From feba3900cabb8e7c87368faa28e7a6936809ba22 Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Fri, 3 Feb 2017 14:40:45 -0800 Subject: binder: Split flat_binder_object MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit flat_binder_object is used for both handling binder objects and file descriptors, even though the two are mostly independent. Since we'll have more fixup objects in binder in the future, instead of extending flat_binder_object again, split out file descriptors to their own object while retaining backwards compatibility to existing user-space clients. All binder objects just share a header. Cc: Greg Kroah-Hartman Cc: Martijn Coenen Cc: Arve Hjønnevåg Cc: Amit Pundir Cc: Serban Constantinescu Cc: Dmitry Shmidt Cc: Rom Lemarchand Cc: Android Kernel Team Signed-off-by: Martijn Coenen Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/android/binder.h | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) (limited to 'include/uapi/linux/android') diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index 41420e341e75..f67c2b1c0713 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -48,6 +48,14 @@ typedef __u64 binder_size_t; typedef __u64 binder_uintptr_t; #endif +/** + * struct binder_object_header - header shared by all binder metadata objects. + * @type: type of the object + */ +struct binder_object_header { + __u32 type; +}; + /* * This is the flattened representation of a Binder object for transfer * between processes. The 'offsets' supplied as part of a binder transaction @@ -56,9 +64,8 @@ typedef __u64 binder_uintptr_t; * between processes. */ struct flat_binder_object { - /* 8 bytes for large_flat_header. */ - __u32 type; - __u32 flags; + struct binder_object_header hdr; + __u32 flags; /* 8 bytes of data. */ union { @@ -70,6 +77,24 @@ struct flat_binder_object { binder_uintptr_t cookie; }; +/** + * struct binder_fd_object - describes a filedescriptor to be fixed up. + * @hdr: common header structure + * @pad_flags: padding to remain compatible with old userspace code + * @pad_binder: padding to remain compatible with old userspace code + * @fd: file descriptor + * @cookie: opaque data, used by user-space + */ +struct binder_fd_object { + struct binder_object_header hdr; + __u32 pad_flags; + union { + binder_uintptr_t pad_binder; + __u32 fd; + }; + + binder_uintptr_t cookie; +}; /* * On 64-bit platforms where user code may run in 32-bits the driver must * translate the buffer (and local binder) addresses appropriately. -- cgit v1.2.3 From 7980240b6d63e0694f5023c29cbc648fafdf3e23 Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Fri, 3 Feb 2017 14:40:51 -0800 Subject: binder: Add support for scatter-gather MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Previously all data passed over binder needed to be serialized, with the exception of Binder objects and file descriptors. This patchs adds support for scatter-gathering raw memory buffers into a binder transaction, avoiding the need to first serialize them into a Parcel. To remain backwards compatibile with existing binder clients, it introduces two new command ioctls for this purpose - BC_TRANSACTION_SG and BC_REPLY_SG. These commands may only be used with the new binder_transaction_data_sg structure, which adds a field for the total size of the buffers we are scatter-gathering. Because memory buffers may contain pointers to other buffers, we allow callers to specify a parent buffer and an offset into it, to indicate this is a location pointing to the buffer that we are fixing up. The kernel will then take care of fixing up the pointer to that buffer as well. Cc: Greg Kroah-Hartman Cc: Martijn Coenen Cc: Arve Hjønnevåg Cc: Amit Pundir Cc: Serban Constantinescu Cc: Dmitry Shmidt Cc: Rom Lemarchand Cc: Android Kernel Team Signed-off-by: Martijn Coenen [jstultz: Fold in small fix from Amit Pundir ] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/android/binder.h | 45 +++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'include/uapi/linux/android') diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index f67c2b1c0713..f3ef6e2634ba 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -33,6 +33,7 @@ enum { BINDER_TYPE_HANDLE = B_PACK_CHARS('s', 'h', '*', B_TYPE_LARGE), BINDER_TYPE_WEAK_HANDLE = B_PACK_CHARS('w', 'h', '*', B_TYPE_LARGE), BINDER_TYPE_FD = B_PACK_CHARS('f', 'd', '*', B_TYPE_LARGE), + BINDER_TYPE_PTR = B_PACK_CHARS('p', 't', '*', B_TYPE_LARGE), }; enum { @@ -95,6 +96,39 @@ struct binder_fd_object { binder_uintptr_t cookie; }; + +/* struct binder_buffer_object - object describing a userspace buffer + * @hdr: common header structure + * @flags: one or more BINDER_BUFFER_* flags + * @buffer: address of the buffer + * @length: length of the buffer + * @parent: index in offset array pointing to parent buffer + * @parent_offset: offset in @parent pointing to this buffer + * + * A binder_buffer object represents an object that the + * binder kernel driver can copy verbatim to the target + * address space. A buffer itself may be pointed to from + * within another buffer, meaning that the pointer inside + * that other buffer needs to be fixed up as well. This + * can be done by setting the BINDER_BUFFER_FLAG_HAS_PARENT + * flag in @flags, by setting @parent buffer to the index + * in the offset array pointing to the parent binder_buffer_object, + * and by setting @parent_offset to the offset in the parent buffer + * at which the pointer to this buffer is located. + */ +struct binder_buffer_object { + struct binder_object_header hdr; + __u32 flags; + binder_uintptr_t buffer; + binder_size_t length; + binder_size_t parent; + binder_size_t parent_offset; +}; + +enum { + BINDER_BUFFER_FLAG_HAS_PARENT = 0x01, +}; + /* * On 64-bit platforms where user code may run in 32-bits the driver must * translate the buffer (and local binder) addresses appropriately. @@ -187,6 +221,11 @@ struct binder_transaction_data { } data; }; +struct binder_transaction_data_sg { + struct binder_transaction_data transaction_data; + binder_size_t buffers_size; +}; + struct binder_ptr_cookie { binder_uintptr_t ptr; binder_uintptr_t cookie; @@ -371,6 +410,12 @@ enum binder_driver_command_protocol { /* * void *: cookie */ + + BC_TRANSACTION_SG = _IOW('c', 17, struct binder_transaction_data_sg), + BC_REPLY_SG = _IOW('c', 18, struct binder_transaction_data_sg), + /* + * binder_transaction_data_sg: the sent command. + */ }; #endif /* _UAPI_LINUX_BINDER_H */ -- cgit v1.2.3 From def95c73567dfacb22900cd0c4f01caff39e4c9e Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Fri, 3 Feb 2017 14:40:52 -0800 Subject: binder: Add support for file-descriptor arrays MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch introduces a new binder_fd_array object, that allows us to support one or more file descriptors embedded in a buffer that is scatter-gathered. Cc: Greg Kroah-Hartman Cc: Martijn Coenen Cc: Arve Hjønnevåg Cc: Amit Pundir Cc: Serban Constantinescu Cc: Dmitry Shmidt Cc: Rom Lemarchand Cc: Android Kernel Team Signed-off-by: Martijn Coenen Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/android/binder.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'include/uapi/linux/android') diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index f3ef6e2634ba..51f891fb1b18 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -33,6 +33,7 @@ enum { BINDER_TYPE_HANDLE = B_PACK_CHARS('s', 'h', '*', B_TYPE_LARGE), BINDER_TYPE_WEAK_HANDLE = B_PACK_CHARS('w', 'h', '*', B_TYPE_LARGE), BINDER_TYPE_FD = B_PACK_CHARS('f', 'd', '*', B_TYPE_LARGE), + BINDER_TYPE_FDA = B_PACK_CHARS('f', 'd', 'a', B_TYPE_LARGE), BINDER_TYPE_PTR = B_PACK_CHARS('p', 't', '*', B_TYPE_LARGE), }; @@ -129,6 +130,33 @@ enum { BINDER_BUFFER_FLAG_HAS_PARENT = 0x01, }; +/* struct binder_fd_array_object - object describing an array of fds in a buffer + * @hdr: common header structure + * @num_fds: number of file descriptors in the buffer + * @parent: index in offset array to buffer holding the fd array + * @parent_offset: start offset of fd array in the buffer + * + * A binder_fd_array object represents an array of file + * descriptors embedded in a binder_buffer_object. It is + * different from a regular binder_buffer_object because it + * describes a list of file descriptors to fix up, not an opaque + * blob of memory, and hence the kernel needs to treat it differently. + * + * An example of how this would be used is with Android's + * native_handle_t object, which is a struct with a list of integers + * and a list of file descriptors. The native_handle_t struct itself + * will be represented by a struct binder_buffer_objct, whereas the + * embedded list of file descriptors is represented by a + * struct binder_fd_array_object with that binder_buffer_object as + * a parent. + */ +struct binder_fd_array_object { + struct binder_object_header hdr; + binder_size_t num_fds; + binder_size_t parent; + binder_size_t parent_offset; +}; + /* * On 64-bit platforms where user code may run in 32-bits the driver must * translate the buffer (and local binder) addresses appropriately. -- cgit v1.2.3