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=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 E09C3C4321E for ; Fri, 7 Sep 2018 13:38:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AE6F2086B for ; Fri, 7 Sep 2018 13:38:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="UzJqB5uI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9AE6F2086B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=android.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729407AbeIGSTu (ORCPT ); Fri, 7 Sep 2018 14:19:50 -0400 Received: from mail-ed1-f67.google.com ([209.85.208.67]:38826 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728206AbeIGSTt (ORCPT ); Fri, 7 Sep 2018 14:19:49 -0400 Received: by mail-ed1-f67.google.com with SMTP id h33-v6so11552122edb.5 for ; Fri, 07 Sep 2018 06:38:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=android.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=r3a/c2oMd9v69Zdf5hDPreXO2X9N0YgX5307ChuDaW4=; b=UzJqB5uIdvu+5i4Ph4/XNi279/jcckDIEKe3r4Nulprmdz0haRAKMz3+7qLcFBxBOe vajQ0eugDo2VBs2vCMG0Q/vjv76a25o9Yh5+isOeQm9eHsbJ6huwJXp2bGM3g+Vx1YXx 4OOuOQeiPGY6YWBQO5UVVTzXfQO7qmQxRVuCYhVKrShdyb0PgAtfa8j7YzNt5BEBVLPH cjgCd62n7XO/Sh4Z78qod4nKQHJ+WAvbgGXuqsFcVaD9c39vQxSGd/aUUyaacGWDW07C LBIy4P9JiD50VQPxU+RT+z9aSg+TqjbhqPornH2vw1XjPEB1lu+SfaCgNH0UYepvDY+9 l7tA== 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=r3a/c2oMd9v69Zdf5hDPreXO2X9N0YgX5307ChuDaW4=; b=SR8gntWmgeV/PT+lleRrpRnVoLkRDoena7e1GS+u5oM+uRnoZgi1JwluL6QT+7Mig4 PaIy9WGAFrjvbp98eB/fiW1JzkckB6mIdrJj+5G0NvMuTfd00bPhKVs0UF6MQEoYANno faS7ORWhQHj4hV4DZYf9OU/wCUH3wfujegBQRMKfYXjRZR7ThJHnz1fnOqdYypw0yVed Jtfp/t+3ABG1nTQXxPwKh78KgMrMWSt1S4bIz/dvc+qdsKb9eY3uXteOfHk65QDHO6mB V4WF37ql2lGxq0OGaeijQpdoWe+Galou2dZMVhHjIr1CoZeijvlYvsOpJFBHrFSCxbN/ NanQ== X-Gm-Message-State: APzg51BX7jQAC3Kx8SgLedU7PZHEihn1NFjryqEYBl71bmYTG7BL2N03 HdCmTndTZvilm8g6ajPSfcjZWQ== X-Google-Smtp-Source: ANB0VdYQlu4e030UvBbK8XZiqMko5tpQYCmK0oySI1d1MvpAPFm6pdBQGKpE9HWiHelNbgvdlXabhA== X-Received: by 2002:a50:b941:: with SMTP id m59-v6mr8826970ede.20.1536327527129; Fri, 07 Sep 2018 06:38:47 -0700 (PDT) Received: from maco.fra.corp.google.com (a83-162-234-235.adsl.xs4all.nl. [83.162.234.235]) by smtp.gmail.com with ESMTPSA id v49-v6sm2120857edc.10.2018.09.07.06.38.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 Sep 2018 06:38:46 -0700 (PDT) From: Martijn Coenen To: gregkh@linuxfoundation.org, tkjos@google.com, arve@android.com, dan.carpenter@oracle.com Cc: john.stultz@linaro.org, amit.pundir@linaro.org, smoreland@google.com, peskal@google.com, robenea@google.com, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, maco@google.com, Martijn Coenen Subject: [PATCH v2] ANDROID: binder: Add BINDER_GET_NODE_INFO_FOR_REF ioctl. Date: Fri, 7 Sep 2018 15:38:37 +0200 Message-Id: <20180907133837.66047-1-maco@android.com> X-Mailer: git-send-email 2.19.0.rc2.392.g5ba43deb5a-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This allows the context manager to retrieve information about nodes that it holds a reference to, such as the current number of references to those nodes. Such information can for example be used to determine whether the servicemanager is the only process holding a reference to a node. This information can then be passed on to the process holding the node, which can in turn decide whether it wants to shut down to reduce resource usage. Signed-off-by: Martijn Coenen --- v2: made sure reserved fields are aligned, and enforce caller zeroes all fields except handle, as suggested by Dan Carpenter. drivers/android/binder.c | 55 +++++++++++++++++++++++++++++ include/uapi/linux/android/binder.h | 10 ++++++ 2 files changed, 65 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index d58763b6b0090..5b25412e15ccf 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -4544,6 +4544,42 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp) return ret; } +static int binder_ioctl_get_node_info_for_ref(struct binder_proc *proc, + struct binder_node_info_for_ref *info) +{ + struct binder_node *node; + struct binder_context *context = proc->context; + __u32 handle = info->handle; + + if (info->strong_count || info->weak_count || info->reserved1 || + info->reserved2 || info->reserved3) { + binder_user_error("%d BINDER_GET_NODE_INFO_FOR_REF: only handle may be non-zero.", + proc->pid); + return -EINVAL; + } + + /* This ioctl may only be used by the context manager */ + mutex_lock(&context->context_mgr_node_lock); + if (!context->binder_context_mgr_node || + context->binder_context_mgr_node->proc != proc) { + mutex_unlock(&context->context_mgr_node_lock); + return -EPERM; + } + mutex_unlock(&context->context_mgr_node_lock); + + node = binder_get_node_from_ref(proc, handle, true, NULL); + if (!node) + return -EINVAL; + + info->strong_count = node->local_strong_refs + + node->internal_strong_refs; + info->weak_count = node->local_weak_refs; + + binder_put_node(node); + + return 0; +} + static int binder_ioctl_get_node_debug_info(struct binder_proc *proc, struct binder_node_debug_info *info) { @@ -4638,6 +4674,25 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) } break; } + case BINDER_GET_NODE_INFO_FOR_REF: { + struct binder_node_info_for_ref info; + + if (copy_from_user(&info, ubuf, sizeof(info))) { + ret = -EFAULT; + goto err; + } + + ret = binder_ioctl_get_node_info_for_ref(proc, &info); + if (ret < 0) + goto err; + + if (copy_to_user(ubuf, &info, sizeof(info))) { + ret = -EFAULT; + goto err; + } + + break; + } case BINDER_GET_NODE_DEBUG_INFO: { struct binder_node_debug_info info; diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index bfaec6903b8bc..b9ba520f7e4bb 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -200,6 +200,15 @@ struct binder_node_debug_info { __u32 has_weak_ref; }; +struct binder_node_info_for_ref { + __u32 handle; + __u32 strong_count; + __u32 weak_count; + __u32 reserved1; + __u32 reserved2; + __u32 reserved3; +}; + #define BINDER_WRITE_READ _IOWR('b', 1, struct binder_write_read) #define BINDER_SET_IDLE_TIMEOUT _IOW('b', 3, __s64) #define BINDER_SET_MAX_THREADS _IOW('b', 5, __u32) @@ -208,6 +217,7 @@ struct binder_node_debug_info { #define BINDER_THREAD_EXIT _IOW('b', 8, __s32) #define BINDER_VERSION _IOWR('b', 9, struct binder_version) #define BINDER_GET_NODE_DEBUG_INFO _IOWR('b', 11, struct binder_node_debug_info) +#define BINDER_GET_NODE_INFO_FOR_REF _IOWR('b', 12, struct binder_node_info_for_ref) /* * NOTE: Two special error codes you should check for when calling -- 2.19.0.rc2.392.g5ba43deb5a-goog