From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/android/binder/defs.rs | 184 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 drivers/android/binder/defs.rs (limited to 'drivers/android/binder/defs.rs') diff --git a/drivers/android/binder/defs.rs b/drivers/android/binder/defs.rs new file mode 100644 index 000000000..8ac9bdd7a --- /dev/null +++ b/drivers/android/binder/defs.rs @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2025 Google LLC. + +use core::mem::MaybeUninit; +use core::ops::{Deref, DerefMut}; +use core::ptr; + +use kernel::{ + transmute::{AsBytes, FromBytes}, + uapi::{self, *}, +}; + +macro_rules! pub_no_prefix { + ($prefix:ident, $($newname:ident),+ $(,)?) => { + $(pub(crate) const $newname: u32 = kernel::macros::concat_idents!($prefix, $newname);)+ + }; +} + +pub_no_prefix!( + binder_driver_return_protocol_, + BR_TRANSACTION, + BR_TRANSACTION_SEC_CTX, + BR_REPLY, + BR_DEAD_REPLY, + BR_FAILED_REPLY, + BR_FROZEN_REPLY, + BR_NOOP, + BR_SPAWN_LOOPER, + BR_TRANSACTION_COMPLETE, + BR_TRANSACTION_PENDING_FROZEN, + BR_ONEWAY_SPAM_SUSPECT, + BR_OK, + BR_ERROR, + BR_INCREFS, + BR_ACQUIRE, + BR_RELEASE, + BR_DECREFS, + BR_DEAD_BINDER, + BR_CLEAR_DEATH_NOTIFICATION_DONE, + BR_FROZEN_BINDER, + BR_CLEAR_FREEZE_NOTIFICATION_DONE, +); + +pub_no_prefix!( + binder_driver_command_protocol_, + BC_TRANSACTION, + BC_TRANSACTION_SG, + BC_REPLY, + BC_REPLY_SG, + BC_FREE_BUFFER, + BC_ENTER_LOOPER, + BC_EXIT_LOOPER, + BC_REGISTER_LOOPER, + BC_INCREFS, + BC_ACQUIRE, + BC_RELEASE, + BC_DECREFS, + BC_INCREFS_DONE, + BC_ACQUIRE_DONE, + BC_REQUEST_DEATH_NOTIFICATION, + BC_CLEAR_DEATH_NOTIFICATION, + BC_DEAD_BINDER_DONE, + BC_REQUEST_FREEZE_NOTIFICATION, + BC_CLEAR_FREEZE_NOTIFICATION, + BC_FREEZE_NOTIFICATION_DONE, +); + +pub_no_prefix!( + flat_binder_object_flags_, + FLAT_BINDER_FLAG_ACCEPTS_FDS, + FLAT_BINDER_FLAG_TXN_SECURITY_CTX +); + +pub_no_prefix!( + transaction_flags_, + TF_ONE_WAY, + TF_ACCEPT_FDS, + TF_CLEAR_BUF, + TF_UPDATE_TXN +); + +pub(crate) use uapi::{ + BINDER_TYPE_BINDER, BINDER_TYPE_FD, BINDER_TYPE_FDA, BINDER_TYPE_HANDLE, BINDER_TYPE_PTR, + BINDER_TYPE_WEAK_BINDER, BINDER_TYPE_WEAK_HANDLE, +}; + +macro_rules! decl_wrapper { + ($newname:ident, $wrapped:ty) => { + // Define a wrapper around the C type. Use `MaybeUninit` to enforce that the value of + // padding bytes must be preserved. + #[derive(Copy, Clone)] + #[repr(transparent)] + pub(crate) struct $newname(MaybeUninit<$wrapped>); + + // SAFETY: This macro is only used with types where this is ok. + unsafe impl FromBytes for $newname {} + // SAFETY: This macro is only used with types where this is ok. + unsafe impl AsBytes for $newname {} + + impl Deref for $newname { + type Target = $wrapped; + fn deref(&self) -> &Self::Target { + // SAFETY: We use `MaybeUninit` only to preserve padding. The value must still + // always be valid. + unsafe { self.0.assume_init_ref() } + } + } + + impl DerefMut for $newname { + fn deref_mut(&mut self) -> &mut Self::Target { + // SAFETY: We use `MaybeUninit` only to preserve padding. The value must still + // always be valid. + unsafe { self.0.assume_init_mut() } + } + } + + impl Default for $newname { + fn default() -> Self { + // Create a new value of this type where all bytes (including padding) are zeroed. + Self(MaybeUninit::zeroed()) + } + } + }; +} + +decl_wrapper!(BinderNodeDebugInfo, uapi::binder_node_debug_info); +decl_wrapper!(BinderNodeInfoForRef, uapi::binder_node_info_for_ref); +decl_wrapper!(FlatBinderObject, uapi::flat_binder_object); +decl_wrapper!(BinderFdObject, uapi::binder_fd_object); +decl_wrapper!(BinderFdArrayObject, uapi::binder_fd_array_object); +decl_wrapper!(BinderObjectHeader, uapi::binder_object_header); +decl_wrapper!(BinderBufferObject, uapi::binder_buffer_object); +decl_wrapper!(BinderTransactionData, uapi::binder_transaction_data); +decl_wrapper!( + BinderTransactionDataSecctx, + uapi::binder_transaction_data_secctx +); +decl_wrapper!(BinderTransactionDataSg, uapi::binder_transaction_data_sg); +decl_wrapper!(BinderWriteRead, uapi::binder_write_read); +decl_wrapper!(BinderVersion, uapi::binder_version); +decl_wrapper!(BinderFrozenStatusInfo, uapi::binder_frozen_status_info); +decl_wrapper!(BinderFreezeInfo, uapi::binder_freeze_info); +decl_wrapper!(BinderFrozenStateInfo, uapi::binder_frozen_state_info); +decl_wrapper!(BinderHandleCookie, uapi::binder_handle_cookie); +decl_wrapper!(ExtendedError, uapi::binder_extended_error); + +impl BinderVersion { + pub(crate) fn current() -> Self { + Self(MaybeUninit::new(uapi::binder_version { + protocol_version: BINDER_CURRENT_PROTOCOL_VERSION as i32, + })) + } +} + +impl BinderTransactionData { + pub(crate) fn with_buffers_size(self, buffers_size: u64) -> BinderTransactionDataSg { + BinderTransactionDataSg(MaybeUninit::new(uapi::binder_transaction_data_sg { + transaction_data: *self, + buffers_size, + })) + } +} + +impl BinderTransactionDataSecctx { + /// View the inner data as wrapped in `BinderTransactionData`. + pub(crate) fn tr_data(&mut self) -> &mut BinderTransactionData { + // SAFETY: Transparent wrapper is safe to transmute. + unsafe { + &mut *(ptr::from_mut::(&mut self.transaction_data) + .cast::()) + } + } +} + +impl ExtendedError { + pub(crate) fn new(id: u32, command: u32, param: i32) -> Self { + Self(MaybeUninit::new(uapi::binder_extended_error { + id, + command, + param, + })) + } +} -- cgit v1.3.1