 2025 02:54:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1twy9c-0006Ny-Ji; Tue, 25 Mar 2025 02:52:55 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1twy9Z-0001yQ-IV; Tue, 25 Mar 2025 02:52:52 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id EA68A107D7E; Tue, 25 Mar 2025 09:49:33 +0300 (MSK) Received: from gandalf.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id 8D12A1D5E89; Tue, 25 Mar 2025 09:50:43 +0300 (MSK) Received: by gandalf.tls.msk.ru (Postfix, from userid 1000) id 80C175705A; Tue, 25 Mar 2025 09:50:43 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Richard Henderson , Andreas Schwab , Alistair Francis , Michael Tokarev Subject: [Stable-9.2.3 60/69] linux-user/riscv: Fix handling of cpu mask in riscv_hwprobe syscall Date: Tue, 25 Mar 2025 09:50:33 +0300 Message-Id: <20250325065043.3263864-9-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1742885678610019000 Content-Type: text/plain; charset="utf-8" From: Richard Henderson The third argument of the syscall contains the size of the cpu mask in bytes, not bits. Nor is the size rounded up to a multiple of sizeof(abi_ulong). Cc: qemu-stable@nongnu.org Reported-by: Andreas Schwab Fixes: 9e1c7d982d7 ("linux-user/riscv: Add syscall riscv_hwprobe") Signed-off-by: Richard Henderson Reviewed-by: Alistair Francis Message-ID: <20250308225902.1208237-3-richard.henderson@linaro.org> Signed-off-by: Alistair Francis (cherry picked from commit 1a010d22b7adecf0fb1c069e1e535af1aa51e9cf) Signed-off-by: Michael Tokarev diff --git a/linux-user/syscall.c b/linux-user/syscall.c index a407d4a023..549e39e196 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -9097,35 +9097,38 @@ static void risc_hwprobe_fill_pairs(CPURISCVState *= env, } } =20 -static int cpu_set_valid(abi_long arg3, abi_long arg4) +/* + * If the cpumask_t of (target_cpus, cpusetsize) cannot be read: -EFAULT. + * If the cpumast_t has no bits set: -EINVAL. + * Otherwise the cpumask_t contains some bit set: 0. + * Unlike the kernel, we do not mask cpumask_t by the set of online cpus, + * nor bound the search by cpumask_size(). + */ +static int nonempty_cpu_set(abi_ulong cpusetsize, abi_ptr target_cpus) { - int ret, i, tmp; - size_t host_mask_size, target_mask_size; - unsigned long *host_mask; - - /* - * cpu_set_t represent CPU masks as bit masks of type unsigned long *. - * arg3 contains the cpu count. - */ - tmp =3D (8 * sizeof(abi_ulong)); - target_mask_size =3D ((arg3 + tmp - 1) / tmp) * sizeof(abi_ulong); - host_mask_size =3D (target_mask_size + (sizeof(*host_mask) - 1)) & - ~(sizeof(*host_mask) - 1); - - host_mask =3D alloca(host_mask_size); - - ret =3D target_to_host_cpu_mask(host_mask, host_mask_size, - arg4, target_mask_size); - if (ret !=3D 0) { - return ret; - } + unsigned char *p =3D lock_user(VERIFY_READ, target_cpus, cpusetsize, 1= ); + int ret =3D -TARGET_EFAULT; =20 - for (i =3D 0 ; i < host_mask_size / sizeof(*host_mask); i++) { - if (host_mask[i] !=3D 0) { - return 0; + if (p) { + ret =3D -TARGET_EINVAL; + /* + * Since we only care about the empty/non-empty state of the cpuma= sk_t + * not the individual bits, we do not need to repartition the bits + * from target abi_ulong to host unsigned long. + * + * Note that the kernel does not round up cpusetsize to a multiple= of + * sizeof(abi_ulong). After bounding cpusetsize by cpumask_size(), + * it copies exactly cpusetsize bytes into a zeroed buffer. + */ + for (abi_ulong i =3D 0; i < cpusetsize; ++i) { + if (p[i]) { + ret =3D 0; + break; + } } + unlock_user(p, target_cpus, 0); } - return -TARGET_EINVAL; + return ret; } =20 static abi_long do_riscv_hwprobe(CPUArchState *cpu_env, abi_long arg1, @@ -9142,7 +9145,7 @@ static abi_long do_riscv_hwprobe(CPUArchState *cpu_en= v, abi_long arg1, =20 /* check cpu_set */ if (arg3 !=3D 0) { - ret =3D cpu_set_valid(arg3, arg4); + ret =3D nonempty_cpu_set(arg3, arg4); if (ret !=3D 0) { return ret; } --=20 2.39.5