From nobody Mon Jun 29 23:55:45 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45315C433EF for ; Mon, 31 Jan 2022 13:26:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378751AbiAaN0h (ORCPT ); Mon, 31 Jan 2022 08:26:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358902AbiAaN0c (ORCPT ); Mon, 31 Jan 2022 08:26:32 -0500 Received: from michel.telenet-ops.be (michel.telenet-ops.be [IPv6:2a02:1800:110:4::f00:18]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BB1FC06173E for ; Mon, 31 Jan 2022 05:26:31 -0800 (PST) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed40:58b3:216b:d287:833]) by michel.telenet-ops.be with bizsmtp id pRSU2600Y2lsq0X06RSUsD; 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-00CaW8-Gp; Mon, 31 Jan 2022 14:26:28 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1nEWhP-00H7GX-Vd; Mon, 31 Jan 2022 14:26:27 +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 1/3] RISC-V: Fix hartid mask handling for hartid 31 and up Date: Mon, 31 Jan 2022 14:26:20 +0100 Message-Id: <48231bc6ef385e0057f34cfb71854d8e8fd02f66.1643635156.git.geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Jessica reports that using "1 << hartid" causes undefined behavior for hartid 31 and up. Fix this by using the BIT() helper instead of an explicit shift. Reported-by: Jessica Clarke Fixes: 26fb751ca37846c9 ("RISC-V: Do not use cpumask data structure for har= tid bitmap") Signed-off-by: Geert Uytterhoeven Tested-by: Emil Renner Berthing --- arch/riscv/kernel/sbi.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index f72527fcb34709a6..f93bc75f2bc43c8e 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -5,6 +5,7 @@ * Copyright (c) 2020 Western Digital Corporation or its affiliates. */ =20 +#include #include #include #include @@ -85,7 +86,7 @@ static unsigned long __sbi_v01_cpumask_to_hartmask(const = struct cpumask *cpu_mas pr_warn("Unable to send any request to hartid > BITS_PER_LONG for SBI v= 0.1\n"); break; } - hmask |=3D 1 << hartid; + hmask |=3D BIT(hartid); } =20 return hmask; @@ -268,7 +269,7 @@ static int __sbi_send_ipi_v02(const struct cpumask *cpu= _mask) } if (!hmask) hbase =3D hartid; - hmask |=3D 1UL << (hartid - hbase); + hmask |=3D BIT(hartid - hbase); } =20 if (hmask) { @@ -362,7 +363,7 @@ static int __sbi_rfence_v02(int fid, const struct cpuma= sk *cpu_mask, } if (!hmask) hbase =3D hartid; - hmask |=3D 1UL << (hartid - hbase); + hmask |=3D BIT(hartid - hbase); } =20 if (hmask) { --=20 2.25.1 From nobody Mon Jun 29 23:55:45 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF8ACC433F5 for ; Mon, 31 Jan 2022 13:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378756AbiAaN0j (ORCPT ); Mon, 31 Jan 2022 08:26:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378693AbiAaN0c (ORCPT ); Mon, 31 Jan 2022 08:26:32 -0500 Received: from albert.telenet-ops.be (albert.telenet-ops.be [IPv6:2a02:1800:110:4::f00:1a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31CDDC061401 for ; Mon, 31 Jan 2022 05:26:31 -0800 (PST) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed40:58b3:216b:d287:833]) by albert.telenet-ops.be with bizsmtp id pRSU2600d2lsq0X06RSVqN; 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-00CaW9-NV; Mon, 31 Jan 2022 14:26:28 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1nEWhQ-00H7Ge-1C; 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 2/3] RISC-V: Fix handling of empty cpu masks Date: Mon, 31 Jan 2022 14:26:21 +0100 Message-Id: <35936f19a9727b14e4fdb7f5fadfabfa29d53d96.1643635156.git.geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The cpumask rework slightly changed the behavior of the code. Fix this by treating an empty cpumask as meaning all online CPUs. Extracted from a patch by Atish Patra . Reported-by: Jessica Clarke Fixes: 26fb751ca37846c9 ("RISC-V: Do not use cpumask data structure for har= tid bitmap") Signed-off-by: Geert Uytterhoeven Reviewed-by: Atish Patra Tested-by: Emil Renner Berthing --- arch/riscv/kernel/sbi.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index f93bc75f2bc43c8e..22444cfcd56cc646 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -161,7 +161,7 @@ static int __sbi_send_ipi_v01(const struct cpumask *cpu= _mask) { unsigned long hart_mask; =20 - if (!cpu_mask) + if (!cpu_mask || cpumask_empty(cpu_mask)) cpu_mask =3D cpu_online_mask; hart_mask =3D __sbi_v01_cpumask_to_hartmask(cpu_mask); =20 @@ -177,7 +177,7 @@ static int __sbi_rfence_v01(int fid, const struct cpuma= sk *cpu_mask, int result =3D 0; unsigned long hart_mask; =20 - if (!cpu_mask) + if (!cpu_mask || cpumask_empty(cpu_mask)) cpu_mask =3D cpu_online_mask; hart_mask =3D __sbi_v01_cpumask_to_hartmask(cpu_mask); =20 @@ -254,7 +254,7 @@ static int __sbi_send_ipi_v02(const struct cpumask *cpu= _mask) struct sbiret ret =3D {0}; int result; =20 - if (!cpu_mask) + if (!cpu_mask || cpumask_empty(cpu_mask)) cpu_mask =3D cpu_online_mask; =20 for_each_cpu(cpuid, cpu_mask) { @@ -348,7 +348,7 @@ static int __sbi_rfence_v02(int fid, const struct cpuma= sk *cpu_mask, unsigned long hartid, cpuid, hmask =3D 0, hbase =3D 0; int result; =20 - if (!cpu_mask) + if (!cpu_mask || cpumask_empty(cpu_mask)) cpu_mask =3D cpu_online_mask; =20 for_each_cpu(cpuid, cpu_mask) { --=20 2.25.1 From nobody Mon Jun 29 23:55:45 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4E57C433F5 for ; Mon, 31 Jan 2022 13:26:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378722AbiAaN0g (ORCPT ); Mon, 31 Jan 2022 08:26:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229625AbiAaN0c (ORCPT ); Mon, 31 Jan 2022 08:26:32 -0500 Received: from michel.telenet-ops.be (michel.telenet-ops.be [IPv6:2a02:1800:110:4::f00:18]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19BE8C06173B for ; Mon, 31 Jan 2022 05:26:31 -0800 (PST) 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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 har= tid bitmap") Signed-off-by: Geert Uytterhoeven Reviewed-by: Atish Patra Tested-by: Atish Patra Tested-by: Emil Renner Berthing --- 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) =20 static int __sbi_send_ipi_v02(const struct cpumask *cpu_mask) { - unsigned long hartid, cpuid, hmask =3D 0, hbase =3D 0; + unsigned long hartid, cpuid, hmask =3D 0, hbase =3D 0, htop =3D 0; struct sbiret ret =3D {0}; int result; =20 @@ -259,16 +259,27 @@ static int __sbi_send_ipi_v02(const struct cpumask *c= pu_mask) =20 for_each_cpu(cpuid, cpu_mask) { hartid =3D cpuid_to_hartid_map(cpuid); - if (hmask && ((hbase + BITS_PER_LONG) <=3D hartid)) { - ret =3D sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI, - hmask, hbase, 0, 0, 0, 0); - if (ret.error) - goto ecall_failed; - hmask =3D 0; - hbase =3D 0; + if (hmask) { + if (hartid + BITS_PER_LONG <=3D htop || + hbase + BITS_PER_LONG <=3D hartid) { + ret =3D sbi_ecall(SBI_EXT_IPI, + SBI_EXT_IPI_SEND_IPI, hmask, + hbase, 0, 0, 0, 0); + if (ret.error) + goto ecall_failed; + hmask =3D 0; + } else if (hartid < hbase) { + /* shift the mask to fit lower hartid */ + hmask <<=3D hbase - hartid; + hbase =3D hartid; + } } - if (!hmask) + if (!hmask) { hbase =3D hartid; + htop =3D hartid; + } else if (hartid > htop) { + htop =3D hartid; + } hmask |=3D BIT(hartid - hbase); } =20 @@ -345,7 +356,7 @@ static int __sbi_rfence_v02(int fid, const struct cpuma= sk *cpu_mask, unsigned long start, unsigned long size, unsigned long arg4, unsigned long arg5) { - unsigned long hartid, cpuid, hmask =3D 0, hbase =3D 0; + unsigned long hartid, cpuid, hmask =3D 0, hbase =3D 0, htop =3D 0; int result; =20 if (!cpu_mask || cpumask_empty(cpu_mask)) @@ -353,16 +364,26 @@ static int __sbi_rfence_v02(int fid, const struct cpu= mask *cpu_mask, =20 for_each_cpu(cpuid, cpu_mask) { hartid =3D cpuid_to_hartid_map(cpuid); - if (hmask && ((hbase + BITS_PER_LONG) <=3D hartid)) { - result =3D __sbi_rfence_v02_call(fid, hmask, hbase, - start, size, arg4, arg5); - if (result) - return result; - hmask =3D 0; - hbase =3D 0; + if (hmask) { + if (hartid + BITS_PER_LONG <=3D htop || + hbase + BITS_PER_LONG <=3D hartid) { + result =3D __sbi_rfence_v02_call(fid, hmask, + hbase, start, size, arg4, arg5); + if (result) + return result; + hmask =3D 0; + } else if (hartid < hbase) { + /* shift the mask to fit lower hartid */ + hmask <<=3D hbase - hartid; + hbase =3D hartid; + } } - if (!hmask) + if (!hmask) { hbase =3D hartid; + htop =3D hartid; + } else if (hartid > htop) { + htop =3D hartid; + } hmask |=3D BIT(hartid - hbase); } =20 --=20 2.25.1