From ca2864c6e8965c37df97f11e6f99e83e09806b1c Mon Sep 17 00:00:00 2001 From: Hridya Valsaraju Date: Wed, 4 Sep 2019 13:07:03 +0200 Subject: binder: Add default binder devices through binderfs when configured Currently, since each binderfs instance needs its own private binder devices, every time a binderfs instance is mounted, all the default binder devices need to be created via the BINDER_CTL_ADD IOCTL. This patch aims to add a solution to automatically create the default binder devices for each binderfs instance that gets mounted. To achieve this goal, when CONFIG_ANDROID_BINDERFS is set, the default binder devices specified by CONFIG_ANDROID_BINDER_DEVICES are created in each binderfs instance instead of global devices being created by the binder driver. Co-developed-by: Christian Brauner Signed-off-by: Christian Brauner Signed-off-by: Hridya Valsaraju Reviewed-by: Joel Fernandes (Google) Link: https://lore.kernel.org/r/20190808222727.132744-2-hridya@google.com Link: https://lore.kernel.org/r/20190904110704.8606-2-christian.brauner@ubuntu.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binderfs.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'drivers/android/binderfs.c') diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c index d8307cccbef8..55c5adb87585 100644 --- a/drivers/android/binderfs.c +++ b/drivers/android/binderfs.c @@ -186,8 +186,7 @@ static int binderfs_binder_device_create(struct inode *ref_inode, req->major = MAJOR(binderfs_dev); req->minor = minor; - ret = copy_to_user(userp, req, sizeof(*req)); - if (ret) { + if (userp && copy_to_user(userp, req, sizeof(*req))) { ret = -EFAULT; goto err; } @@ -467,6 +466,9 @@ static int binderfs_fill_super(struct super_block *sb, void *data, int silent) int ret; struct binderfs_info *info; struct inode *inode = NULL; + struct binderfs_device device_info = { 0 }; + const char *name; + size_t len; sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; @@ -521,7 +523,22 @@ static int binderfs_fill_super(struct super_block *sb, void *data, int silent) if (!sb->s_root) return -ENOMEM; - return binderfs_binder_ctl_create(sb); + ret = binderfs_binder_ctl_create(sb); + if (ret) + return ret; + + name = binder_devices_param; + for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { + strscpy(device_info.name, name, len + 1); + ret = binderfs_binder_device_create(inode, NULL, &device_info); + if (ret) + return ret; + name += len; + if (*name == ',') + name++; + } + + return 0; } static struct dentry *binderfs_mount(struct file_system_type *fs_type, -- cgit v1.2.3