From nobody Thu Dec 18 07:58:12 2025 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 0AAA1C001E0 for ; Tue, 15 Aug 2023 20:35:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238147AbjHOUfL (ORCPT ); Tue, 15 Aug 2023 16:35:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238052AbjHOUey (ORCPT ); Tue, 15 Aug 2023 16:34:54 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12174F7 for ; Tue, 15 Aug 2023 13:34:53 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id 98e67ed59e1d1-26943ac3fa2so3126567a91.3 for ; Tue, 15 Aug 2023 13:34:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692131692; x=1692736492; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=BfDLHnMbXQceNrVQLGjVUevqJ2xwYxenmhNK/tAF/sk=; b=DveYx2ypgHekd9E3zy9CT1ilJONYIrAnPqHRj9ZtXg944Rf0TWVVNG5jaFobMnoKx0 Qp6jSJbrWh3E2/h9IXPRd2IM3jaJArvh4oKLp7/khzJJ/4YoiwEv/DKqr19Ru89mBaYv 1gt7hiExW5s9lLZMvCZRWPyrP/GDG1LqMTngfLcIolNUd8lCABgY4ON75DRwtNUOCk8B JY5g55OHAze9zUBVPQ+rocjrZ/v9jCkE6obEf+/vP5i9YGYK/d6QF7IAgDOSXS1kHXVD FeNp6SoviL3M8abvX30FCaMuBBgTkMnTrZyfZofD7Pl87xvQwDtW7fNUw3gGmTWAH0AY dFmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692131692; x=1692736492; 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=BfDLHnMbXQceNrVQLGjVUevqJ2xwYxenmhNK/tAF/sk=; b=aMfUpnTHb1+bprpIr3JiJbmyfz3QYXAvNWgnQ3qQK62kdZrWVIb2bVGzqP0sxOlZJ9 oN+W+Uonuee5RQqbSQMFB8/s33IkUANttF8IrNofQILXRRp1NXrPGH4gKyuIVhY8eOZY wPGbaupu5T9BrfJOTyQpqD00UYyc6l8dbjQhLl1ez9Y328Tumi7K2EsyXXJAmTqJ6Vps WXz06Qtwlt3feJkFPB8m4rL8fj4CWk7RCGkwlkv/f5IEaJCJwZpE2ZuCiHh4ZpSNC9Bb 6XubJg6gzsKFsUXV7zLqVUBRqrI4bpXk1m9aa5GFM3oBlWBhEbjIW4Pvjw51zoRDblOK YDeg== X-Gm-Message-State: AOJu0Yw7WBw/e0OwhDsXIh5NntaI78iyb+d/RPcjoZAtlFhKWhDYQPE7 +IDkmDIzROJLcr7si6O70csJ1IXqWKbcWQXa5kE= X-Google-Smtp-Source: AGHT+IG4n+M3PSO3DhS/2Scpx+tUwpXnKVdLJNTSN6YSIUZ+vrp2chjur8+avcRYM+CJmcVopciJDOywc23KOj4HoFo= X-Received: from samitolvanen.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:4f92]) (user=samitolvanen job=sendgmr) by 2002:a17:90b:4393:b0:263:3437:a0b0 with SMTP id in19-20020a17090b439300b002633437a0b0mr3063684pjb.3.1692131692589; Tue, 15 Aug 2023 13:34:52 -0700 (PDT) Date: Tue, 15 Aug 2023 20:34:46 +0000 In-Reply-To: <20230815203442.1608773-8-samitolvanen@google.com> Mime-Version: 1.0 References: <20230815203442.1608773-8-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=5ixoDk+W6BxwBv4tIu2eVSrOr56ebYlcn47cfqFXXgA=; b=owEB7QES/pANAwAKAUy19oSLvFbuAcsmYgBk2+FiHUFljIaux+9IC+0XLbF6reJW5Y5V3fbd/ /MD1Qt4OqyJAbMEAAEKAB0WIQQ1zPtjsoPW0663g5RMtfaEi7xW7gUCZNvhYgAKCRBMtfaEi7xW 7kdQDACYUsshok1LuWlv5stJjrwH99NJQrdDSX0WI0YLs+JulAYvsnIPJAatZgneQWhTPWBynMO rJ3Ix+mbOgesN6Los5e0Z5iR+60FzUznS4csogCnjAI1+8EEVryA7ygmOnVm4/wnNpslAOjORp7 byQ+dXEu0N175Wnuc3vqbRnwlcaSIgJR+3bGVEuk8ezzcuTN42WVem7P7gBBgGWi+MzsEtJk9IA +oCPRG0zWkpcBkqHS77+B58Wg9Z/YAaYEeyeqUKq1AMU2MIUP1ul8YRN6CX93320mx9vMOO6tff vPHHw66ck3QzRW5YPmT1EYusoHAeXpCxw6RBC7i2r5Wyqw/QVNOqtKvrkJuzNmMRFJnl9zlGZbs C0IN9uG9VSOuYRky9JDPhBidXrnk7bvsMGzrNuj703Iz9WVkn+LfAUI+Nn/LiYYHYOqhR9w+PRl ERHb8HUO9XJqfcJPtffC4okUlO3NCdKwN6FcN6izZWDFGeuHyBokuvxqemECQWRpFEqkM= X-Mailer: git-send-email 2.41.0.694.ge786442a9b-goog Message-ID: <20230815203442.1608773-11-samitolvanen@google.com> Subject: [PATCH v2 3/6] 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 8e446be2d57c..f34dd1a526a1 100644 --- a/arch/riscv/include/asm/asm.h +++ b/arch/riscv/include/asm/asm.h @@ -109,6 +109,14 @@ 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 2.41.0.694.ge786442a9b-goog