From patchwork Mon Jan 31 13:26:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 12730689 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 54CC7C433FE for ; Mon, 31 Jan 2022 13:26:51 +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=PAfwxYx6v/j15vOEFxM/NRpCb+Px1FUAY9uieAPoyMU=; b=nCWrsoI08lfUTb Y7b/0RRZ00NbW7z4ueUNJu2xPJW3a6n58xPxCUAUcpx8hDQ703fSVwzCxGL3yUQgW3FVU55XCnnkm 6yQn2sewRtFh+h7tFRcpLN08pmab5tAVusvXIUkEMjuaXGCBW00UvtpeNIwe+WJfpsNaPsjQ0Rwa1 tqHd+xymYUwmpVSEZIVNycFl1wYW3Doz1XArC1qp8+lG60xBuFa51DVUlvg3kC6yBepzUCVpfaFNg 9G5EfjTnzKxMC8882g7vObjGgbz5DJcKIaswn7sfJl0z9/82G58vna8f9yJLQzOYP6BMIQSLqLxku dhm2IAkT0bHb76h2zPzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nEWhf-009Trc-Eu; Mon, 31 Jan 2022 13:26:43 +0000 Received: from michel.telenet-ops.be ([2a02:1800:110:4::f00:18]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nEWhW-009TnO-FX for linux-riscv@lists.infradead.org; Mon, 31 Jan 2022 13:26:37 +0000 Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed40:58b3:216b:d287:833]) by michel.telenet-ops.be with bizsmtp id pRSU2600Z2lsq0X06RSUsE; Mon, 31 Jan 2022 14:26:29 +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 1nEWhQ-00CaWA-JM; Mon, 31 Jan 2022 14:26:28 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1nEWhQ-00H7Gl-2i; Mon, 31 Jan 2022 14:26:28 +0100 From: Geert Uytterhoeven To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Atish Patra Cc: Jessica Clarke , Emil Renner Berthing , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH 3/3] RISC-V: Fix IPI/RFENCE hmask on non-monotonic hartid ordering Date: Mon, 31 Jan 2022 14:26:22 +0100 Message-Id: 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-20220131_052634_686943_9C8FDD08 X-CRM114-Status: GOOD ( 17.02 ) 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: Atish Patra --- 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); }