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[2620:137:e000::1:20]) by mx.google.com with ESMTP id go30-20020a1709070d9e00b007adc4a0aeb5si240907ejc.873.2022.11.29.19.00.18; Tue, 29 Nov 2022 19:00:42 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@rivosinc-com.20210112.gappssmtp.com header.s=20210112 header.b=zIgXfyOI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229667AbiK3Cfu (ORCPT + 99 others); Tue, 29 Nov 2022 21:35:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229580AbiK3Cfr (ORCPT ); Tue, 29 Nov 2022 21:35:47 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92D7612091 for ; Tue, 29 Nov 2022 18:35:46 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id l22-20020a17090a3f1600b00212fbbcfb78so574227pjc.3 for ; Tue, 29 Nov 2022 18:35:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20210112.gappssmtp.com; s=20210112; h=to:from:cc:content-transfer-encoding:mime-version:message-id:date :subject:from:to:cc:subject:date:message-id:reply-to; bh=cCcorQr3xt7S/9kPkpKfyFY9wnh4zyqAGWy8g0u82Pg=; b=zIgXfyOIwEsoklp4Pj2VNqVlzqwOyXMyUOmtxXL8XX0HZeDXxESlEZt18Ufk8JeuWs 7Q7DrZZk/oBitKWBF64Y72Kp2UZQ7dqDF1tWUk9honYowHZWf7T07fwYEp42FE86aX1Z gotSBlRsn35YWoYFAbebcGNynvUUURc8MWORwvu2WIiMk6mdXfZHEGtdcZ0V537kul+v xAfm8oj9auHJEgnhK834L9M7MGTTIIaw5+ZBB9pNrXTs3FyLHdQzM9t0LKeC8H5zFH92 oL0JH5gN1h6OJbnPfadyReZYXdDjEC1MrmIOqa9EU60CrE7FKP5+UH69dvLJ3D/kKeOV roog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:from:cc:content-transfer-encoding:mime-version:message-id:date :subject:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=cCcorQr3xt7S/9kPkpKfyFY9wnh4zyqAGWy8g0u82Pg=; b=2duwX4HUnFjLcqFQw80wcFePk24Y2rub64xeOyiTHaFC2C/jwVJnaoNOzsEuE9CkO1 brc5Gv9KhPRCij2JiQWm/v3LG0mKtfqY0XD7Si8EdfJjHIcrkcnwYSyCUwVBPz1+tSGr l4wCLctcEJHeMeXbFt8wLEmHW9BLXhXUO84KZ/mEN3lJN9bNbaAvXZXMa6FQ9l6LB5bU GHWNbAVhyI1htge4tNcXGI+GHAv+/ZkjRBtORvTylxoyPK4VWFgX7k9yTmeXLQ3c/I2w iMIjVs++rEHXQwCVd0M6g+s3VjF2aIWcpN5UAjhdEjRKl9Bgi9zo6bEoQQIv/bMZ4hVb BO0Q== X-Gm-Message-State: ANoB5pnvj1mPWAnf8Zoz232d/MX4ZB747wk1zTSj9DPCIbqQu18XfOCo SGYlxOBTD4R4NgiAT4xZnhgzl/7qgcCoQw== X-Received: by 2002:a17:90a:588b:b0:219:c40:e5f with SMTP id j11-20020a17090a588b00b002190c400e5fmr25718858pji.49.1669775746080; Tue, 29 Nov 2022 18:35:46 -0800 (PST) Received: from localhost ([50.221.140.188]) by smtp.gmail.com with ESMTPSA id a10-20020a1709027e4a00b0018912c37c8fsm7638pln.129.2022.11.29.18.35.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Nov 2022 18:35:45 -0800 (PST) Subject: [PATCH 1/2] RISC-V: Align the shadow stack Date: Tue, 29 Nov 2022 18:35:14 -0800 Message-Id: <20221130023515.20217-1-palmer@rivosinc.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Cc: Palmer Dabbelt From: Palmer Dabbelt To: jszhang@kernel.org, guoren@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1750888341825354685?= X-GMAIL-MSGID: =?utf-8?q?1750888341648204828?= The standard RISC-V ABIs all require 16-byte stack alignment. We're only calling that one function on the shadow stack so I doubt it'd result in a real issue, but might as well keep this lined up. Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") Signed-off-by: Palmer Dabbelt Reviewed-by: Jisheng Zhang --- arch/riscv/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index be54ccea8c47..acdfcacd7e57 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -206,7 +206,7 @@ static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], * shadow stack, handled_ kernel_ stack_ overflow(in kernel/entry.S) is used * to get per-cpu overflow stack(get_overflow_stack). */ -long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)]; +long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)] __aligned(16); asmlinkage unsigned long get_overflow_stack(void) { return (unsigned long)this_cpu_ptr(overflow_stack) + From patchwork Wed Nov 30 02:35:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Palmer Dabbelt X-Patchwork-Id: 27569 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp694510wrr; Tue, 29 Nov 2022 18:52:16 -0800 (PST) X-Google-Smtp-Source: AA0mqf78u+v8YqQiLNgYCtdgq0W6lqVnGyPjHrWNJEJvcsbocTW5MUxe18qMqG/NYFn7yj71EyOz X-Received: by 2002:a17:902:ab8d:b0:187:1e83:2505 with SMTP id f13-20020a170902ab8d00b001871e832505mr44519037plr.132.1669776736455; Tue, 29 Nov 2022 18:52:16 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1669776736; cv=none; d=google.com; s=arc-20160816; b=KYUrUPVUCPcZjaOsDKrLqhXytaYVUp9AyP/DRmV/CDzHJyzf1YyWzSXAqNpfPCvi7I 2dpA9Ozg8ef0qJESv2ZmFQOB/Sjywo0aD1HXnINVjICturYtVBYcWTF84+OGfghX5opM I8Cd2cUvazZysG2WvkTcdL2rbdkN6jyBmGT17hjAa3DPjM8SXCOOzbkinf9W4YhmhvDw dA7vmrRs4XBWrwgpQvG94hVM2KdSwEwK8nTqlnI1LFISSJdgy42WFTKH2fe9ppycK9i/ tNL0HKa/3ttv+uQaWyMNa1UiDkpuWLPFL/WwHQ5Imlm8/Gc3SfDQUbIxz0lQTfAAzdkC sGTA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:to:from:cc:content-transfer-encoding :mime-version:references:in-reply-to:message-id:date:subject :dkim-signature; bh=WK41owb8xQar3YPAMlOv6Q9IlVxICe86b2kCZ83CjmI=; b=YwD6ZS5gHnnHtZoE6SgFfwGx0X/fQjVeqpMyvkccNPYd8sWiSZQ0gchcwQy7rzXGr9 8hOfYy6651GQHE+IazBP7g4piuml/NZMkPRPPMc6afSCTN89ij2E/UaBxVGIafzoBqbh A35exlY89Wtq9NM5qDV+uhXYdLeGX25uzEsLsySg37/OAN4d+DDPadfmH3Ks3U1KRkiP FjGkdZVpaoozxmtEWl57dcIQywoKT3/irdjiRQ8DRvQFNITkEcYFfzEk5BTdN/VHd+hr JOCifK4ok+bsXqFmYFI/P7bH4OC180WbXXNWBL7xPIVQ+DaVVmGtB/9Fo/nsQGlF8y7F cJeQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@rivosinc-com.20210112.gappssmtp.com header.s=20210112 header.b=NYaY1njF; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. 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Signed-off-by: Palmer Dabbelt Reviewed-by: Guo Ren Reviewed-by: Jisheng Zhang --- arch/riscv/kernel/traps.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index acdfcacd7e57..336d4aadadb1 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -200,18 +200,18 @@ void __init trap_init(void) } #ifdef CONFIG_VMAP_STACK +/* + * Extra stack space that allows us to provide panic messages when the kernel + * has overflowed its stack. + */ static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)__aligned(16); /* - * shadow stack, handled_ kernel_ stack_ overflow(in kernel/entry.S) is used - * to get per-cpu overflow stack(get_overflow_stack). + * A temporary stack for use by handle_kernel_stack_overflow. This is used so + * we can call into C code to get the per-hart overflow stack. Usage of this + * stack must be protected by spin_shadow_stack. */ long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)] __aligned(16); -asmlinkage unsigned long get_overflow_stack(void) -{ - return (unsigned long)this_cpu_ptr(overflow_stack) + - OVERFLOW_STACK_SIZE; -} /* * A pseudo spinlock to protect the shadow stack from being used by multiple @@ -222,6 +222,12 @@ asmlinkage unsigned long get_overflow_stack(void) */ unsigned long spin_shadow_stack; +asmlinkage unsigned long get_overflow_stack(void) +{ + return (unsigned long)this_cpu_ptr(overflow_stack) + + OVERFLOW_STACK_SIZE; +} + asmlinkage void handle_bad_stack(struct pt_regs *regs) { unsigned long tsk_stk = (unsigned long)current->stack;