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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 C3969C432BE for ; Thu, 26 Aug 2021 09:29:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A991610C7 for ; Thu, 26 Aug 2021 09:29:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241022AbhHZJa2 (ORCPT ); Thu, 26 Aug 2021 05:30:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233249AbhHZJaS (ORCPT ); Thu, 26 Aug 2021 05:30:18 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D1DBC061757 for ; Thu, 26 Aug 2021 02:29:29 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id m6-20020ac807c6000000b0029994381c5fso1404996qth.5 for ; Thu, 26 Aug 2021 02:29:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=EYQCvWaSOAoZfGoi/+7YMUDNib2TjNJAY1W234CWDnA=; b=rYQm+h3uOmjt8Qq8qEwiUduzIY8eHzycw8u3wdyV+FmaNn9HCZxhN5Vu2jTQeAXDtI FSe/cyVR5PmCG5N5PQ9d1CZlxi4AVFtSunOifs/dpNvOO1rq+xySsaI5BPX604itMgwY DLiDD9G209a/PAjTOqtY5NbnrkSUZRg65uHN14ttUGa5lotlaY0T6NsLLuVQH7MW09JW q4O8LaMQ9PI8AB90D5j081qhbMNgieWXNoBuGYBPMlhxELjmJbR8KYRpteA5hANi8f8f gouK3+gcd3yUvPvdu0U8AiWpZ4wwofFksRZuiEEyy8i+Shq35akBOK6cxXInARsMQbT+ FdVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=EYQCvWaSOAoZfGoi/+7YMUDNib2TjNJAY1W234CWDnA=; b=L4jgKLosn1+JlOPI4kShf5LsGRMJXEse2imG89dXv6lGopWzZ9umltENhQp2feq7O4 E4iQtOUvKmAUAENS2fPlhenqu9XdoDiysrO2FYIelSbhhvPyAwWgVUefpVfJGjjKzgdG VXDBAGtZH1ZPgDinBUyI+lS1Ku78HC+jZnrw6jJBeBTTYuCp/9SNDBHoobycGhxOFMkZ nO92N4Gy9S9KV49+TGguRnsovdOis0iFuvQ5W/smET794pTiVvPNFgCSWSaYtNgJF1XX aUKCwHfuW7bNq4htYD9Fslbqrmj71aELQLf6RuIACEWhe6tP1d0wxWeCAjel2O3XLE2w 00nQ== X-Gm-Message-State: AOAM532Cj2NHPzHOhZAybmvo57XI/nIo02bb0fYSLz6UJhlcXC5/BmP6 dtid00hxoUzQLMyQXH7VfvzrT38xC0rzSw== X-Google-Smtp-Source: ABdhPJwk9Nz9+Ki7HD7mEP9RBjDA9+hL9ifFnr6I0W+Sk0NqibIGohMPAM6P1mlDX6oQ1bGQr7VFPEJVYdMw0g== X-Received: from woodylin.ntc.corp.google.com ([2401:fa00:fc:202:63b:ba74:2193:40c]) (user=woodylin job=sendgmr) by 2002:a05:6214:5094:: with SMTP id kk20mr3099143qvb.3.1629970168601; Thu, 26 Aug 2021 02:29:28 -0700 (PDT) Date: Thu, 26 Aug 2021 17:28:54 +0800 Message-Id: <20210826092854.58694-1-woodylin@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.33.0.rc2.250.ged5fa647cd-goog Subject: [PATCH] ANDROID: staging: add userpanic-dev driver From: Woody Lin To: Greg Kroah-Hartman , Todd Kjos Cc: "=?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?=" , Martijn Coenen , Joel Fernandes , Christian Brauner , Hridya Valsaraju , Suren Baghdasaryan , linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev, Woody Lin Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add char device driver 'userpanic-dev' that exposes an interface to userspace processes to request a system panic with customized panic message. Signed-off-by: Woody Lin --- drivers/staging/android/Kconfig | 12 +++ drivers/staging/android/Makefile | 1 + drivers/staging/android/userpanic-dev.c | 110 ++++++++++++++++++++++++ 3 files changed, 123 insertions(+) create mode 100644 drivers/staging/android/userpanic-dev.c diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig index 70498adb1575..b1968a1ee821 100644 --- a/drivers/staging/android/Kconfig +++ b/drivers/staging/android/Kconfig @@ -14,6 +14,18 @@ config ASHMEM It is, in theory, a good memory allocator for low-memory devices, because it can discard shared memory units when under memory pressure. +config USERPANIC_CHARDEV + bool "User-panic device interface" + help + Say Y here to use user-panic device for user space processes to + request a system panic with customized panic message. + + A char device '/dev/userspace_panic' is created by this driver + when selecting 'Y'. User processes can request panic and attach + customized panic message and title by ioctl(CRASH_INFO). Later any + panic handler can collect the panic message to build debugging + reports. + endif # if ANDROID endmenu diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile index e9a55a5e6529..851efb3435ac 100644 --- a/drivers/staging/android/Makefile +++ b/drivers/staging/android/Makefile @@ -2,3 +2,4 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_ASHMEM) += ashmem.o +obj-$(CONFIG_USERPANIC_CHARDEV) += userpanic-dev.o diff --git a/drivers/staging/android/userpanic-dev.c b/drivers/staging/android/userpanic-dev.c new file mode 100644 index 000000000000..b9a0f0c01826 --- /dev/null +++ b/drivers/staging/android/userpanic-dev.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* userpanic-dev.c + * + * User-panic Device Interface + * + * Copyright 2021 Google LLC + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ + +#include +#include +#include +#include + +struct userpanic_crash_info { + void __user *title_uaddr; + void __user *msg_uaddr; +}; + +#define CRASH_INFO (_IOW('U', 179, struct userpanic_crash_info)) + +static int do_userpanic(const char *title, const char *msg) +{ + const size_t msgbuf_sz = PAGE_SIZE; + char *msgbuf; + + msgbuf = kmalloc(msgbuf_sz, GFP_KERNEL); + if (!msgbuf) + return -ENOMEM; + + pr_emerg("User process '%.*s' %d requesting kernel panic\n", + sizeof(current->comm), current->comm, current->pid); + if (msg) + pr_emerg(" with message: %s\n", msg); + + /* Request panic with customized panic title. */ + snprintf(msgbuf, msgbuf_sz, "U: %s: %s", current->comm, title); + panic(msgbuf); + kfree(msgbuf); + return -EFAULT; +} + +static long userpanic_device_ioctl(struct file *file, u_int cmd, u_long arg) +{ + struct userpanic_crash_info crash_info; + char *title; + char *msg = NULL; + int ret; + + switch (cmd) { + case CRASH_INFO: + if (copy_from_user(&crash_info, (void __user *)arg, sizeof(crash_info))) + return -EFAULT; + + if (!crash_info.title_uaddr) + return -EINVAL; + + title = strndup_user(crash_info.title_uaddr, PAGE_SIZE); + if (IS_ERR(title)) { + pr_err("failed to strndup .title_uaddr: %d\n", PTR_ERR(title)); + return -EINVAL; + } + + if (crash_info.msg_uaddr) { + msg = strndup_user(crash_info.msg_uaddr, PAGE_SIZE); + if (IS_ERR(msg)) { + kfree(title); + pr_err("failed to strndup .msg_uaddr: %d\n", PTR_ERR(msg)); + return -EINVAL; + } + } + + ret = do_userpanic(title, msg); + kfree(msg); + kfree(title); + return ret; + } + + return -EINVAL; +} + +static const struct file_operations userpanic_device_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = userpanic_device_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +static struct miscdevice userpanic_device = { + .minor = MISC_DYNAMIC_MINOR, + .name = "userspace_panic", + .fops = &userpanic_device_fops, +}; + +static int __init userspace_panic_dev_init(void) +{ + int ret; + + ret = misc_register(&userpanic_device); + if (ret) + pr_err("misc_register failed for userspace_panic device\n"); + + return ret; +} + +device_initcall(userspace_panic_dev_init); + +MODULE_DESCRIPTION("User-panic interface device driver"); +MODULE_AUTHOR("Woody Lin "); +MODULE_LICENSE("GPL v2"); -- 2.33.0.rc2.250.ged5fa647cd-goog