Re: [PATCH] staging: android: binder.c: binder_ioctl() cleanup

From: Brian Swetland
Date: Wed Jun 04 2014 - 02:22:38 EST


Arve's probably the best person to loop in on binder driver patches
(considering he wrote it).

Brian

On Tue, Jun 3, 2014 at 12:27 PM, Tair Rzayev <tair.rzayev@xxxxxxxxx> wrote:
> binder_ioctl() is quite huge and checkpatch dirty - mostly because of
> the amount of code for the BINDER_WRITE_READ and BINDER_SET_CONTEXT_MGR.
> Moved that code into the new binder_ioctl_write_read() and
> binder_ioctl_set_ctx_mgr()
>
> Signed-off-by: Tair Rzayev <tair.rzayev@xxxxxxxxx>
> ---
> drivers/staging/android/binder.c | 186 ++++++++++++++++++++++-----------------
> 1 file changed, 107 insertions(+), 79 deletions(-)
>
> diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
> index 989f809..ed432e3 100644
> --- a/drivers/staging/android/binder.c
> +++ b/drivers/staging/android/binder.c
> @@ -2594,6 +2594,106 @@ static unsigned int binder_poll(struct file *filp,
> return 0;
> }
>
> +static int binder_ioctl_write_read(struct file *filp,
> + unsigned int cmd, unsigned long arg,
> + struct binder_thread *thread)
> +{
> + int ret = 0;
> + struct binder_proc *proc = filp->private_data;
> + unsigned int size = _IOC_SIZE(cmd);
> + void __user *ubuf = (void __user *)arg;
> + struct binder_write_read bwr;
> +
> + if (size != sizeof(struct binder_write_read)) {
> + ret = -EINVAL;
> + goto out;
> + }
> + if (copy_from_user(&bwr, ubuf, sizeof(bwr))) {
> + ret = -EFAULT;
> + goto out;
> + }
> + binder_debug(BINDER_DEBUG_READ_WRITE,
> + "%d:%d write %lld at %016llx, read %lld at %016llx\n",
> + proc->pid, thread->pid,
> + (u64)bwr.write_size, (u64)bwr.write_buffer,
> + (u64)bwr.read_size, (u64)bwr.read_buffer);
> +
> + if (bwr.write_size > 0) {
> + ret = binder_thread_write(proc, thread,
> + bwr.write_buffer,
> + bwr.write_size,
> + &bwr.write_consumed);
> + trace_binder_write_done(ret);
> + if (ret < 0) {
> + bwr.read_consumed = 0;
> + if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
> + ret = -EFAULT;
> + goto out;
> + }
> + }
> + if (bwr.read_size > 0) {
> + ret = binder_thread_read(proc, thread, bwr.read_buffer,
> + bwr.read_size,
> + &bwr.read_consumed,
> + filp->f_flags & O_NONBLOCK);
> + trace_binder_read_done(ret);
> + if (!list_empty(&proc->todo))
> + wake_up_interruptible(&proc->wait);
> + if (ret < 0) {
> + if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
> + ret = -EFAULT;
> + goto out;
> + }
> + }
> + binder_debug(BINDER_DEBUG_READ_WRITE,
> + "%d:%d wrote %lld of %lld, read return %lld of %lld\n",
> + proc->pid, thread->pid,
> + (u64)bwr.write_consumed, (u64)bwr.write_size,
> + (u64)bwr.read_consumed, (u64)bwr.read_size);
> + if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {
> + ret = -EFAULT;
> + goto out;
> + }
> +out:
> + return ret;
> +}
> +
> +static int binder_ioctl_set_ctx_mgr(struct file *filp)
> +{
> + int ret = 0;
> + struct binder_proc *proc = filp->private_data;
> + kuid_t curr_euid = current_euid();
> +
> + if (binder_context_mgr_node != NULL) {
> + pr_err("BINDER_SET_CONTEXT_MGR already set\n");
> + ret = -EBUSY;
> + goto out;
> + }
> + if (uid_valid(binder_context_mgr_uid)) {
> + if (!uid_eq(binder_context_mgr_uid, curr_euid)) {
> + pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n",
> + from_kuid(&init_user_ns, curr_euid),
> + from_kuid(&init_user_ns,
> + binder_context_mgr_uid));
> + ret = -EPERM;
> + goto out;
> + }
> + } else {
> + binder_context_mgr_uid = curr_euid;
> + }
> + binder_context_mgr_node = binder_new_node(proc, 0, 0);
> + if (binder_context_mgr_node == NULL) {
> + ret = -ENOMEM;
> + goto out;
> + }
> + binder_context_mgr_node->local_weak_refs++;
> + binder_context_mgr_node->local_strong_refs++;
> + binder_context_mgr_node->has_strong_ref = 1;
> + binder_context_mgr_node->has_weak_ref = 1;
> +out:
> + return ret;
> +}
> +
> static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> {
> int ret;
> @@ -2601,9 +2701,9 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> struct binder_thread *thread;
> unsigned int size = _IOC_SIZE(cmd);
> void __user *ubuf = (void __user *)arg;
> - kuid_t curr_euid = current_euid();
>
> - /*pr_info("binder_ioctl: %d:%d %x %lx\n", proc->pid, current->pid, cmd, arg);*/
> + /*pr_info("binder_ioctl: %d:%d %x %lx\n",
> + proc->pid, current->pid, cmd, arg);*/
>
> trace_binder_ioctl(cmd, arg);
>
> @@ -2619,61 +2719,11 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> }
>
> switch (cmd) {
> - case BINDER_WRITE_READ: {
> - struct binder_write_read bwr;
> -
> - if (size != sizeof(struct binder_write_read)) {
> - ret = -EINVAL;
> + case BINDER_WRITE_READ:
> + ret = binder_ioctl_write_read(filp, cmd, arg, thread);
> + if (ret)
> goto err;
> - }
> - if (copy_from_user(&bwr, ubuf, sizeof(bwr))) {
> - ret = -EFAULT;
> - goto err;
> - }
> - binder_debug(BINDER_DEBUG_READ_WRITE,
> - "%d:%d write %lld at %016llx, read %lld at %016llx\n",
> - proc->pid, thread->pid,
> - (u64)bwr.write_size, (u64)bwr.write_buffer,
> - (u64)bwr.read_size, (u64)bwr.read_buffer);
> -
> - if (bwr.write_size > 0) {
> - ret = binder_thread_write(proc, thread,
> - bwr.write_buffer,
> - bwr.write_size,
> - &bwr.write_consumed);
> - trace_binder_write_done(ret);
> - if (ret < 0) {
> - bwr.read_consumed = 0;
> - if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
> - ret = -EFAULT;
> - goto err;
> - }
> - }
> - if (bwr.read_size > 0) {
> - ret = binder_thread_read(proc, thread, bwr.read_buffer,
> - bwr.read_size,
> - &bwr.read_consumed,
> - filp->f_flags & O_NONBLOCK);
> - trace_binder_read_done(ret);
> - if (!list_empty(&proc->todo))
> - wake_up_interruptible(&proc->wait);
> - if (ret < 0) {
> - if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
> - ret = -EFAULT;
> - goto err;
> - }
> - }
> - binder_debug(BINDER_DEBUG_READ_WRITE,
> - "%d:%d wrote %lld of %lld, read return %lld of %lld\n",
> - proc->pid, thread->pid,
> - (u64)bwr.write_consumed, (u64)bwr.write_size,
> - (u64)bwr.read_consumed, (u64)bwr.read_size);
> - if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {
> - ret = -EFAULT;
> - goto err;
> - }
> break;
> - }
> case BINDER_SET_MAX_THREADS:
> if (copy_from_user(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
> ret = -EINVAL;
> @@ -2681,31 +2731,9 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> }
> break;
> case BINDER_SET_CONTEXT_MGR:
> - if (binder_context_mgr_node != NULL) {
> - pr_err("BINDER_SET_CONTEXT_MGR already set\n");
> - ret = -EBUSY;
> + ret = binder_ioctl_set_ctx_mgr(filp);
> + if (ret)
> goto err;
> - }
> - if (uid_valid(binder_context_mgr_uid)) {
> - if (!uid_eq(binder_context_mgr_uid, curr_euid)) {
> - pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n",
> - from_kuid(&init_user_ns, curr_euid),
> - from_kuid(&init_user_ns, binder_context_mgr_uid));
> - ret = -EPERM;
> - goto err;
> - }
> - } else {
> - binder_context_mgr_uid = curr_euid;
> - }
> - binder_context_mgr_node = binder_new_node(proc, 0, 0);
> - if (binder_context_mgr_node == NULL) {
> - ret = -ENOMEM;
> - goto err;
> - }
> - binder_context_mgr_node->local_weak_refs++;
> - binder_context_mgr_node->local_strong_refs++;
> - binder_context_mgr_node->has_strong_ref = 1;
> - binder_context_mgr_node->has_weak_ref = 1;
> break;
> case BINDER_THREAD_EXIT:
> binder_debug(BINDER_DEBUG_THREADS, "%d:%d exit\n",
> --
> 1.9.1
>
>
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