From nobody Mon Feb 9 04:56:46 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 48401C04A6A for ; Fri, 11 Aug 2023 23:36:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237187AbjHKXgT (ORCPT ); Fri, 11 Aug 2023 19:36:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237089AbjHKXgG (ORCPT ); Fri, 11 Aug 2023 19:36:06 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 578D710E6 for ; Fri, 11 Aug 2023 16:36:06 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id 41be03b00d2f7-564f73e2c59so3068183a12.2 for ; Fri, 11 Aug 2023 16:36:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1691796966; x=1692401766; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=uqSttns2QMMHKhEq1iT/6N0civk3/DgixVYj3d7z750=; b=X34fuYj30ll5ylhB7Aqg1vD8KbeZ19k7cBalDKC4+jHgFwr/RyYNj6Pr6V61x2DfL+ EJCnT8nIK0diol/XAn3zkp0CBQHYK32A+lAxwsdw8V0WmgFSaGLh6MeDrKTy+O1YtGQL lRW4ToSimJ7KM73g7/WgJ/lZD0oHxf4tn3qUdGyg4O4aRd94vZCmXlgckCK9wtoEnTIx By1wmnSVOyT/6qltlLMq/NHoH3JbmEp+o19oXoVJJzJxY75DUC/F8bAwXqxVHXMraBwG CNQJwBuxXfuA8b8ReBpbrRr4G875agXduf79V73IbjdTK0GMrf/tPtRPCyES9mwJzUQL 9upw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691796966; x=1692401766; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=uqSttns2QMMHKhEq1iT/6N0civk3/DgixVYj3d7z750=; b=GinBnmCNfhfGJsLQMsbdj8C5iUf8Dk47IEteW+tS8ZXg6f/Xk3I8zpPKa5HTxJDi0h Hcvoz4gdM7ZzdGyvoIK7Eo1H0m/fEMWCcLa4U/5EUSYgSQdviPyFD/LaFtyZk6eZn4Tk MIEVkn6uKF3O6Aw6jVWJhOviDgVjWv4nTWxE3tW8HSfH7YOI+B+d98oEBCBidwl3NmB9 nO2nn31Wupv9F9QIPyOrviGcE86f2e+/p0YLGddxqOhMGkrIKJ1TJyBlqNHyoshbcAo0 ewo6FzvoZgmkAo6Ng7SNGoZm5w50df9lPnQOTFuGHFHjoT5nqXepzUXeaoLPPimVBNzr 4PXw== X-Gm-Message-State: AOJu0Yy0KKq/NMbeHDB2LDzyk8GnXFOWI8tOHUC6eFp290rBFWfh3ftm IxV0rOErr46YwIW18H6mToA0c87wNdl6WDtOVQI= X-Google-Smtp-Source: AGHT+IHmoLAUiv8fk25rU3LsIqT4bGf0NYp3Jdy7r9PrFn7vgSF/A8z6XY7y0W3PdKsPxdaEB7q92Ncr+0mp/5dgQt8= X-Received: from samitolvanen.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:4f92]) (user=samitolvanen job=sendgmr) by 2002:a17:902:da90:b0:1bc:8249:2547 with SMTP id j16-20020a170902da9000b001bc82492547mr1100101plx.12.1691796965861; Fri, 11 Aug 2023 16:36:05 -0700 (PDT) Date: Fri, 11 Aug 2023 23:36:00 +0000 In-Reply-To: <20230811233556.97161-7-samitolvanen@google.com> Mime-Version: 1.0 References: <20230811233556.97161-7-samitolvanen@google.com> X-Developer-Key: i=samitolvanen@google.com; a=openpgp; fpr=35CCFB63B283D6D3AEB783944CB5F6848BBC56EE X-Developer-Signature: v=1; a=openpgp-sha256; l=3217; i=samitolvanen@google.com; h=from:subject; bh=tt28FmYKneUlEuS934Ul5UfwYg3GE/8Wy9t+zpPCYws=; b=owEB7QES/pANAwAKAUy19oSLvFbuAcsmYgBk1sXcZHCAlTnd4EYJhbusgalCGC+w098BuJsGg pjfWx3ysWCJAbMEAAEKAB0WIQQ1zPtjsoPW0663g5RMtfaEi7xW7gUCZNbF3AAKCRBMtfaEi7xW 7vtjC/9aDXQZ1XeqW1KEFEIdmhB56J7RualjvUaGwqw1lObaqRwOTOHqVWWF23giW/63wj+kC2d uHjLduotttcVZkHZsC6bSVritbMUdqcBJPktHpbake9N1DDHjOKuNQV7Nb8/N4fdKLoTbsIhX8J c9wUZRHH+uECCk0s/Vthl8g0IjkG8bxxiTWZPmj9U6cBnZreRQNTMLyS0VAeDbMe1fDLYwCxUOD m7jKpu3cmKHJ0+q07Tw7ImOGqjT+v/47NwVRAfE3wnQ2qG23TXar0JY6Ve/GXc8Cl5iQqIkW8I6 vqNSlOuam4C9fCr1mNVlroRnndKOjNwoqNMGFOpCRRtZboI2i9jEI4sy77bqFyu9Z2AaZODMEky Z8lDTU3yZB+Dfy0y9jrRLlFmdooFQZZqg92id+407SgbATsSpewepWk6+xfbx/2ctL/zCdrzrKE Wqbc1Mw5wnbcu9O9FXMhy5KyHuHKxN0/EpYpF8+0511pfnh6hGOTgck63WxCg0nkRDL/o= X-Mailer: git-send-email 2.41.0.640.ga95def55d0-goog Message-ID: <20230811233556.97161-10-samitolvanen@google.com> Subject: [PATCH 3/5] riscv: Move global pointer loading to a macro From: Sami Tolvanen To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Kees Cook Cc: Guo Ren , Deepak Gupta , Nathan Chancellor , Nick Desaulniers , Fangrui Song , linux-riscv@lists.infradead.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In Clang 17, -fsanitize=3Dshadow-call-stack uses the newly declared platform register gp for storing shadow call stack pointers. As this is obviously incompatible with gp relaxation, in preparation for CONFIG_SHADOW_CALL_STACK support, move global pointer loading to a single macro, which we can cleanly disable when SCS is used instead. Link: https://reviews.llvm.org/rGaa1d2693c256 Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e= 6eeb51f0cb7b8819e50da6d2444d769 Signed-off-by: Sami Tolvanen --- arch/riscv/include/asm/asm.h | 8 ++++++++ arch/riscv/kernel/entry.S | 6 ++---- arch/riscv/kernel/head.S | 15 +++------------ arch/riscv/kernel/suspend_entry.S | 5 +---- 4 files changed, 14 insertions(+), 20 deletions(-) diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h index 13815a7f907a..c53388f784a2 100644 --- a/arch/riscv/include/asm/asm.h +++ b/arch/riscv/include/asm/asm.h @@ -103,6 +103,14 @@ REG_L \dst, 0(\dst) .endm =20 +/* load __global_pointer to gp */ +.macro load_global_pointer +.option push +.option norelax + la gp, __global_pointer$ +.option pop +.endm + /* save all GPs except x1 ~ x5 */ .macro save_from_x6_to_x31 REG_S x6, PT_T1(sp) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 39875f5e08a6..2b4248c6b0a9 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -75,10 +75,8 @@ _save_context: csrw CSR_SCRATCH, x0 =20 /* Load the global pointer */ -.option push -.option norelax - la gp, __global_pointer$ -.option pop + load_global_pointer + move a0, sp /* pt_regs */ la ra, ret_from_exception =20 diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 11c3b94c4534..79b5a863c782 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -110,10 +110,7 @@ relocate_enable_mmu: csrw CSR_TVEC, a0 =20 /* Reload the global pointer */ -.option push -.option norelax - la gp, __global_pointer$ -.option pop + load_global_pointer =20 /* * Switch to kernel page tables. A full fence is necessary in order to @@ -134,10 +131,7 @@ secondary_start_sbi: csrw CSR_IP, zero =20 /* Load the global pointer */ - .option push - .option norelax - la gp, __global_pointer$ - .option pop + load_global_pointer =20 /* * Disable FPU & VECTOR to detect illegal usage of @@ -228,10 +222,7 @@ pmp_done: #endif /* CONFIG_RISCV_M_MODE */ =20 /* Load the global pointer */ -.option push -.option norelax - la gp, __global_pointer$ -.option pop + load_global_pointer =20 /* * Disable FPU & VECTOR to detect illegal usage of diff --git a/arch/riscv/kernel/suspend_entry.S b/arch/riscv/kernel/suspend_= entry.S index 12b52afe09a4..556a4b166d8c 100644 --- a/arch/riscv/kernel/suspend_entry.S +++ b/arch/riscv/kernel/suspend_entry.S @@ -60,10 +60,7 @@ END(__cpu_suspend_enter) =20 ENTRY(__cpu_resume_enter) /* Load the global pointer */ - .option push - .option norelax - la gp, __global_pointer$ - .option pop + load_global_pointer =20 #ifdef CONFIG_MMU /* Save A0 and A1 */ --=20 2.41.0.640.ga95def55d0-goog