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/trace.rs | 107 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 drivers/android/binder/trace.rs (limited to 'drivers/android/binder/trace.rs') diff --git a/drivers/android/binder/trace.rs b/drivers/android/binder/trace.rs new file mode 100644 index 000000000..06aabb3cc --- /dev/null +++ b/drivers/android/binder/trace.rs @@ -0,0 +1,107 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2025 Google LLC. + +use crate::transaction::Transaction; + +use core::ptr; + +use kernel::bindings::{rust_binder_transaction, task_struct}; +use kernel::error::Result; +use kernel::ffi::{c_int, c_uint, c_ulong}; +use kernel::task::Task; +use kernel::tracepoint::declare_trace; + +declare_trace! { + unsafe fn binder_ioctl(cmd: c_uint, arg: c_ulong); + unsafe fn binder_ioctl_done(ret: c_int); + unsafe fn binder_read_done(ret: c_int); + unsafe fn binder_write_done(ret: c_int); + unsafe fn binder_wait_for_work(proc_work: bool, transaction_stack: bool, thread_todo: bool); + unsafe fn binder_transaction(reply: bool, t: rust_binder_transaction, thread: *mut task_struct); + unsafe fn binder_transaction_received(t: rust_binder_transaction); + unsafe fn binder_transaction_fd_send(t_debug_id: c_int, fd: c_int, offset: usize); + unsafe fn binder_transaction_fd_recv(t_debug_id: c_int, fd: c_int, offset: usize); + unsafe fn binder_command(cmd: u32); + unsafe fn binder_return(ret: u32); +} + +#[inline] +fn raw_transaction(t: &Transaction) -> rust_binder_transaction { + ptr::from_ref(t).cast_mut().cast() +} + +#[inline] +fn to_errno(ret: Result) -> i32 { + match ret { + Ok(()) => 0, + Err(err) => err.to_errno(), + } +} + +#[inline] +pub(crate) fn trace_ioctl(cmd: u32, arg: usize) { + // SAFETY: Always safe to call. + unsafe { binder_ioctl(cmd, arg as c_ulong) } +} + +#[inline] +pub(crate) fn trace_ioctl_done(ret: Result) { + // SAFETY: Always safe to call. + unsafe { binder_ioctl_done(to_errno(ret)) } +} +#[inline] +pub(crate) fn trace_read_done(ret: Result) { + // SAFETY: Always safe to call. + unsafe { binder_read_done(to_errno(ret)) } +} +#[inline] +pub(crate) fn trace_write_done(ret: Result) { + // SAFETY: Always safe to call. + unsafe { binder_write_done(to_errno(ret)) } +} + +#[inline] +pub(crate) fn trace_wait_for_work(proc_work: bool, transaction_stack: bool, thread_todo: bool) { + // SAFETY: Always safe to call. + unsafe { binder_wait_for_work(proc_work, transaction_stack, thread_todo) } +} + +#[inline] +pub(crate) fn trace_transaction(reply: bool, t: &Transaction, thread: Option<&Task>) { + let thread = match thread { + Some(thread) => thread.as_ptr(), + None => core::ptr::null_mut(), + }; + // SAFETY: The raw transaction is valid for the duration of this call. The thread pointer is + // valid or null. + unsafe { binder_transaction(reply, raw_transaction(t), thread) } +} + +#[inline] +pub(crate) fn trace_transaction_received(t: &Transaction) { + // SAFETY: The raw transaction is valid for the duration of this call. + unsafe { binder_transaction_received(raw_transaction(t)) } +} + +#[inline] +pub(crate) fn trace_transaction_fd_send(t_debug_id: usize, fd: u32, offset: usize) { + // SAFETY: This function is always safe to call. + unsafe { binder_transaction_fd_send(t_debug_id as c_int, fd as c_int, offset) } +} +#[inline] +pub(crate) fn trace_transaction_fd_recv(t_debug_id: usize, fd: u32, offset: usize) { + // SAFETY: This function is always safe to call. + unsafe { binder_transaction_fd_recv(t_debug_id as c_int, fd as c_int, offset) } +} + +#[inline] +pub(crate) fn trace_command(cmd: u32) { + // SAFETY: This function is always safe to call. + unsafe { binder_command(cmd) } +} +#[inline] +pub(crate) fn trace_return(ret: u32) { + // SAFETY: This function is always safe to call. + unsafe { binder_return(ret) } +} -- cgit v1.3.1