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[34.125.23.200]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-218a1e64672sm79920155ad.216.2024.12.18.12.37.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2024 12:37:49 -0800 (PST) From: Li Li To: dualli@google.com, corbet@lwn.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, donald.hunter@gmail.com, gregkh@linuxfoundation.org, arve@android.com, tkjos@android.com, maco@android.com, joel@joelfernandes.org, brauner@kernel.org, cmllamas@google.com, surenb@google.com, arnd@arndb.de, masahiroy@kernel.org, bagasdotme@gmail.com, horms@kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, netdev@vger.kernel.org, hridya@google.com, smoreland@google.com Cc: kernel-team@android.com Subject: [PATCH v11 1/2] binderfs: add new binder devices to binder_devices Date: Wed, 18 Dec 2024 12:37:39 -0800 Message-ID: <20241218203740.4081865-2-dualli@chromium.org> X-Mailer: git-send-email 2.47.1.613.gc27f4b7a9f-goog In-Reply-To: <20241218203740.4081865-1-dualli@chromium.org> References: <20241218203740.4081865-1-dualli@chromium.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Li Li When binderfs is not enabled, the binder driver parses the kernel config to create all binder devices. All of the new binder devices are stored in the list binder_devices. When binderfs is enabled, the binder driver creates new binder devices dynamically when userspace applications call BINDER_CTL_ADD ioctl. But the devices created in this way are not stored in the same list. This patch fixes that. Signed-off-by: Li Li Acked-by: Carlos Llamas --- drivers/android/binder.c | 5 +++++ drivers/android/binder_internal.h | 11 +++++++++-- drivers/android/binderfs.c | 2 ++ 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index ef353ca13c35..0a16acd29653 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -6928,6 +6928,11 @@ const struct binder_debugfs_entry binder_debugfs_entries[] = { {} /* terminator */ }; +void binder_add_device(struct binder_device *device) +{ + hlist_add_head(&device->hlist, &binder_devices); +} + static int __init init_binder_device(const char *name) { int ret; diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h index f8d6be682f23..e4eb8357989c 100644 --- a/drivers/android/binder_internal.h +++ b/drivers/android/binder_internal.h @@ -25,8 +25,7 @@ struct binder_context { /** * struct binder_device - information about a binder device node - * @hlist: list of binder devices (only used for devices requested via - * CONFIG_ANDROID_BINDER_DEVICES) + * @hlist: list of binder devices * @miscdev: information about a binder character device node * @context: binder context information * @binderfs_inode: This is the inode of the root dentry of the super block @@ -582,4 +581,12 @@ struct binder_object { }; }; +/** + * Add a binder device to binder_devices + * @device: the new binder device to add to the global list + * + * Not reentrant as the list is not protected by any locks + */ +void binder_add_device(struct binder_device *device); + #endif /* _LINUX_BINDER_INTERNAL_H */ diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c index ad1fa7abc323..bc6bae76ccaf 100644 --- a/drivers/android/binderfs.c +++ b/drivers/android/binderfs.c @@ -207,6 +207,8 @@ static int binderfs_binder_device_create(struct inode *ref_inode, fsnotify_create(root->d_inode, dentry); inode_unlock(d_inode(root)); + binder_add_device(device); + return 0; err: From patchwork Wed Dec 18 20:37:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Li X-Patchwork-Id: 13914146 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 015A11FCD12 for ; 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[34.125.23.200]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-218a1e64672sm79920155ad.216.2024.12.18.12.37.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2024 12:37:50 -0800 (PST) From: Li Li To: dualli@google.com, corbet@lwn.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, donald.hunter@gmail.com, gregkh@linuxfoundation.org, arve@android.com, tkjos@android.com, maco@android.com, joel@joelfernandes.org, brauner@kernel.org, cmllamas@google.com, surenb@google.com, arnd@arndb.de, masahiroy@kernel.org, bagasdotme@gmail.com, horms@kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, netdev@vger.kernel.org, hridya@google.com, smoreland@google.com Cc: kernel-team@android.com Subject: [PATCH v11 2/2] binder: report txn errors via generic netlink Date: Wed, 18 Dec 2024 12:37:40 -0800 Message-ID: <20241218203740.4081865-3-dualli@chromium.org> X-Mailer: git-send-email 2.47.1.613.gc27f4b7a9f-goog In-Reply-To: <20241218203740.4081865-1-dualli@chromium.org> References: <20241218203740.4081865-1-dualli@chromium.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Li Li Introduce generic netlink messages into the binder driver so that the Linux/Android system administration process can listen to important events and take corresponding actions, like stopping a broken app from attacking the OS by sending huge amount of spamming binder transactions. The binder netlink sources and headers are automatically generated from the corresponding binder netlink YAML spec. Don't modify them directly. Signed-off-by: Li Li --- Documentation/admin-guide/binder_netlink.rst | 110 +++++++++ Documentation/admin-guide/index.rst | 1 + Documentation/netlink/specs/binder.yaml | 108 +++++++++ drivers/android/Kconfig | 1 + drivers/android/Makefile | 2 +- drivers/android/binder.c | 236 ++++++++++++++++++- drivers/android/binder_internal.h | 18 ++ drivers/android/binder_netlink.c | 39 +++ drivers/android/binder_netlink.h | 18 ++ drivers/android/binder_trace.h | 35 +++ include/uapi/linux/android/binder_netlink.h | 55 +++++ 11 files changed, 619 insertions(+), 4 deletions(-) create mode 100644 Documentation/admin-guide/binder_netlink.rst create mode 100644 Documentation/netlink/specs/binder.yaml create mode 100644 drivers/android/binder_netlink.c create mode 100644 drivers/android/binder_netlink.h create mode 100644 include/uapi/linux/android/binder_netlink.h diff --git a/Documentation/admin-guide/binder_netlink.rst b/Documentation/admin-guide/binder_netlink.rst new file mode 100644 index 000000000000..71b4c6596c5b --- /dev/null +++ b/Documentation/admin-guide/binder_netlink.rst @@ -0,0 +1,110 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================================================== +Generic Netlink for the Android Binder Driver (Binder Netlink) +============================================================== + +The Generic Netlink subsystem in the Linux kernel provides a generic way for +the Linux kernel to communicate with the user space applications via binder +driver. It is used to report binder transaction errors and warnings to user +space administration process. The driver allows multiple binder devices and +their corresponding binder contexts. Each context has an independent Generic +Netlink for security reason. To prevent untrusted user applications from +accessing the netlink data, the kernel driver uses unicast mode instead of +multicast. + +Basically, the user space code uses the BINDER_NETLINK_CMD_REPORT_SETUP +command to request what kind of binder transactions should be reported by +the driver. The driver then echoes the attributes in a reply message to +acknowledge the request. The BINDER_NETLINK_CMD_REPORT_SETUP command also +registers the current user space process to receive the reports. When the +user space process exits, the previous request will be reset automatically. + +Currently the driver reports these binder transaction errors and warnings. +1. "FAILED" transactions that fail to reach the target process; +2. "ASYNC_FROZEN" transactions that are delayed due to the target process +being frozen by cgroup freezer; or +3. "SPAM" transactions that are considered spamming according to existing +logic in binder_alloc.c. + +When the specified binder transactions happen, the driver uses the +BINDER_NETLINK_CMD_REPORT command to send a generic netlink message to the +registered process, containing the payload defined in binder_netlink.yaml. + +More details about the flags, attributes and operations can be found at the +the doc sections in Documentations/netlink/specs/binder_netlink.yaml and the +kernel-doc comments of the new source code in binder.{h|c}. + +Using Binder Netlink +-------------------- + +The Binder Netlink can be used in the same way as any other generic netlink +drivers. Userspace application uses a raw netlink socket to send commands +to and receive packets from the kernel driver. + +.. note:: + If the userspace application that talks to the driver exits, the kernel + driver will automatically reset the configuration to the default and + stop sending more reports, which would otherwise fail. + +Usage example (user space pseudo code): + +:: + /* + * send() below is overloaded to pack netlink commands and attributes + * to nlattr/genlmsghdr/nlmsghdr and then send to the netlink socket. + * + * recv() below is overloaded to receive the raw netlink message from + * the netlink socket, parse nlmsghdr/genlmsghdr to find the netlink + * command and then return the nlattr payload. + */ + + // open netlink socket + int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); + + // bind netlink socket + bind(fd, struct socketaddr); + + // get the family id of the binder netlink + send(fd, CTRL_CMD_GETFAMILY, CTRL_ATTR_FAMILY_NAME, + BINDER_NETLINK_FAMILY_NAME); + void *data = recv(CTRL_CMD_NEWFAMILY); + if (!has_nla_type(data, CTRL_ATTR_FAMILY_ID)) { + // Binder Netlink isn't available on this version of Linux kernel + return; + } + __u16 id = nla(data)[CTRL_ATTR_FAMILY_ID]; + + // enable per-context binder report + send(fd, id, BINDER_NETLINK_CMD_REPORT_SETUP, "binder", 0, + BINDER_NETLINK_FLAG_FAILED | BINDER_NETLINK_FLAG_DELAYED); + + // confirm the per-context configuration + data = recv(fd, BINDER_NETLINK_CMD_REPLY); + char *context = nla(data)[BINDER_NETLINK_A_CMD_CONTEXT]; + __u32 pid = nla(data)[BINDER_NETLINK_A_CMD_PID]; + __u32 flags = nla(data)[BINDER_NETLINK_A_CMD_FLAGS]; + + // set optional per-process report, overriding the per-context one + send(fd, id, BINDER_NETLINK_CMD_REPORT_SETUP, "binder", getpid(), + BINDER_NETLINK_FLAG_SPAM | BINDER_REPORT_OVERRIDE); + + // confirm the optional per-process configuration + data = recv(fd, BINDER_NETLINK_CMD_REPLY); + context = nla(data)[BINDER_NETLINK_A_CMD_CONTEXT]; + pid = nla(data)[BINDER_NETLINK_A_CMD_PID]; + flags = nla(data)[BINDER_NETLINK_A_CMD_FLAGS]; + + // wait and read all binder reports + while (running) { + data = recv(fd, BINDER_NETLINK_CMD_REPORT); + auto *attr = nla(data)[BINDER_NETLINK_A_REPORT_XXX]; + + // process binder report + do_something(*attr); + } + + // clean up + send(fd, id, BINDER_NETLINK_CMD_REPORT_SETUP, 0, 0); + send(fd, id, BINDER_NETLINK_CMD_REPORT_SETUP, getpid(), 0); + close(fd); diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst index e85b1adf5908..7ab2cec2fe9f 100644 --- a/Documentation/admin-guide/index.rst +++ b/Documentation/admin-guide/index.rst @@ -79,6 +79,7 @@ configure specific aspects of kernel behavior to your liking. aoe/index auxdisplay/index bcache + binder_netlink binderfs binfmt-misc blockdev/index diff --git a/Documentation/netlink/specs/binder.yaml b/Documentation/netlink/specs/binder.yaml new file mode 100644 index 000000000000..23f26c83a7c9 --- /dev/null +++ b/Documentation/netlink/specs/binder.yaml @@ -0,0 +1,108 @@ +# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) + +name: binder +protocol: genetlink +uapi-header: linux/android/binder_netlink.h +doc: Netlink protocol to report binder transaction errors and warnings. + +definitions: + - + type: flags + name: flag + doc: Define what kind of binder transactions should be reported. + entries: [ failed, async-frozen, spam, override ] + +attribute-sets: + - + name: cmd + doc: The supported attributes of "report-setup" command. + attributes: + - + name: context + type: string + doc: The binder context to enable binder netlink report. + - + name: pid + type: u32 + doc: The binder proc to enable binder netlink report. + - + name: flags + type: u32 + enum: flag + doc: What kind of binder transactions should be reported. + - + name: report + doc: The supported attributes of "report" command + attributes: + - + name: context + type: string + doc: The binder context where the binder netlink report happens. + - + name: err + type: u32 + doc: Copy of binder_driver_return_protocol returned to the sender. + - + name: from_pid + type: u32 + doc: Sender pid of the corresponding binder transaction. + - + name: from_tid + type: u32 + doc: Sender tid of the corresponding binder transaction. + - + name: to_pid + type: u32 + doc: Target pid of the corresponding binder transaction. + - + name: to_tid + type: u32 + doc: Target tid of the corresponding binder transaction. + - + name: reply + type: u32 + doc: 1 means the transaction is a reply, 0 otherwise. + - + name: flags + type: u32 + doc: Copy of binder_transaction_data->flags. + - + name: code + type: u32 + doc: Copy of binder_transaction_data->code. + - + name: data_size + type: u32 + doc: Copy of binder_transaction_data->data_size. + +operations: + list: + - + name: report-setup + doc: Set flags from user space. + attribute-set: cmd + + do: + request: ¶ms + attributes: + - context + - pid + - flags + reply: *params + - + name: report + doc: Send the requested reports to user space. + attribute-set: report + + event: + attributes: + - context + - err + - from_pid + - from_tid + - to_pid + - to_tid + - reply + - flags + - code + - data_size diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig index 07aa8ae0a058..e2fa620934e2 100644 --- a/drivers/android/Kconfig +++ b/drivers/android/Kconfig @@ -4,6 +4,7 @@ menu "Android" config ANDROID_BINDER_IPC bool "Android Binder IPC Driver" depends on MMU + depends on NET default n help Binder is used in Android for both communication between processes, diff --git a/drivers/android/Makefile b/drivers/android/Makefile index c9d3d0c99c25..b8874dba884e 100644 --- a/drivers/android/Makefile +++ b/drivers/android/Makefile @@ -2,5 +2,5 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_ANDROID_BINDERFS) += binderfs.o -obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o +obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o binder_netlink.o obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 0a16acd29653..536be42c531e 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -72,6 +72,7 @@ #include +#include "binder_netlink.h" #include "binder_internal.h" #include "binder_trace.h" @@ -2990,6 +2991,111 @@ static void binder_set_txn_from_error(struct binder_transaction *t, int id, binder_thread_dec_tmpref(from); } +/** + * binder_find_proc() - find the binder_proc by pid + * @pid: the target process + * + * Returns the struct binder_proc if the pid is found, or NULL otherwise. + */ +static struct binder_proc *binder_find_proc(int pid) +{ + struct binder_proc *proc; + + mutex_lock(&binder_procs_lock); + hlist_for_each_entry(proc, &binder_procs, proc_node) { + if (proc->pid == pid) + break; + } + mutex_unlock(&binder_procs_lock); + + return proc; +} + +/** + * binder_netlink_enabled() - check if binder netlink reports are enabled + * @proc: the binder_proc to check + * @mask: the categories of binder netlink reports + * + * Returns true if certain binder netlink reports are enabled for this binder + * proc (when per-process overriding takes effect) or context. + */ +static bool binder_netlink_enabled(struct binder_proc *proc, u32 mask) +{ + struct binder_context *context = proc->context; + + if (!context->report_portid) + return false; + + if (proc->report_flags & BINDER_FLAG_OVERRIDE) + return (proc->report_flags & mask) != 0; + else + return (context->report_flags & mask) != 0; +} + +/** + * binder_netlink_report() - report one binder netlink event + * @context: the binder context + * @err: copy of binder_driver_return_protocol returned to the sender + * @pid: sender process + * @tid: sender thread + * @to_pid: target process + * @to_tid: target thread + * @reply: whether the binder transaction is a reply + * @tr: the binder transaction data + * + * Packs the report data into a binder netlink message and send it. + */ +static void binder_netlink_report(struct binder_context *context, u32 err, + u32 pid, u32 tid, u32 to_pid, u32 to_tid, + u32 reply, + struct binder_transaction_data *tr) +{ + struct sk_buff *skb; + void *hdr; + int ret; + + trace_binder_netlink_report(context->name, err, pid, tid, to_pid, + to_tid, reply, tr); + + skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!skb) { + pr_err("Failed to alloc binder netlink message\n"); + return; + } + + hdr = genlmsg_put(skb, 0, atomic_inc_return(&context->report_seq), + &binder_nl_family, 0, BINDER_CMD_REPORT); + if (!hdr) + goto free_skb; + + if (nla_put_string(skb, BINDER_A_REPORT_CONTEXT, context->name) || + nla_put_u32(skb, BINDER_A_REPORT_ERR, err) || + nla_put_u32(skb, BINDER_A_REPORT_FROM_PID, pid) || + nla_put_u32(skb, BINDER_A_REPORT_FROM_TID, tid) || + nla_put_u32(skb, BINDER_A_REPORT_TO_PID, to_pid) || + nla_put_u32(skb, BINDER_A_REPORT_TO_TID, to_tid) || + nla_put_u32(skb, BINDER_A_REPORT_REPLY, reply) || + nla_put_u32(skb, BINDER_A_REPORT_FLAGS, tr->flags) || + nla_put_u32(skb, BINDER_A_REPORT_CODE, tr->code) || + nla_put_u32(skb, BINDER_A_REPORT_DATA_SIZE, tr->data_size)) + goto cancel_skb; + + genlmsg_end(skb, hdr); + + ret = genlmsg_unicast(&init_net, skb, context->report_portid); + if (ret < 0) + pr_err("Failed to send binder netlink message to %d: %d\n", + context->report_portid, ret); + return; + +cancel_skb: + pr_err("Failed to add attributes to binder netlink message\n"); + genlmsg_cancel(skb, hdr); +free_skb: + pr_err("Free binder netlink report message on error\n"); + nlmsg_free(skb); +} + static void binder_transaction(struct binder_proc *proc, struct binder_thread *thread, struct binder_transaction_data *tr, int reply, @@ -3684,10 +3790,17 @@ static void binder_transaction(struct binder_proc *proc, return_error_line = __LINE__; goto err_copy_data_failed; } - if (t->buffer->oneway_spam_suspect) + if (t->buffer->oneway_spam_suspect) { tcomplete->type = BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT; - else + if (binder_netlink_enabled(proc, BINDER_FLAG_SPAM)) + binder_netlink_report(context, BR_ONEWAY_SPAM_SUSPECT, + proc->pid, thread->pid, + target_proc ? target_proc->pid : 0, + target_thread ? target_thread->pid : 0, + reply, tr); + } else { tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE; + } t->work.type = BINDER_WORK_TRANSACTION; if (reply) { @@ -3737,8 +3850,15 @@ static void binder_transaction(struct binder_proc *proc, * process and is put in a pending queue, waiting for the target * process to be unfrozen. */ - if (return_error == BR_TRANSACTION_PENDING_FROZEN) + if (return_error == BR_TRANSACTION_PENDING_FROZEN) { tcomplete->type = BINDER_WORK_TRANSACTION_PENDING; + if (binder_netlink_enabled(proc, BINDER_FLAG_ASYNC_FROZEN)) + binder_netlink_report(context, return_error, + proc->pid, thread->pid, + target_proc ? target_proc->pid : 0, + target_thread ? target_thread->pid : 0, + reply, tr); + } binder_enqueue_thread_work(thread, tcomplete); if (return_error && return_error != BR_TRANSACTION_PENDING_FROZEN) @@ -3800,6 +3920,13 @@ static void binder_transaction(struct binder_proc *proc, binder_dec_node_tmpref(target_node); } + if (binder_netlink_enabled(proc, BINDER_FLAG_FAILED)) + binder_netlink_report(context, return_error, + proc->pid, thread->pid, + target_proc ? target_proc->pid : 0, + target_thread ? target_thread->pid : 0, + reply, tr); + binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, "%d:%d transaction %s to %d:%d failed %d/%d/%d, size %lld-%lld line %d\n", proc->pid, thread->pid, reply ? "reply" : @@ -6137,6 +6264,11 @@ static int binder_release(struct inode *nodp, struct file *filp) binder_defer_work(proc, BINDER_DEFERRED_RELEASE); + if (proc->pid == proc->context->report_portid) { + proc->context->report_portid = 0; + proc->context->report_flags = 0; + } + return 0; } @@ -6335,6 +6467,98 @@ binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer) mutex_unlock(&binder_deferred_lock); } +/** + * binder_nl_report_setup_doit() - netlink .doit handler + * @skb: the metadata struct passed from netlink driver + * @info: the generic netlink struct passed from netlink driver + * + * Implements the .doit function to process binder netlink commands. + */ +int binder_nl_report_setup_doit(struct sk_buff *skb, struct genl_info *info) +{ + struct binder_context *context = NULL; + struct binder_device *device; + struct binder_proc *proc; + u32 flags, pid; + int portid; + void *hdr; + + hlist_for_each_entry(device, &binder_devices, hlist) { + if (!nla_strcmp(info->attrs[BINDER_A_CMD_CONTEXT], + device->context.name)) { + context = &device->context; + break; + } + } + + if (!context) { + NL_SET_ERR_MSG(info->extack, "Unknown binder context"); + return -EINVAL; + } + + portid = nlmsg_hdr(skb)->nlmsg_pid; + pid = nla_get_u32(info->attrs[BINDER_A_CMD_PID]); + flags = nla_get_u32(info->attrs[BINDER_A_CMD_FLAGS]); + + if (context->report_portid && context->report_portid != portid) { + NL_SET_ERR_MSG_FMT(info->extack, + "No permission to set flags from %d", + portid); + return -EPERM; + } + + if (!pid) { + /* Set the global flags for the whole binder context */ + context->report_flags = flags; + } else { + /* Set the per-process flags */ + proc = binder_find_proc(pid); + if (!proc) { + NL_SET_ERR_MSG_FMT(info->extack, + "Invalid binder report pid %u", + pid); + return -EINVAL; + } + + proc->report_flags = flags; + } + + skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!skb) { + pr_err("Failed to alloc binder netlink reply message\n"); + return -ENOMEM; + } + + hdr = genlmsg_iput(skb, info); + if (!hdr) + goto free_skb; + + if (nla_put_string(skb, BINDER_A_CMD_CONTEXT, context->name) || + nla_put_u32(skb, BINDER_A_CMD_PID, pid) || + nla_put_u32(skb, BINDER_A_CMD_FLAGS, flags)) + goto cancel_skb; + + genlmsg_end(skb, hdr); + + if (genlmsg_reply(skb, info)) { + pr_err("Failed to send binder netlink reply message\n"); + return -EFAULT; + } + + if (!context->report_portid) + context->report_portid = portid; + + return 0; + +cancel_skb: + pr_err("Failed to add reply attributes to binder netlink message\n"); + genlmsg_cancel(skb, hdr); +free_skb: + pr_err("Free binder netlink reply message on error\n"); + nlmsg_free(skb); + return -EMSGSIZE; +} + static void print_binder_transaction_ilocked(struct seq_file *m, struct binder_proc *proc, const char *prefix, @@ -7014,6 +7238,12 @@ static int __init binder_init(void) if (ret) goto err_init_binder_device_failed; + ret = genl_register_family(&binder_nl_family); + if (ret) { + pr_err("Failed to register binder netlink family\n"); + goto err_init_binder_device_failed; + } + return ret; err_init_binder_device_failed: diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h index e4eb8357989c..c67eba88f89a 100644 --- a/drivers/android/binder_internal.h +++ b/drivers/android/binder_internal.h @@ -12,15 +12,30 @@ #include #include #include +#include #include #include "binder_alloc.h" #include "dbitmap.h" +/** + * struct binder_context - information about a binder domain + * @binder_context_mgr_node: the context manager + * @context_mgr_node_lock: the lock protecting the above context manager node + * @binder_context_mgr_uid: the uid of the above context manager + * @name: the name of the binder device + * @report_portid: the netlink socket to receive binder reports + * @report_flags: the categories of binder transactions that would + * be reported (see enum binder_report_flag). + * @report_seq: the seq number of the generic netlink report + */ struct binder_context { struct binder_node *binder_context_mgr_node; struct mutex context_mgr_node_lock; kuid_t binder_context_mgr_uid; const char *name; + u32 report_portid; + u32 report_flags; + atomic_t report_seq; }; /** @@ -414,6 +429,8 @@ struct binder_ref { * @binderfs_entry: process-specific binderfs log file * @oneway_spam_detection_enabled: process enabled oneway spam detection * or not + * @report_flags: the categories of binder transactions that would + * be reported (see enum binder_genl_flag). * * Bookkeeping structure for binder processes */ @@ -452,6 +469,7 @@ struct binder_proc { spinlock_t outer_lock; struct dentry *binderfs_entry; bool oneway_spam_detection_enabled; + u32 report_flags; }; /** diff --git a/drivers/android/binder_netlink.c b/drivers/android/binder_netlink.c new file mode 100644 index 000000000000..ea008f4f3635 --- /dev/null +++ b/drivers/android/binder_netlink.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) +/* Do not edit directly, auto-generated from: */ +/* Documentation/netlink/specs/binder.yaml */ +/* YNL-GEN kernel source */ + +#include +#include + +#include "binder_netlink.h" + +#include + +/* BINDER_CMD_REPORT_SETUP - do */ +static const struct nla_policy binder_report_setup_nl_policy[BINDER_A_CMD_FLAGS + 1] = { + [BINDER_A_CMD_CONTEXT] = { .type = NLA_NUL_STRING, }, + [BINDER_A_CMD_PID] = { .type = NLA_U32, }, + [BINDER_A_CMD_FLAGS] = NLA_POLICY_MASK(NLA_U32, 0xf), +}; + +/* Ops table for binder */ +static const struct genl_split_ops binder_nl_ops[] = { + { + .cmd = BINDER_CMD_REPORT_SETUP, + .doit = binder_nl_report_setup_doit, + .policy = binder_report_setup_nl_policy, + .maxattr = BINDER_A_CMD_FLAGS, + .flags = GENL_CMD_CAP_DO, + }, +}; + +struct genl_family binder_nl_family __ro_after_init = { + .name = BINDER_FAMILY_NAME, + .version = BINDER_FAMILY_VERSION, + .netnsok = true, + .parallel_ops = true, + .module = THIS_MODULE, + .split_ops = binder_nl_ops, + .n_split_ops = ARRAY_SIZE(binder_nl_ops), +}; diff --git a/drivers/android/binder_netlink.h b/drivers/android/binder_netlink.h new file mode 100644 index 000000000000..de18dc107c70 --- /dev/null +++ b/drivers/android/binder_netlink.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */ +/* Do not edit directly, auto-generated from: */ +/* Documentation/netlink/specs/binder.yaml */ +/* YNL-GEN kernel header */ + +#ifndef _LINUX_BINDER_GEN_H +#define _LINUX_BINDER_GEN_H + +#include +#include + +#include + +int binder_nl_report_setup_doit(struct sk_buff *skb, struct genl_info *info); + +extern struct genl_family binder_nl_family; + +#endif /* _LINUX_BINDER_GEN_H */ diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h index fe38c6fc65d0..8976fb5ee2db 100644 --- a/drivers/android/binder_trace.h +++ b/drivers/android/binder_trace.h @@ -423,6 +423,41 @@ TRACE_EVENT(binder_return, "unknown") ); +TRACE_EVENT(binder_netlink_report, + TP_PROTO(const char *name, u32 err, u32 pid, u32 tid, u32 to_pid, + u32 to_tid, u32 reply, struct binder_transaction_data *tr), + TP_ARGS(name, err, pid, tid, to_pid, to_tid, reply, tr), + TP_STRUCT__entry( + __field(const char *, name) + __field(u32, err) + __field(u32, pid) + __field(u32, tid) + __field(u32, to_pid) + __field(u32, to_tid) + __field(u32, reply) + __field(u32, flags) + __field(u32, code) + __field(binder_size_t, data_size) + ), + TP_fast_assign( + __entry->name = name; + __entry->err = err; + __entry->pid = pid; + __entry->tid = tid; + __entry->to_pid = to_pid; + __entry->to_tid = to_tid; + __entry->reply = reply; + __entry->flags = tr->flags; + __entry->code = tr->code; + __entry->data_size = tr->data_size; + ), + TP_printk("%s: %d %d:%d -> %d:%d %s flags=0x08%x code=%d %llu", + __entry->name, __entry->err, __entry->pid, __entry->tid, + __entry->to_pid, __entry->to_tid, + __entry->reply ? "reply" : "", + __entry->flags, __entry->code, __entry->data_size) +); + #endif /* _BINDER_TRACE_H */ #undef TRACE_INCLUDE_PATH diff --git a/include/uapi/linux/android/binder_netlink.h b/include/uapi/linux/android/binder_netlink.h new file mode 100644 index 000000000000..d6504c267516 --- /dev/null +++ b/include/uapi/linux/android/binder_netlink.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */ +/* Do not edit directly, auto-generated from: */ +/* Documentation/netlink/specs/binder.yaml */ +/* YNL-GEN uapi header */ + +#ifndef _UAPI_LINUX_ANDROID_BINDER_NETLINK_H +#define _UAPI_LINUX_ANDROID_BINDER_NETLINK_H + +#define BINDER_FAMILY_NAME "binder" +#define BINDER_FAMILY_VERSION 1 + +/* + * Define what kind of binder transactions should be reported. + */ +enum binder_flag { + BINDER_FLAG_FAILED = 1, + BINDER_FLAG_ASYNC_FROZEN = 2, + BINDER_FLAG_SPAM = 4, + BINDER_FLAG_OVERRIDE = 8, +}; + +enum { + BINDER_A_CMD_CONTEXT = 1, + BINDER_A_CMD_PID, + BINDER_A_CMD_FLAGS, + + __BINDER_A_CMD_MAX, + BINDER_A_CMD_MAX = (__BINDER_A_CMD_MAX - 1) +}; + +enum { + BINDER_A_REPORT_CONTEXT = 1, + BINDER_A_REPORT_ERR, + BINDER_A_REPORT_FROM_PID, + BINDER_A_REPORT_FROM_TID, + BINDER_A_REPORT_TO_PID, + BINDER_A_REPORT_TO_TID, + BINDER_A_REPORT_REPLY, + BINDER_A_REPORT_FLAGS, + BINDER_A_REPORT_CODE, + BINDER_A_REPORT_DATA_SIZE, + + __BINDER_A_REPORT_MAX, + BINDER_A_REPORT_MAX = (__BINDER_A_REPORT_MAX - 1) +}; + +enum { + BINDER_CMD_REPORT_SETUP = 1, + BINDER_CMD_REPORT, + + __BINDER_CMD_MAX, + BINDER_CMD_MAX = (__BINDER_CMD_MAX - 1) +}; + +#endif /* _UAPI_LINUX_ANDROID_BINDER_NETLINK_H */