From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B02FFC433E4 for ; Fri, 14 Aug 2020 17:28:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 600A820855 for ; Fri, 14 Aug 2020 17:28:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="J0yRjS8w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 600A820855 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C5B846B002F; Fri, 14 Aug 2020 13:28:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C0DA46B0030; Fri, 14 Aug 2020 13:28:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD26F6B0031; Fri, 14 Aug 2020 13:28:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0167.hostedemail.com [216.40.44.167]) by kanga.kvack.org (Postfix) with ESMTP id 73D346B002F for ; Fri, 14 Aug 2020 13:28:15 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 379D982499A8 for ; Fri, 14 Aug 2020 17:28:15 +0000 (UTC) X-FDA: 77149857750.01.flag01_5d0498a26ffe Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin01.hostedemail.com (Postfix) with ESMTP id 10FE21004C6C4 for ; Fri, 14 Aug 2020 17:28:15 +0000 (UTC) X-HE-Tag: flag01_5d0498a26ffe X-Filterd-Recvd-Size: 6629 Received: from mail-qk1-f201.google.com (mail-qk1-f201.google.com [209.85.222.201]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Fri, 14 Aug 2020 17:28:14 +0000 (UTC) Received: by mail-qk1-f201.google.com with SMTP id a130so6517404qkg.9 for ; Fri, 14 Aug 2020 10:28:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=E0RrGh1M0jqaaDoEOkU8MvQi4g07cx9su4pS9IT1SWw=; b=J0yRjS8wAi98SLl40BtGkKwGJXb87bHWptPKQUee0Z7i8RnowmsAsnTsSSGI/mRVKG /jBE+O/OM0IlfTDa5WKWGDVszoGwgZAxqhir2+UYOvzVv0T0kxYGs89EIVE3j7zvDcQP GPQ1zisFX3ghoL4cEwaGUe+RAIqE8fE978O2GWSaMwrA6JP4uyHCDH6oudvPU+qzrFnK s/DztyfYwRhXAGuuuDUHlU5qU/ik0sNsoQCOVLC2aU7SaX6rXyrlmEfq6jLz9760Mo/W YzyxoAF7tuNY/jCOHcxGNwqQSk8KoNiASEdIQr3iycLeHaTqYkXL/Uqo8uXoj1mabJku 9Q2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=E0RrGh1M0jqaaDoEOkU8MvQi4g07cx9su4pS9IT1SWw=; b=HPngFzniV1oW7NQHp6fkOWOH2D2fvcaONPYNuqVaohNYdlVXHqiWDkgOSNQL8M8AGl 8uiNOyXJlDZYAQpR/By0SRd2+4J/bsXCkcOlrTC5bN+3nsoRW71Gsp4hTNYOTk+344lv OsHwI4Dc4gsHl126RAPEjZbTMwiNVopSN6R7oMOKrOO1Z1XoiMp0K5w2v37h6ISOFZqU IfE6BXPRWjFNi/jnpLeKdj8xx1jOSsbXCN+e6XSEcSwAgokr2Pmk19VSkBDqNoEpl9hg DUAWdYdPaLbb2atDiEQ7udkg6pbqNrSEji3Jw11r/8XjZ5O02aSUKnV4ZQ0V0z1/l3w6 /5qQ== X-Gm-Message-State: AOAM531m+kx2yOPS0oVne6mzY+VTAu3mn7vvez3HJjoPuWaSOEWOxd1J cDIu2/4s6XLCGZYm+jvqJS/mLo7Noh6VkflZ X-Google-Smtp-Source: ABdhPJy3SdR9WMFOSxqndhovcLxyBqUrrg3mnD1AcV1Kt+RAUKx381UmFBB5e6t6uAgctFxBWyRwguDJG3EOOPOZ X-Received: by 2002:a0c:9a0c:: with SMTP id p12mr3610073qvd.75.1597426093874; Fri, 14 Aug 2020 10:28:13 -0700 (PDT) Date: Fri, 14 Aug 2020 19:27:03 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.28.0.220.ged08abb693-goog Subject: [PATCH 21/35] arm64: mte: Add in-kernel tag fault handler From: Andrey Konovalov To: Dmitry Vyukov , Vincenzo Frascino , Catalin Marinas , kasan-dev@googlegroups.com Cc: Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 10FE21004C6C4 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Vincenzo Frascino Add the implementation of the in-kernel fault handler. When a tag fault happens on a kernel address: * a warning is logged, * the faulting instruction is skipped, * the execution continues. When a tag fault happens on a user address: * the kernel executes do_bad_area() and panics. Signed-off-by: Vincenzo Frascino Co-developed-by: Andrey Konovalov Signed-off-by: Andrey Konovalov --- arch/arm64/mm/fault.c | 50 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 5e832b3387f1..c62c8ba85c0e 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -222,6 +223,20 @@ int ptep_set_access_flags(struct vm_area_struct *vma, return 1; } +static bool is_el1_mte_sync_tag_check_fault(unsigned int esr) +{ + unsigned int ec = ESR_ELx_EC(esr); + unsigned int fsc = esr & ESR_ELx_FSC; + + if (ec != ESR_ELx_EC_DABT_CUR) + return false; + + if (fsc == ESR_ELx_FSC_MTE) + return true; + + return false; +} + static bool is_el1_instruction_abort(unsigned int esr) { return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR; @@ -294,6 +309,18 @@ static void die_kernel_fault(const char *msg, unsigned long addr, do_exit(SIGKILL); } +static void report_tag_fault(unsigned long addr, unsigned int esr, + struct pt_regs *regs) +{ + bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0; + + pr_alert("Memory Tagging Extension Fault in %pS\n", (void *)regs->pc); + pr_alert(" %s at address %lx\n", is_write ? "Write" : "Read", addr); + pr_alert(" Pointer tag: [%02x], memory tag: [%02x]\n", + mte_get_ptr_tag(addr), + mte_get_mem_tag((void *)addr)); +} + static void __do_kernel_fault(unsigned long addr, unsigned int esr, struct pt_regs *regs) { @@ -317,12 +344,16 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr, msg = "execute from non-executable memory"; else msg = "read from unreadable memory"; + } else if (is_el1_mte_sync_tag_check_fault(esr)) { + report_tag_fault(addr, esr, regs); + msg = "memory tagging extension fault"; } else if (addr < PAGE_SIZE) { msg = "NULL pointer dereference"; } else { msg = "paging request"; } + die_kernel_fault(msg, addr, esr, regs); } @@ -658,10 +689,27 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) return 0; } +static int do_tag_recovery(unsigned long addr, unsigned int esr, + struct pt_regs *regs) +{ + report_tag_fault(addr, esr, regs); + + /* Skip over the faulting instruction and continue: */ + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); + + return 0; +} + + static int do_tag_check_fault(unsigned long addr, unsigned int esr, struct pt_regs *regs) { - do_bad_area(addr, esr, regs); + /* The tag check fault (TCF) is per TTBR */ + if (is_ttbr0_addr(addr)) + do_bad_area(addr, esr, regs); + else + do_tag_recovery(addr, esr, regs); + return 0; } -- 2.28.0.220.ged08abb693-goog