From e8dd273d199f5bbe295a8e3d8b777c5505b6b2e1 Mon Sep 17 00:00:00 2001 From: Salah Triki Date: Thu, 17 Sep 2026 14:00:52 +0100 Subject: iio: proximity: isl29501: Fix return type of isl29501_register_write isl29501_register_write() was returning a u32 instead of an int. Since the function returns negative error codes (such as -ERANGE or return values from i2c_smbus_write_byte_data()), returning an unsigned integer type prevents callers from correctly checking for negative error conditions. Fix this by changing the function return type from u32 to int. This was found through manual code review. Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.") Signed-off-by: Salah Triki Reviewed-by: Joshua Crofts Cc: stable@vger.kernel.org Signed-off-by: Jonathan Cameron --- drivers/android/binder/context.rs | 175 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 drivers/android/binder/context.rs (limited to 'drivers/android/binder/context.rs') diff --git a/drivers/android/binder/context.rs b/drivers/android/binder/context.rs new file mode 100644 index 000000000..ddddb66b3 --- /dev/null +++ b/drivers/android/binder/context.rs @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2025 Google LLC. + +use kernel::{ + alloc::kvec::KVVec, + error::code::*, + prelude::*, + security, + str::{CStr, CString}, + sync::{Arc, Mutex}, + task::Kuid, +}; + +use crate::{error::BinderError, node::NodeRef, process::Process}; + +kernel::sync::global_lock! { + // SAFETY: We call `init` in the module initializer, so it's initialized before first use. + pub(crate) unsafe(uninit) static CONTEXTS: Mutex = ContextList { + contexts: KVVec::new(), + }; +} + +pub(crate) struct ContextList { + contexts: KVVec>, +} + +pub(crate) fn get_all_contexts() -> Result>> { + let lock = CONTEXTS.lock(); + let mut ctxs = KVVec::with_capacity(lock.contexts.len(), GFP_KERNEL)?; + for ctx in lock.contexts.iter() { + ctxs.push(ctx.clone(), GFP_KERNEL)?; + } + Ok(ctxs) +} + +/// This struct keeps track of the processes using this context, and which process is the context +/// manager. +struct Manager { + node: Option, + uid: Option, + all_procs: KVVec>, +} + +/// There is one context per binder file (/dev/binder, /dev/hwbinder, etc) +#[pin_data] +pub(crate) struct Context { + #[pin] + manager: Mutex, + pub(crate) name: CString, +} + +impl Context { + pub(crate) fn new(name: &CStr) -> Result> { + let name = CString::try_from(name)?; + let ctx = Arc::pin_init( + try_pin_init!(Context { + name, + manager <- kernel::new_mutex!(Manager { + all_procs: KVVec::new(), + node: None, + uid: None, + }, "Context::manager"), + }), + GFP_KERNEL, + )?; + + CONTEXTS.lock().contexts.push(ctx.clone(), GFP_KERNEL)?; + + Ok(ctx) + } + + /// Called when the file for this context is unlinked. + /// + /// No-op if called twice. + pub(crate) fn deregister(self: &Arc) { + // Safe removal using retain + CONTEXTS.lock().contexts.retain(|c| !Arc::ptr_eq(c, self)); + } + + pub(crate) fn register_process(self: &Arc, proc: Arc) -> Result { + if !Arc::ptr_eq(self, &proc.ctx) { + pr_err!("Context::register_process called on the wrong context."); + return Err(EINVAL); + } + self.manager.lock().all_procs.push(proc, GFP_KERNEL)?; + Ok(()) + } + + pub(crate) fn deregister_process(self: &Arc, proc: &Arc) { + if !Arc::ptr_eq(self, &proc.ctx) { + pr_err!("Context::deregister_process called on the wrong context."); + return; + } + let mut manager = self.manager.lock(); + manager.all_procs.retain(|p| !Arc::ptr_eq(p, proc)); + + // Shrink the vector if it has significant unused capacity to avoid memory waste, + // but use a conservative strategy to prevent shrink-then-regrow oscillation. + // Only shrink when length drops below 1/4 of capacity, and shrink to twice the length. + let len = manager.all_procs.len(); + let cap = manager.all_procs.capacity(); + if len < cap / 4 { + // Shrink to twice the current length. Ignore allocation failures since this + // is just an optimization; the vector remains valid even if shrinking fails. + let _ = manager.all_procs.shrink_to(len * 2, GFP_KERNEL); + } + } + + pub(crate) fn set_manager_node(&self, node_ref: NodeRef) -> Result { + let mut manager = self.manager.lock(); + if manager.node.is_some() { + pr_warn!("BINDER_SET_CONTEXT_MGR already set"); + return Err(EBUSY); + } + security::binder_set_context_mgr(&node_ref.node.owner.cred)?; + + // If the context manager has been set before, ensure that we use the same euid. + let caller_uid = Kuid::current_euid(); + if let Some(ref uid) = manager.uid { + if *uid != caller_uid { + return Err(EPERM); + } + } + + manager.node = Some(node_ref); + manager.uid = Some(caller_uid); + Ok(()) + } + + pub(crate) fn unset_manager_node(&self) { + let node_ref = self.manager.lock().node.take(); + drop(node_ref); + } + + pub(crate) fn get_manager_node(&self, strong: bool) -> Result { + self.manager + .lock() + .node + .as_ref() + .ok_or_else(BinderError::new_dead)? + .clone(strong) + .map_err(BinderError::from) + } + + pub(crate) fn for_each_proc(&self, mut func: F) + where + F: FnMut(&Process), + { + let lock = self.manager.lock(); + for proc in &lock.all_procs { + func(proc); + } + } + + pub(crate) fn get_all_procs(&self) -> Result>> { + let lock = self.manager.lock(); + let mut procs = KVVec::with_capacity(lock.all_procs.len(), GFP_KERNEL)?; + for proc in lock.all_procs.iter() { + procs.push(Arc::clone(proc), GFP_KERNEL)?; + } + Ok(procs) + } + + pub(crate) fn get_procs_with_pid(&self, pid: i32) -> Result>> { + let lock = self.manager.lock(); + let mut matching_procs = KVVec::new(); + for proc in lock.all_procs.iter() { + if proc.task.pid() == pid { + matching_procs.push(Arc::clone(proc), GFP_KERNEL)?; + } + } + Ok(matching_procs) + } +} -- cgit v1.3.1