From nobody Fri Dec 19 14:38:20 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 41EE6C83F15 for ; Mon, 28 Aug 2023 19:59:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233567AbjH1T7Y (ORCPT ); Mon, 28 Aug 2023 15:59:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233540AbjH1T6q (ORCPT ); Mon, 28 Aug 2023 15:58:46 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91DE1189 for ; Mon, 28 Aug 2023 12:58:44 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-d74a012e6a6so4432254276.2 for ; Mon, 28 Aug 2023 12:58:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1693252724; x=1693857524; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=GN6X1nlK+F0kjkEC50FG9os31FAuUCJYmCM49+1obnI=; b=q81rXqLshiF0sln/xS3h/1Wt74xT2Rdg2j7FkroNKWNJx+s5YHbY+oxX80kCoOEdXg Z7tbUBEmnha1x55o337Yu6Lp+PK9LnYIpjNDnXpf7Vvob1fBYdUFHdVNRYzgfh16aSLv eFNKGP5rRTkOAMSM3mrjAPNqs5knGLIBbNRZAC6qGU+CNi/lzLXAiQhO62xa0d/tNvJ+ HZQCnftScs5HC5H/QHtUIo0uBGDaDIJXYW2D2SPFvrSpGGn81MfWM1OEFhJRudgn2+le WexQrz+RIoMq4d/FZyHuGt5KMF8ZH4GobjeJX5y+t0Ma6T4e2S48xP0NJhR5CYYZChPH OKqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693252724; x=1693857524; 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=GN6X1nlK+F0kjkEC50FG9os31FAuUCJYmCM49+1obnI=; b=GEyoWvVVKpe4fVkd5Y7FcmKYnxaOtIH8wdoTXyG/jv2Xd1KrgzEUE+nKWalR/iD1dJ W5574ZI+82dE4zwi63/3iybRDQQTakPd1GcO/xYCUu+p0KHgfuEFW8+5HnpCDqZ8JTJU QQwecIwGFzOWTB/8dKZJ5ZtI4Wdzp4hL87VZetRtEtjHe8HfXczOcWrLvJ2Mfe+0F0Qp 6h05ZcUb/MHU7nPAEjWdB5LeTvuTI1e4vQwzCYGHY2LnBcosQ/g9LoaMMIsppzpmid49 0c/JKYWo6G+afVlFIyBo4hahU3vD86L2bT5ho884eVHBuEJnGq18fy303HcbYT75Emli oSIg== X-Gm-Message-State: AOJu0YzhnvWgasedoyqBOHHsBQdyL+es3z61JRGSxBzBDFYdYvgCQzYF i4BCbiW6JeavF90x1CpP/yF729b+0lcwpheSi70= X-Google-Smtp-Source: AGHT+IH/uHwJj6+qOeylfRyEPqpB+nnMtItRxR7gf+ULc0gWYu3yZPJVS4kkyblR9fUvFWo2HvJU3EuGasR5rTd2B1w= X-Received: from samitolvanen.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:4f92]) (user=samitolvanen job=sendgmr) by 2002:a25:9011:0:b0:d5d:b03c:49b2 with SMTP id s17-20020a259011000000b00d5db03c49b2mr820198ybl.11.1693252723904; Mon, 28 Aug 2023 12:58:43 -0700 (PDT) Date: Mon, 28 Aug 2023 19:58:37 +0000 In-Reply-To: <20230828195833.756747-8-samitolvanen@google.com> Mime-Version: 1.0 References: <20230828195833.756747-8-samitolvanen@google.com> X-Developer-Key: i=samitolvanen@google.com; a=openpgp; fpr=35CCFB63B283D6D3AEB783944CB5F6848BBC56EE X-Developer-Signature: v=1; a=openpgp-sha256; l=3271; i=samitolvanen@google.com; h=from:subject; bh=Chgku5okNNw1TPF+7h/tJxx5VnEIks6hZ2ypKsZTKYg=; b=owEB7QES/pANAwAKAUy19oSLvFbuAcsmYgBk7PxqRbtkifAND8x/XfLzfQWcnICH3txr02qPt 4eiKf2aYjSJAbMEAAEKAB0WIQQ1zPtjsoPW0663g5RMtfaEi7xW7gUCZOz8agAKCRBMtfaEi7xW 7sqPC/4yfD8F4LJhON/0j9LDQmdASW7omk5GP9QTz9u9V2kMfasvvS5/J6shUYxruhqnrbLQBUp oZG+GjK1FZXYmm2NhWg4FLwoGp73evhYqS3wI+Ft3xabSmr5Na3lU51SZXDGqV8uyQ7euwUibuM 1IB+PWku6qCOxTHa+PmjyOlXV/KauzFtIzwmz+0x5d45qcRehgOD29B8x93CCG4ocGo16RTP8LI F/iGt9KvESUFJHI8k0VjTovZNvf6YxjaSUpyeHxe3VVQSccGWV/T3h55eOORae0j0Myri46bWi6 G6OIOjCjM5wvPYvwQTVyYFnbv5wTS0DJqhUWZt3ZEVviB/dFtXNBfxwtPWVuNItQMaZQ/8iaxqH ZZt1G2FWe/DvsQ5lHk95L6xpiDHTU8W8m68q4rh/0qju4f8K6jxJcN6sSbo2s98UyF1YVfErhSD UX5opXBgLT/rq9utajC5hslrYEgFPNP1pUHjVWRg8zD8f17xYD7/57e0gz+NISpgLceIs= X-Mailer: git-send-email 2.42.0.rc2.253.gd59a3bf2b4-goog Message-ID: <20230828195833.756747-11-samitolvanen@google.com> Subject: [PATCH v3 3/6] riscv: Move global pointer loading to a macro From: Sami Tolvanen To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Kees Cook Cc: Clement Leger , 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 Tested-by: Nathan Chancellor --- 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 a306562636e4..6215dcf2e83b 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 2.42.0.rc2.253.gd59a3bf2b4-goog