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https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-08-28 08:44:29 -04:00
2847d9ab08
Implement a dynamic debug logging mask (`debug_mask`) for the `rust_binder` module to allow dynamic runtime configuration of log levels. This enables parity with the legacy C driver's debug mask. Since the Rust `module!` macro in the current kernel build does not yet support declaring module parameters directly in Rust, we define the `debug_mask` variable in Rust as an `Atomic<u32>` exported via FFI using `#[no_mangle]`, and link to it as `extern` in a C companion file to expose it to the kernel runtime. To verify the setup, instrument process lifecycle events (open, flush, and release) in `process.rs` under the new `BINDER_DEBUG_OPEN_CLOSE` logging mask. These entry-point events are chosen for initial validation because they represent the start of the Binder lifecycle and occur at low frequency, allowing simple runtime verification of the dynamic toggle without log noise. Reviewed-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Jahnavi MN <jahnavimn@google.com> Link: https://patch.msgid.link/20260716-rust_binder_debug_mask-v4-1-3d7436c2d2f2@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
77 lines
2.3 KiB
Rust
77 lines
2.3 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2026 Google LLC.
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//! Binder debugging helpers.
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#![allow(dead_code)]
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use kernel::bits::bit_u32;
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use kernel::sync::atomic::Atomic;
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kernel::impl_flags!(
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/// Represents multiple debug mask flags.
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#[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
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pub struct DebugMasks(u32);
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/// Represents a single debug mask category.
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub enum DebugMask {
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UserError = bit_u32(0),
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FailedTransaction = bit_u32(1),
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DeadTransaction = bit_u32(2),
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OpenClose = bit_u32(3),
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DeadBinder = bit_u32(4),
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DeathNotification = bit_u32(5),
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ReadWrite = bit_u32(6),
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UserRefs = bit_u32(7),
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Threads = bit_u32(8),
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Transaction = bit_u32(9),
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TransactionComplete = bit_u32(10),
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FreeBuffer = bit_u32(11),
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InternalRefs = bit_u32(12),
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PriorityCap = bit_u32(13),
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Spinlocks = bit_u32(14),
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}
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);
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#[no_mangle]
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pub(crate) static rust_binder_debug_mask: Atomic<u32> = Atomic::new(
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(DebugMask::UserError as u32)
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| (DebugMask::FailedTransaction as u32)
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| (DebugMask::DeadTransaction as u32),
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);
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/// Checks if the given debug logging category is enabled in the mask.
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pub(crate) fn debug_mask_enabled(mask: DebugMask) -> bool {
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let current_mask = rust_binder_debug_mask.load(kernel::sync::atomic::Relaxed);
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DebugMasks(current_mask).contains(mask)
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}
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/// Prints a debug log if the specified mask category is enabled.
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#[macro_export]
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macro_rules! binder_debug {
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// Rule to explicitly specify a PID (used in kworkers).
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(pid=$pid:expr, $mask:ident, $($arg:tt)*) => {
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if $crate::debug::debug_mask_enabled($crate::debug::DebugMask::$mask) {
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kernel::pr_info!(
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"{}: {}\n",
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$pid,
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kernel::prelude::fmt!($($arg)*)
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);
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}
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};
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// Default rule (automatically prepends "PID:TID" of the current calling thread).
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($mask:ident, $($arg:tt)*) => {
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if $crate::debug::debug_mask_enabled($crate::debug::DebugMask::$mask) {
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let thread = kernel::current!();
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kernel::pr_info!(
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"{}:{} {}\n",
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thread.tgid(),
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thread.pid(),
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kernel::prelude::fmt!($($arg)*)
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);
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}
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};
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}
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