// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2025 Google LLC.
//! This module defines the `Thread` type, which represents a userspace thread that is using
//! binder.
//!
//! The `Process` object stores all of the threads in an rb tree.
use kernel::{
bindings,
fs::{File, LocalFile},
list::{AtomicTracker, List, ListArc, ListLinks, TryNewListArc},
prelude::*,
security,
seq_file::SeqFile,
seq_print,
sync::atomic::{ordering::Relaxed, Atomic},
sync::poll::{PollCondVar, PollTable},
sync::{aref::ARef, Arc, SpinLock},
task::Task,
uaccess::{UserPtr, UserSlice, UserSliceReader},
uapi,
};
use crate::{
allocation::{Allocation, AllocationView, BinderObject, BinderObjectRef, NewAllocation},
defs::*,
error::BinderResult,
process::{GetWorkOrRegister, Process},
ptr_align,
stats::GLOBAL_STATS,
transaction::{Transaction, TransactionInfo},
BinderReturnWriter, DArc, DLArc, DTRWrap, DeliverCode, DeliverToRead,
};
use core::mem::size_of;
fn is_aligned(value: usize, to: usize) -> bool {
value % to == 0
}
/// Stores the layout of the scatter-gather entries. This is used during the `translate_objects`
/// call and is discarded when it returns.
struct ScatterGatherState {
/// A struct that tracks the amount of unused buffer space.
unused_buffer_space: UnusedBufferSpace,
/// Scatter-gather entries to copy.
sg_entries: KVec<ScatterGatherEntry>,
/// Indexes into `sg_entries` corresponding to the last binder_buffer_object that
/// was processed and all of its ancestors. The array is in sorted order.
ancestors: KVec<usize>,
}
/// This entry specifies an additional buffer that should be copied using the scatter-gather
/// mechanism.
struct ScatterGatherEntry {
/// The index in the offset array of the BINDER_TYPE_PTR that this entry originates from.
obj_index: usize,
/// Offset in target buffer.
offset: usize,
/// User address in source buffer.
sender_uaddr: usize,
/// Number of bytes to copy.
length: usize,
/// The minimum offset of the next fixup in this buffer.
fixup_min_offset: usize,
/// The offsets within this buffer that contain pointers which should be translated.
pointer_fixups: KVec<PointerFixupEntry>,
}
/// This entry specifies that a fixup should happen at `target_offset` of the
/// buffer.
enum PointerFixupEntry {
/// A fixup for a `binder_buffer_object`.
Fixup {
/// The translated pointer to write.
pointer_value: u64,
/// The offset at which the value should be written. The offset is relativ
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