From patchwork Wed Feb 9 08:54:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 12739865 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2E61AC433F5 for ; Wed, 9 Feb 2022 08:55:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3UPe/sYtyPhkHtHAluTRTA6cZ1jrIkG4XOQJ1NHfxoQ=; b=0JFmkT4OByKTQr R9MD6+/lCQOz61vKOAKlagLLutOo2RJsbf/ZWwWYdtw3j3pZoTcJ65x1cVFM93YOc/lVQdUPBCHYl 71do8I4gkFcrhtDITbOr5pDvlaVxM6MOCRUT9IGgKm4TeXaTHyJfKIBxLP53xYx3jUEX2vx8b+I72 IX7gp3OCJyC2CjRqiCT/k9E29QIz0h+lgBcT5rXKEk3GgGuOth/21Zrdt6Q4lfuXfwsB0vBARiLAk hj4seMNtllKSpP1NaFpfD/zykof4iLbA2JkWHpOLvpoSey5LmYBtegTfao7O0b+ZLG+F1Il8MMFjM 02mQKKL9U95ethNVUOTw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHil6-00Gkhz-Ch; Wed, 09 Feb 2022 08:55:28 +0000 Received: from andre.telenet-ops.be ([2a02:1800:120:4::f00:15]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHijq-00Gk7h-CY for linux-riscv@lists.infradead.org; Wed, 09 Feb 2022 08:54:12 +0000 Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed40:54c7:c522:3859:290]) by andre.telenet-ops.be with bizsmtp id swu32600Y4VQqf501wu3YL; Wed, 09 Feb 2022 09:54:04 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nHijj-000DIj-AL; Wed, 09 Feb 2022 09:54:03 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1nHiji-00DkM0-OH; Wed, 09 Feb 2022 09:54:02 +0100 From: Geert Uytterhoeven To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: Atish Patra , Jessica Clarke , Anup Patel , Emil Renner Berthing , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v2 3/3] RISC-V: Fix IPI/RFENCE hmask on non-monotonic hartid ordering Date: Wed, 9 Feb 2022 09:54:01 +0100 Message-Id: <84ee1ae4bfc0ddbafdb38a21135f67ceb121c5e1.1644396407.git.geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220209_005410_671495_54369AF7 X-CRM114-Status: GOOD ( 16.92 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org If the boot CPU does not have the lowest hartid, "hartid - hbase" can become negative, leading to an incorrect hmask, causing userspace to crash with SEGV. This is observed on e.g. Starlight Beta, where cpuid 1 maps to hartid 0, and cpuid 0 maps to hartid 1. Fix this by detecting this case, and shifting the accumulated mask and updating hbase, if possible. Fixes: 26fb751ca37846c9 ("RISC-V: Do not use cpumask data structure for hartid bitmap") Signed-off-by: Geert Uytterhoeven Reviewed-by: Atish Patra Tested-by: Emil Renner Berthing Tested-by: Atish Patra --- v2: - Add Reviewed-by, Tested-by. --- arch/riscv/kernel/sbi.c | 57 ++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 18 deletions(-) diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 22444cfcd56cc646..775d3322b422fe14 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -250,7 +250,7 @@ static void __sbi_set_timer_v02(uint64_t stime_value) static int __sbi_send_ipi_v02(const struct cpumask *cpu_mask) { - unsigned long hartid, cpuid, hmask = 0, hbase = 0; + unsigned long hartid, cpuid, hmask = 0, hbase = 0, htop = 0; struct sbiret ret = {0}; int result; @@ -259,16 +259,27 @@ static int __sbi_send_ipi_v02(const struct cpumask *cpu_mask) for_each_cpu(cpuid, cpu_mask) { hartid = cpuid_to_hartid_map(cpuid); - if (hmask && ((hbase + BITS_PER_LONG) <= hartid)) { - ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI, - hmask, hbase, 0, 0, 0, 0); - if (ret.error) - goto ecall_failed; - hmask = 0; - hbase = 0; + if (hmask) { + if (hartid + BITS_PER_LONG <= htop || + hbase + BITS_PER_LONG <= hartid) { + ret = sbi_ecall(SBI_EXT_IPI, + SBI_EXT_IPI_SEND_IPI, hmask, + hbase, 0, 0, 0, 0); + if (ret.error) + goto ecall_failed; + hmask = 0; + } else if (hartid < hbase) { + /* shift the mask to fit lower hartid */ + hmask <<= hbase - hartid; + hbase = hartid; + } } - if (!hmask) + if (!hmask) { hbase = hartid; + htop = hartid; + } else if (hartid > htop) { + htop = hartid; + } hmask |= BIT(hartid - hbase); } @@ -345,7 +356,7 @@ static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask, unsigned long start, unsigned long size, unsigned long arg4, unsigned long arg5) { - unsigned long hartid, cpuid, hmask = 0, hbase = 0; + unsigned long hartid, cpuid, hmask = 0, hbase = 0, htop = 0; int result; if (!cpu_mask || cpumask_empty(cpu_mask)) @@ -353,16 +364,26 @@ static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask, for_each_cpu(cpuid, cpu_mask) { hartid = cpuid_to_hartid_map(cpuid); - if (hmask && ((hbase + BITS_PER_LONG) <= hartid)) { - result = __sbi_rfence_v02_call(fid, hmask, hbase, - start, size, arg4, arg5); - if (result) - return result; - hmask = 0; - hbase = 0; + if (hmask) { + if (hartid + BITS_PER_LONG <= htop || + hbase + BITS_PER_LONG <= hartid) { + result = __sbi_rfence_v02_call(fid, hmask, + hbase, start, size, arg4, arg5); + if (result) + return result; + hmask = 0; + } else if (hartid < hbase) { + /* shift the mask to fit lower hartid */ + hmask <<= hbase - hartid; + hbase = hartid; + } } - if (!hmask) + if (!hmask) { hbase = hartid; + htop = hartid; + } else if (hartid > htop) { + htop = hartid; + } hmask |= BIT(hartid - hbase); }