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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT 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 3F1C1C433E0 for ; Tue, 19 Jan 2021 22:12:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 155CE230FE for ; Tue, 19 Jan 2021 22:12:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728993AbhASWMw (ORCPT ); Tue, 19 Jan 2021 17:12:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729771AbhASWIw (ORCPT ); Tue, 19 Jan 2021 17:08:52 -0500 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E24FC061575 for ; Tue, 19 Jan 2021 14:08:12 -0800 (PST) Received: by mail-pg1-x52b.google.com with SMTP id v19so13815010pgj.12 for ; Tue, 19 Jan 2021 14:08:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ELInWqxXJUdZABjVVRG764v9dascUS8CB4mjpW3H2yQ=; b=ab3oLJzIFTZQrdfLW+gTqruevNzRZlrqWK3e1HaKR0QYO8WX62/zQn5jjdoVjYBVzH THgMZi02TV4AWIP17lMi7ukSiiBC1MkCOBDLd5cVnIfUsGL5nzaSgTOOFAcp6+NiYju+ lApCH07+GR9TCBZVjJgGcpwEyoKhC4pxpAJaNsG+PluEuRsibalfE6pX+sWyuMo29gIK eszAB4BYOG8K64pgoa0o8aBM7SV2Yf3PqIIKVFLk7kZ45k0wdQHClS2awoVOyBpK33hb sBaVTO2TMW5xXX1aSjHs7he5HAxVXoBp9dSEdIcXZz3LcupGcOGB0bgskADMw7BEzv0n 1ZtQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ELInWqxXJUdZABjVVRG764v9dascUS8CB4mjpW3H2yQ=; b=MCuQY/1EHokw/wLkFa5t0MC4xKHvaRmQQQwh0TRaaus9cuDQpbMuadtV4sL2MLtEVs WGaSNgSeZpLs1LymWWcD0My24E73Q4uv4f8/iPa1A9E91gYBWQNTLbvA7JO3us+T9nFr emCSbdZmF+ya4dx8fm1xtwqnfSuipUYcNP1aYC/rF900NUFsC37cpBv28tbidCrnmWPO G+y0/NfatDLx8nFh5NsQo2VkzCI+zCgN3bbKsdQiea0B2BR991104voyfdVOmeeDUJfy hxveU5+qKwbvY2tQqU67tWAmaHspnQmRG8chFfwDcp13F8x7awHB+zuyD/WhaOKcXyAz HYPw== X-Gm-Message-State: AOAM531YY6dcMU9ub73s1w8XpXukWGbAbLshv+6RhSOH1Fo6TvbCw7Hn 3JT5KrT9Zfqp0vgnJe/cczM= X-Google-Smtp-Source: ABdhPJwMxHwLKsiFlrwFkAwTdrgj+xxDw6GTXrxIh1XyAdCu+t7BUYe9op17/6WO+e6CKmI23S/NZQ== X-Received: by 2002:a63:8249:: with SMTP id w70mr6347924pgd.138.1611094092092; Tue, 19 Jan 2021 14:08:12 -0800 (PST) Received: from laptop.hsd1.wa.comcast.net ([2601:600:9b7f:872e:a655:30fb:7373:c762]) by smtp.gmail.com with ESMTPSA id 72sm95196pfw.170.2021.01.19.14.08.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Jan 2021 14:08:11 -0800 (PST) From: Andrei Vagin To: Will Deacon , Catalin Marinas Cc: Oleg Nesterov , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Andrei Vagin Subject: [PATCH 0/3] arm64/ptrace: allow to get all registers on syscall traps Date: Tue, 19 Jan 2021 14:06:34 -0800 Message-Id: <20210119220637.494476-1-avagin@gmail.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Right now, ip/r12 for AArch32 and x7 for AArch64 is used to indicate whether or not the stop has been signalled from syscall entry or syscall exit. This means that: - Any writes by the tracer to this register during the stop are ignored/discarded. - The actual value of the register is not available during the stop, so the tracer cannot save it and restore it later. This series introduces NT_ARM_PRSTATUS to get all registers and makes it possible to change ip/r12 and x7 registers when tracee is stopped in syscall traps. For applications like the user-mode Linux or gVisor, it is critical to have access to the full set of registers in any moment. For example, they need to change values of all registers to emulate rt_sigreturn and they need to have the full set of registers to build a signal frame. Andrei Vagin (3): arm64/ptrace: don't clobber task registers on syscall entry/exit traps arm64/ptrace: introduce NT_ARM_PRSTATUS to get a full set of registers selftest/arm64/ptrace: add a test for NT_ARM_PRSTATUS arch/arm64/include/asm/ptrace.h | 5 + arch/arm64/kernel/ptrace.c | 130 +++++++++++----- include/uapi/linux/elf.h | 1 + tools/testing/selftests/arm64/Makefile | 2 +- tools/testing/selftests/arm64/ptrace/Makefile | 6 + .../arm64/ptrace/ptrace_syscall_regs_test.c | 142 ++++++++++++++++++ 6 files changed, 246 insertions(+), 40 deletions(-) create mode 100644 tools/testing/selftests/arm64/ptrace/Makefile create mode 100644 tools/testing/selftests/arm64/ptrace/ptrace_syscall_regs_test.c -- 2.29.2