From patchwork Fri Oct 29 09:58:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 12592511 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2318C433FE for ; Fri, 29 Oct 2021 10:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 800DF610C7 for ; Fri, 29 Oct 2021 10:59:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231849AbhJ2LCG (ORCPT ); Fri, 29 Oct 2021 07:02:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231740AbhJ2LCF (ORCPT ); Fri, 29 Oct 2021 07:02:05 -0400 Received: from baptiste.telenet-ops.be (baptiste.telenet-ops.be [IPv6:2a02:1800:120:4::f00:13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A29AFC061745 for ; Fri, 29 Oct 2021 03:59:36 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed20:20b9:ea2a:8e1c:8da1]) by baptiste.telenet-ops.be with bizsmtp id BmzY2600c01kgUz01mzYHe; Fri, 29 Oct 2021 12:59:33 +0200 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 1mgPbg-008ir7-JA; Fri, 29 Oct 2021 12:59:32 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1mgOeP-00FCmn-90; Fri, 29 Oct 2021 11:58:17 +0200 From: Geert Uytterhoeven To: Thomas Bogendoerfer , Markos Chandras , Ralf Baechle Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] mips: cm: Convert to bitfield API to fix out-of-bounds access Date: Fri, 29 Oct 2021 11:58:16 +0200 Message-Id: <0471c545117c5fa05bd9c73005cda9b74608a61e.1635501373.git.geert+renesas@glider.be> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org mips_cm_error_report() extracts the cause and other cause from the error register using shifts. This works fine for the former, as it is stored in the top bits, and the shift will thus remove all non-related bits. However, the latter is stored in the bottom bits, hence thus needs masking to get rid of non-related bits. Without such masking, using it as an index into the cm2_causes[] array will lead to an out-of-bounds access, probably causing a crash. Fix this by using FIELD_GET() instead. Bite the bullet and convert all MIPS CM handling to the bitfield API, to improve readability and safety. Fixes: 3885c2b463f6a236 ("MIPS: CM: Add support for reporting CM cache errors") Signed-off-by: Geert Uytterhoeven Reviewed-by: Jiaxun Yang --- Compile-tested only, but assembler output before/after compared. --- arch/mips/include/asm/mips-cm.h | 12 ++++++------ arch/mips/kernel/mips-cm.c | 21 ++++++++++----------- 2 files changed, 16 insertions(+), 17 deletions(-) diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h index aeae2effa123d7e2..23c67c0871b17c91 100644 --- a/arch/mips/include/asm/mips-cm.h +++ b/arch/mips/include/asm/mips-cm.h @@ -11,6 +11,7 @@ #ifndef __MIPS_ASM_MIPS_CM_H__ #define __MIPS_ASM_MIPS_CM_H__ +#include #include #include @@ -153,8 +154,8 @@ GCR_ACCESSOR_RO(32, 0x030, rev) #define CM_GCR_REV_MINOR GENMASK(7, 0) #define CM_ENCODE_REV(major, minor) \ - (((major) << __ffs(CM_GCR_REV_MAJOR)) | \ - ((minor) << __ffs(CM_GCR_REV_MINOR))) + (FIELD_PREP(CM_GCR_REV_MAJOR, major) | \ + FIELD_PREP(CM_GCR_REV_MINOR, minor)) #define CM_REV_CM2 CM_ENCODE_REV(6, 0) #define CM_REV_CM2_5 CM_ENCODE_REV(7, 0) @@ -362,10 +363,10 @@ static inline int mips_cm_revision(void) static inline unsigned int mips_cm_max_vp_width(void) { extern int smp_num_siblings; - uint32_t cfg; if (mips_cm_revision() >= CM_REV_CM3) - return read_gcr_sys_config2() & CM_GCR_SYS_CONFIG2_MAXVPW; + return FIELD_GET(CM_GCR_SYS_CONFIG2_MAXVPW, + read_gcr_sys_config2()); if (mips_cm_present()) { /* @@ -373,8 +374,7 @@ static inline unsigned int mips_cm_max_vp_width(void) * number of VP(E)s, and if that ever changes then this will * need revisiting. */ - cfg = read_gcr_cl_config() & CM_GCR_Cx_CONFIG_PVPE; - return (cfg >> __ffs(CM_GCR_Cx_CONFIG_PVPE)) + 1; + return FIELD_GET(CM_GCR_Cx_CONFIG_PVPE, read_gcr_cl_config()) + 1; } if (IS_ENABLED(CONFIG_SMP)) diff --git a/arch/mips/kernel/mips-cm.c b/arch/mips/kernel/mips-cm.c index 90f1c3df1f0e495e..b4f7d950c84680d3 100644 --- a/arch/mips/kernel/mips-cm.c +++ b/arch/mips/kernel/mips-cm.c @@ -221,8 +221,7 @@ static void mips_cm_probe_l2sync(void) phys_addr_t addr; /* L2-only sync was introduced with CM major revision 6 */ - major_rev = (read_gcr_rev() & CM_GCR_REV_MAJOR) >> - __ffs(CM_GCR_REV_MAJOR); + major_rev = FIELD_GET(CM_GCR_REV_MAJOR, read_gcr_rev()); if (major_rev < 6) return; @@ -306,13 +305,13 @@ void mips_cm_lock_other(unsigned int cluster, unsigned int core, preempt_disable(); if (cm_rev >= CM_REV_CM3) { - val = core << __ffs(CM3_GCR_Cx_OTHER_CORE); - val |= vp << __ffs(CM3_GCR_Cx_OTHER_VP); + val = FIELD_PREP(CM3_GCR_Cx_OTHER_CORE, core) | + FIELD_PREP(CM3_GCR_Cx_OTHER_VP, vp); if (cm_rev >= CM_REV_CM3_5) { val |= CM_GCR_Cx_OTHER_CLUSTER_EN; - val |= cluster << __ffs(CM_GCR_Cx_OTHER_CLUSTER); - val |= block << __ffs(CM_GCR_Cx_OTHER_BLOCK); + val |= FIELD_PREP(CM_GCR_Cx_OTHER_CLUSTER, cluster); + val |= FIELD_PREP(CM_GCR_Cx_OTHER_BLOCK, block); } else { WARN_ON(cluster != 0); WARN_ON(block != CM_GCR_Cx_OTHER_BLOCK_LOCAL); @@ -342,7 +341,7 @@ void mips_cm_lock_other(unsigned int cluster, unsigned int core, spin_lock_irqsave(&per_cpu(cm_core_lock, curr_core), per_cpu(cm_core_lock_flags, curr_core)); - val = core << __ffs(CM_GCR_Cx_OTHER_CORENUM); + val = FIELD_PREP(CM_GCR_Cx_OTHER_CORENUM, core); } write_gcr_cl_other(val); @@ -386,8 +385,8 @@ void mips_cm_error_report(void) cm_other = read_gcr_error_mult(); if (revision < CM_REV_CM3) { /* CM2 */ - cause = cm_error >> __ffs(CM_GCR_ERROR_CAUSE_ERRTYPE); - ocause = cm_other >> __ffs(CM_GCR_ERROR_MULT_ERR2ND); + cause = FIELD_GET(CM_GCR_ERROR_CAUSE_ERRTYPE, cm_error); + ocause = FIELD_GET(CM_GCR_ERROR_MULT_ERR2ND, cm_other); if (!cause) return; @@ -445,8 +444,8 @@ void mips_cm_error_report(void) ulong core_id_bits, vp_id_bits, cmd_bits, cmd_group_bits; ulong cm3_cca_bits, mcp_bits, cm3_tr_bits, sched_bit; - cause = cm_error >> __ffs64(CM3_GCR_ERROR_CAUSE_ERRTYPE); - ocause = cm_other >> __ffs(CM_GCR_ERROR_MULT_ERR2ND); + cause = FIELD_GET(CM3_GCR_ERROR_CAUSE_ERRTYPE, cm_error); + ocause = FIELD_GET(CM_GCR_ERROR_MULT_ERR2ND, cm_other); if (!cause) return;