Merge upstream/master into submodule/kernel

Sync the kernel fork with 10 upstream commits (context timer-separation
with unblock_context/wakeup_context, dtb MMIO/bus-address translation
+ tests, event read_with_timeout support, proc wakeup paths, dup2
rewrite with rollback, futex Weak context_lock + unblock_context,
memory/init ordering, and more). Satisfies the verify-fork-functions
gate (11 previously-missing upstream functions now present).

Conflicts resolved (5 files; 9 auto-merged):

- src/syscall/futex.rs: took upstream's version wholesale (Weak
  context_lock, upgrade+unblock_context, TimeSpec::to_nanos,
  get_futex_stat, addr_space strong_count cleanup); re-applied the RB
  FUTEX_WAIT_MULTIPLE/FUTEX_REQUEUE implementations adapted to the
  Weak API, with wake-index bookkeeping preserved
  (Context::futex_wake_index survives in context.rs).

- src/event.rs: merged EventQueue with both RB's fd-refcount refs and
  upstream's timeout_opt (init in new()); kept RB's EventCounter/
  eventfd block; added upstream's read_with_timeout +
  EVENT_TIMEOUT_ID write handling; deduplicated EAGAIN/EINTR imports.

- src/scheme/proc.rs: upstream imports minus UnmapVec (RB deleted that
  machinery from context/memory.rs — import-only dependency);
  ContextHandle::Start keeps RB's require_zero_offset + upstream's
  wakeup_context; FORCEKILL region takes upstream's
  is_dead()/being_sigkilled form.

- src/syscall/fs.rs: took upstream's dup2 structure (natural
  self-dup-with-buf handling — preserves the relibc dup2(ft,ft,
  "refresh") semantic — plus rollback on insert failure), adapted to
  the fork's 4-arg duplicate_file and read/token_split conventions.

- src/arch/aarch64/start.rs: kept upstream's new PageMapper/
  acpi::init_before_mem/memory::init_mm init block.

Verified: repo cook kernel --force-rebuild successful;
verify-fork-functions.sh --no-fetch kernel passes.

.gitignore

@@ -1,3 +1,5 @@
 target
+/build
 /config.toml
+/sysroot
 .gitlab-ci-local/

.gitlab-ci.yml

@@ -1,8 +1,3 @@
-image: "redoxos/redoxer:latest"
-
-variables:
-  GIT_SUBMODULE_STRATEGY: recursive
-
 workflow:
   rules:
     - if: '$CI_PROJECT_NAMESPACE == "redox-os"'
@@ -12,14 +7,12 @@ stages:
   - build
   - cross-build
   - test
-  - other-features
   # TODO: benchmarks and profiling (maybe manually enabled for relevant MRs)?
 
 x86_64:
   stage: build
   script:
-    - mkdir -p target/${ARCH}
+    - redoxer env make
-    - redoxer env make BUILD=target/${ARCH}
   variables:
     ARCH: "x86_64"
 
@@ -27,64 +20,50 @@ aarch64:
   stage: cross-build
   image: "redoxos/redoxer:aarch64"
   script:
-    - mkdir -p target/${ARCH}
+    - redoxer env make
-    - redoxer env make BUILD=target/${ARCH}
   variables:
     ARCH: "aarch64"
 
 i586:
   stage: cross-build
   script:
-    - mkdir -p target/${ARCH}
+    - TARGET=${ARCH}-unknown-redox redoxer env make
-    - TARGET=${ARCH}-unknown-redox redoxer env make BUILD=target/${ARCH}
   variables:
     ARCH: "i586"
 
 riscv64gc:
   stage: cross-build
   script:
-    - mkdir -p target/${ARCH}
+    - TARGET=${ARCH}-unknown-redox redoxer env make
-    - TARGET=${ARCH}-unknown-redox redoxer env make BUILD=target/${ARCH}
   variables:
     ARCH: "riscv64gc"
 
 fmt:
   stage: build
   script:
-      - rustup component add rustfmt
+      - redoxer env cargo fmt --check
-      - rustfmt --check
 
 x86_64:boot:
   stage: test
   needs: [x86_64]
   script:
-    - mkdir -p target/${ARCH}
     - export COOKBOOK_SOURCE_IDENT=$CI_COMMIT_SHA
-    - redoxer env make BUILD=target/${ARCH}
+    - redoxer env make test
-    - timeout -s KILL 9m redoxer exec --folder target/${ARCH}/:/usr/lib/boot uname -a
-  variables:
-    ARCH: "x86_64"
 
 x86_64:relibc:
   stage: test
   needs: [x86_64]
+  # TODO: remove
+  allow_failure: true
   script:
-    - redoxer pkg relibc-tests-bins
     - export COOKBOOK_SOURCE_IDENT=$CI_COMMIT_SHA
-    - mkdir -p target/${TARGET}/sysroot/{usr/lib/boot,root} target/${TARGET}/root
+    - timeout -s KILL 9m redoxer env make test-relibc
-    - redoxer env make BUILD=target/${TARGET}/sysroot/usr/lib/boot
-    - (cd target/${TARGET}/sysroot && mv home/user/relibc-tests/* root/)
-    - timeout -s KILL 9m redoxer exec --folder target/${TARGET}/sysroot/:/ make run
-  # It is fine if failing sometimes
-  allow_failure: true
-  variables:
-    TARGET: "x86_64-unknown-redox"
 
-profiling-compile:
+x86_64:profiling:
-  stage: other-features
+  stage: build
-  allow_failure: true
+  needs: [x86_64]
   script:
-    make check
+  - make check
   variables:
     ARCH: "x86_64"
     KERNEL_CHECK_FEATURES: profiling

Makefile

@@ -2,7 +2,6 @@
 .PHONY: all check
 
 SOURCE:=$(dir $(realpath $(lastword $(MAKEFILE_LIST))))
-BUILD?=$(CURDIR)
 export RUST_TARGET_PATH=$(SOURCE)/targets
 
 ifeq ($(TARGET),)
@@ -11,6 +10,9 @@ else
 	ARCH?=$(shell echo "$(TARGET)" | cut -d - -f1)
 endif
 
+BUILD?=$(CURDIR)/build/$(ARCH)
+DESTDIR?=./sysroot
+
 ifeq ($(ARCH),riscv64gc)
 	override ARCH:=riscv64
 	GNU_TARGET=riscv64-unknown-redox
@@ -21,6 +23,7 @@ else
 	GNU_TARGET=$(ARCH)-unknown-redox
 endif
 
+OBJCOPY?=$(GNU_TARGET)-objcopy
 
 all: $(BUILD)/kernel $(BUILD)/kernel.sym
 
@@ -31,7 +34,10 @@ TARGET_SPEC=$(RUST_TARGET_PATH)/$(ARCH)-unknown-kernel.json
 
 KERNEL_CARGO_FEATURES?=
 
-$(BUILD)/kernel.all: $(LD_SCRIPT) $(LOCKFILE) $(MANIFEST) $(TARGET_SPEC) $(shell find $(SOURCE) -name "*.rs" -type f)
+$(BUILD):
+	mkdir -p "$@"
+
+$(BUILD)/kernel.all: $(LD_SCRIPT) $(LOCKFILE) $(MANIFEST) $(TARGET_SPEC) $(shell find $(SOURCE) -name "*.rs" -type f) | $(BUILD)
 	cargo rustc \
 		--bin kernel \
 		--manifest-path "$(MANIFEST)" \
@@ -45,13 +51,13 @@ $(BUILD)/kernel.all: $(LD_SCRIPT) $(LOCKFILE) $(MANIFEST) $(TARGET_SPEC) $(shell
 		--emit link="$(BUILD)/kernel.all"
 
 $(BUILD)/kernel.sym: $(BUILD)/kernel.all
-	$(GNU_TARGET)-objcopy \
+	$(OBJCOPY) \
 		--only-keep-debug \
 		"$(BUILD)/kernel.all" \
 		"$(BUILD)/kernel.sym"
 
 $(BUILD)/kernel: $(BUILD)/kernel.all
-	$(GNU_TARGET)-objcopy \
+	$(OBJCOPY) \
 		--strip-debug \
 		"$(BUILD)/kernel.all" \
 		"$(BUILD)/kernel"
@@ -65,3 +71,29 @@ check:
 		--target "$(TARGET_SPEC)" \
 		-Z build-std=core,alloc -Zbuild-std-features=compiler-builtins-mem -Z json-target-spec \
 		--features=$(KERNEL_CHECK_FEATURES)
+
+clean:
+	rm -rf build sysroot target config.toml
+
+install: all
+	@mkdir -pv "$(DESTDIR)/usr/lib/boot/"
+	cp -v $(BUILD)/kernel.all "$(DESTDIR)/usr/lib/boot/"
+	cp -v $(BUILD)/kernel.sym "$(DESTDIR)/usr/lib/boot/"
+	cp -v $(BUILD)/kernel "$(DESTDIR)/usr/lib/boot/"
+
+# test if booting
+# to ensure it's using this kernel, set COOKBOOK_SOURCE_IDENT env before build
+test: all
+	$(MAKE) install
+	REDOXER_SYSROOT=$(DESTDIR) redoxer exec uname -a
+
+# test with interactive gui
+test-gui: all
+	$(MAKE) install
+	REDOXER_SYSROOT=$(DESTDIR) redoxer exec --gui ion
+
+# test with relibc tests
+test-relibc: all
+	$(MAKE) install
+	REDOXER_SYSROOT=$(DESTDIR) redoxer pkg relibc-tests-bins
+	REDOXER_SYSROOT=$(DESTDIR) redoxer exec relibc-tests-runner

src/acpi/mod.rs

@@ -6,6 +6,7 @@ use core::ptr::NonNull;
 use alloc::{boxed::Box, string::String, vec::Vec};
 
 use hashbrown::HashMap;
+use rmm::{BumpAllocator, FrameAllocator, PageMapper};
 use spin::{Once, RwLock};
 
 use crate::{
@@ -33,7 +34,11 @@ mod spcr;
 pub mod srat;
 mod xsdt;
 
-unsafe fn map_linearly(addr: PhysicalAddress, len: usize, mapper: &mut crate::memory::PageMapper) {
+unsafe fn map_linearly(
+    addr: PhysicalAddress,
+    len: usize,
+    mapper: &mut PageMapper<RmmA, impl FrameAllocator>,
+) {
     unsafe {
         let base = PhysicalAddress::new(crate::memory::round_down_pages(addr.data()));
         let aligned_len = crate::memory::round_up_pages(len + (addr.data() - base.data()));
@@ -50,7 +55,10 @@ unsafe fn map_linearly(addr: PhysicalAddress, len: usize, mapper: &mut crate::me
     }
 }
 
-pub fn get_sdt(sdt_address: PhysicalAddress, mapper: &mut KernelMapper<true>) -> &'static Sdt {
+pub fn get_sdt(
+    sdt_address: PhysicalAddress,
+    mapper: &mut PageMapper<RmmA, impl FrameAllocator>,
+) -> &'static Sdt {
     let sdt;
 
     unsafe {
@@ -93,16 +101,20 @@ impl Rxsdt for RxsdtEnum {
 
 pub static RXSDT_ENUM: Once<RxsdtEnum> = Once::new();
 
-/// Initialses the global `RXSDT_ENUM` if RSDT or XSDT was found and maps the SDT pages.
+/// Initialises the global `RXSDT_ENUM` if RSDT or XSDT was found and maps the SDT pages.
-/// It does not perform any allocations
+///
-pub unsafe fn init_before_mem(already_supplied_rsdp: Option<NonNull<u8>>) {
+/// It does not use `TheFrameAllocator` nor does it heap-allocate.
+pub unsafe fn init_before_mem(
+    already_supplied_rsdp: Option<NonNull<u8>>,
+    mapper: &mut PageMapper<RmmA, BumpAllocator<RmmA>>,
+) {
     unsafe {
         // Search for RSDP
         let rsdp_opt = Rsdp::get_rsdp(already_supplied_rsdp);
 
         if let Some(rsdp) = rsdp_opt {
             debug!("SDT address: {:#x}", rsdp.sdt_address().data());
-            let rxsdt = get_sdt(rsdp.sdt_address(), &mut KernelMapper::lock_rw());
+            let rxsdt = get_sdt(rsdp.sdt_address(), mapper);
 
             let rxsdt = if let Some(rsdt) = Rsdt::new(rxsdt) {
                 let mut initialized = false;
@@ -139,7 +151,7 @@ pub unsafe fn init_before_mem(already_supplied_rsdp: Option<NonNull<u8>>) {
             // TODO: Don't touch ACPI tables in kernel?
 
             for sdt in rxsdt.iter() {
-                get_sdt(sdt, &mut KernelMapper::lock_rw());
+                get_sdt(sdt, mapper);
             }
         } else {
             error!("NO RSDP FOUND");

src/arch/aarch64/device/irqchip/gic.rs

@@ -1,8 +1,8 @@
 use super::InterruptController;
 use crate::{
     dtb::{
-        get_mmio_address,
         irqchip::{InterruptHandler, IrqCell, IrqDesc},
+        translate_mmio_address,
     },
     sync::CleanLockToken,
 };
@@ -60,7 +60,7 @@ impl GenericInterruptController {
             if chunk.size.is_none() {
                 break;
             }
-            let addr = get_mmio_address(fdt, node, &chunk).unwrap();
+            let addr = translate_mmio_address(fdt, node, &chunk).unwrap();
             match idx {
                 0 => (regs.0, regs.1) = (addr, chunk.size.unwrap()),
                 2 => (regs.2, regs.3) = (addr, chunk.size.unwrap()),

src/arch/aarch64/device/irqchip/gicv3.rs

@@ -5,8 +5,8 @@ use fdt::{node::NodeProperty, Fdt};
 use super::{gic::GicDistIf, InterruptController};
 use crate::{
     dtb::{
-        get_mmio_address,
         irqchip::{InterruptHandler, IrqCell, IrqDesc},
+        translate_mmio_address,
     },
     sync::CleanLockToken,
 };
@@ -53,7 +53,7 @@ impl GicV3 {
         // Read registers
         let mut chunks = node.reg().unwrap();
         if let Some(gicd) = chunks.next()
-            && let Some(addr) = get_mmio_address(fdt, &node, &gicd)
+            && let Some(addr) = translate_mmio_address(fdt, &node, &gicd)
         {
             unsafe {
                 self.gic_dist_if.init(crate::PHYS_OFFSET + addr);
@@ -62,7 +62,7 @@ impl GicV3 {
         for _ in 0..gicrs {
             if let Some(gicr) = chunks.next() {
                 self.gicrs.push((
-                    get_mmio_address(fdt, &node, &gicr).unwrap(),
+                    translate_mmio_address(fdt, &node, &gicr).unwrap(),
                     gicr.size.unwrap(),
                 ));
             }

src/arch/aarch64/start.rs

@@ -100,6 +100,15 @@ unsafe extern "C" fn start(args_ptr: *const KernelArgs) -> ! {
             // Initialize paging
             paging::init();
 
+            let mut mapper = rmm::PageMapper::current(rmm::TableKind::Kernel, bump_allocator);
+            #[cfg(feature = "acpi")]
+            {
+                use crate::acpi;
+                acpi::init_before_mem(args.acpi_rsdp(), &mut mapper);
+            }
+
+            crate::memory::init_mm(mapper.allocator_mut());
+
             crate::arch::misc::init(crate::cpu_set::LogicalCpuId::new(0));
 
             // Setup kernel heap

src/arch/riscv64/start.rs

@@ -105,7 +105,7 @@ unsafe extern "C" fn start(args_ptr: *const KernelArgs) -> ! {
             }
 
             // Initialize RMM
-            crate::startup::memory::init(&args, None, None);
+            let mut bump_allocator = crate::startup::memory::init(&args, None, None);
 
             let boot_hart_id =
                 get_boot_hart_id(args.env()).expect("Didn't get boot HART id from bootloader");
@@ -114,6 +114,8 @@ unsafe extern "C" fn start(args_ptr: *const KernelArgs) -> ! {
 
             paging::init();
 
+            crate::memory::init_mm(&mut bump_allocator);
+
             crate::arch::misc::init(crate::cpu_set::LogicalCpuId::new(0));
 
             // Setup kernel heap

src/arch/x86_shared/start.rs

@@ -4,6 +4,8 @@
 //! defined in other files inside of the `arch` module
 use core::{arch::naked_asm, cell::SyncUnsafeCell, mem::offset_of};
 
+use rmm::PageMapper;
+
 use crate::{
     allocator,
     arch::{device, gdt, idt, interrupt, paging},
@@ -112,13 +114,14 @@ unsafe extern "C" fn start(args_ptr: *const KernelArgs, stack_end: usize) -> ! {
             // Initialize paging
             paging::init();
 
+            let mut mapper = PageMapper::current(rmm::TableKind::Kernel, bump_allocator);
             if cfg!(feature = "acpi") {
-                crate::acpi::init_before_mem(args.acpi_rsdp());
+                crate::acpi::init_before_mem(args.acpi_rsdp(), &mut mapper);
             }
 
-            numa::init(&mut bump_allocator);
+            numa::init(mapper.allocator_mut());
 
-            crate::memory::init_mm(bump_allocator);
+            crate::memory::init_mm(mapper.allocator_mut());
 
             #[cfg(target_arch = "x86_64")]
             crate::arch::alternative::early_init(true);

src/context/context.rs

@@ -333,7 +333,6 @@ impl Context {
     pub fn unblock_no_ipi(&mut self) -> bool {
         if self.status.is_soft_blocked() {
             self.status = Status::Runnable;
-            self.wake = None;
             self.status_reason = "";
 
             true

src/context/mod.rs

@@ -9,13 +9,17 @@ use alloc::{
 use core::{cmp::Reverse, num::NonZeroUsize, ops::Deref};
 
 use crate::{
-    context::memory::AddrSpaceWrapper,
+    context::{
+        memory::AddrSpaceWrapper,
+        switch::{BASE_SLICE_TICKS, NANOS_PER_TICK, SCALE, SCHED_PRIO_TO_WEIGHT, TICK_INTERVAL},
+    },
     cpu_set::LogicalCpuSet,
+    ipi::{ipi, IpiKind, IpiTarget},
     memory::{RmmA, RmmArch, TableKind},
     percpu::PercpuBlock,
     sync::{
         ArcRwLockWriteGuard, CleanLockToken, LockToken, Mutex, MutexGuard, RwLock, RwLockReadGuard,
-        RwLockWriteGuard, L0, L1, L2, L4,
+        RwLockWriteGuard, L0, L1, L2, L3, L4,
     },
     syscall::error::Result,
 };
@@ -83,7 +87,7 @@ static IDLE_CONTEXTS: Mutex<L2, VecDeque<WeakContextRef>> = Mutex::new(VecDeque:
 pub struct RunContextData {
     // queue: VecDeque<WeakContextRef>,
     queue: BTreeMap<(u64, Reverse<u64>, u32), (u64, u64, WeakContextRef)>, // ((vd, rem_slice, ctxt_id), (vtime, weight, context))
-    timers: BTreeSet<(u128, WeakContextRef)>, // (wake, context)
+    timers: BTreeSet<(u128, WeakContextRef)>,                              // (wake, context)
     count: usize,
     v: u64,
     total_weight: u64,
@@ -135,6 +139,36 @@ pub fn run_contexts_try(token: LockToken<'_, L0>) -> Option<MutexGuard<'_, L1, R
     RUN_CONTEXTS.try_lock(token)
 }
 
+pub fn unblock_context(context_lock: &Arc<ContextLock>, token: &mut LockToken<'_, L3>) -> bool {
+    let cpu_id = {
+        let mut guard = context_lock.write(token.token());
+        if !guard.unblock_no_ipi() {
+            if guard.status.is_runnable() {
+                // already set to runnable externally
+                wakeup_context(context_lock);
+            }
+            return false;
+        }
+        guard.cpu_id
+    };
+
+    wakeup_context(context_lock);
+
+    if let Some(cpu_id) = cpu_id
+        && cpu_id != crate::cpu_id()
+    {
+        ipi(IpiKind::Wakeup, IpiTarget::Other);
+    }
+
+    true
+}
+
+pub fn wakeup_context(context_lock: &Arc<ContextLock>) {
+    let percpu: &PercpuBlock = PercpuBlock::current();
+    let weak = WeakContextRef(Arc::downgrade(context_lock));
+    percpu.switch_internals.wakeup_list.borrow_mut().push(weak);
+}
+
 pub fn init(token: &mut CleanLockToken) {
     let owner = None; // kmain not owned by any fd
     let mut context = Context::new(owner).expect("failed to create kmain context");
@@ -261,7 +295,6 @@ pub fn spawn(
     let context_lock = Arc::new(ContextLock::new(context));
     let context_ref = ContextRef(Arc::clone(&context_lock));
     let run_ref = WeakContextRef(Arc::downgrade(&context_ref.0));
-    idle_contexts(token.downgrade()).push_back(run_ref);
     contexts_mut(token.downgrade()).insert(context_ref);
 
     Ok(context_lock)

src/context/switch.rs

@@ -13,7 +13,7 @@ use crate::{
     percpu::PercpuBlock,
     sync::{ArcRwLockWriteGuard, CleanLockToken, L4},
 };
-use alloc::sync::Arc;
+use alloc::{sync::Arc, vec::Vec};
 use core::{
     cell::{Cell, RefCell},
     cmp::Reverse,
@@ -32,16 +32,16 @@ enum UpdateResult {
 }
 
 // A simple geometric series where value[i] ~= value[i + 1] * 1.25
-const SCHED_PRIO_TO_WEIGHT: [usize; 40] = [
+pub const SCHED_PRIO_TO_WEIGHT: [usize; 40] = [
     88761, 71755, 56483, 46273, 36291, 29154, 23254, 18705, 14949, 11916, 9548, 7620, 6100, 4904,
     3906, 3121, 2501, 1991, 1586, 1277, 1024, 820, 655, 526, 423, 335, 272, 215, 172, 137, 110, 87,
     70, 56, 45, 36, 29, 23, 18, 15,
 ];
 
-const SCALE: u128 = 1 << 40;
+pub const SCALE: u128 = 1 << 40;
-const TICK_INTERVAL: u64 = 3; // Approx 6.75 ms
+pub const TICK_INTERVAL: u64 = 3; // Approx 6.75 ms
-const BASE_SLICE_TICKS: u64 = TICK_INTERVAL * 3; // Approx 20.25 ms
+pub const BASE_SLICE_TICKS: u64 = TICK_INTERVAL * 3; // Approx 20.25 ms
-const NANOS_PER_TICK: u128 = 2_250_000; // 2.25 ms
+pub const NANOS_PER_TICK: u128 = 2_250_000; // 2.25 ms
 
 /// Determines if a given context is eligible to be scheduled on a given CPU (in
 /// principle, the current CPU).
@@ -190,6 +190,8 @@ pub fn switch(token: &mut CleanLockToken) -> SwitchResult {
     let mut wakeups = wakeup_contexts(token);
     let mut push_idle: SmallVec<[WeakContextRef; 16]> = SmallVec::new();
 
+    // These timers coukd have expired
+    let mut timers: SmallVec<[(u128, WeakContextRef); 16]> = SmallVec::new();
     if let Some(mut run_contexts) = run_contexts_try(token.token()) {
         // Pop Timers
         while let Some((wake, _)) = run_contexts.timers.first() {
@@ -197,12 +199,31 @@ pub fn switch(token: &mut CleanLockToken) -> SwitchResult {
                 break;
             }
 
-            if let Some((_, context_ref)) = run_contexts.timers.pop_first() {
+            if let Some(entry) = run_contexts.timers.pop_first() {
-                wakeups.push(context_ref);
+                timers.push(entry);
             }
         }
     }
 
+    for (wake, context_ref) in timers {
+        let Some(context_lock) = context_ref.upgrade() else {
+            continue;
+        };
+
+        let guard = context_lock.read(token.token());
+        if guard.status.is_soft_blocked() && guard.wake == Some(wake) {
+            wakeups.push(context_ref);
+        }
+    }
+
+    // Drain from percpu
+    {
+        let mut percpu_wake = percpu.switch_internals.wakeup_list.borrow_mut();
+        for context_ref in percpu_wake.drain(..) {
+            wakeups.push(context_ref.clone());
+        }
+    }
+
     if wakeups.len() > 0 {
         let mut run_contexts = run_contexts(token.token());
         for context_ref in wakeups {
@@ -388,9 +409,7 @@ pub fn switch(token: &mut CleanLockToken) -> SwitchResult {
     }
 }
 
-fn wakeup_contexts(
+fn wakeup_contexts(token: &mut CleanLockToken) -> SmallVec<[WeakContextRef; 16]> {
-    token: &mut CleanLockToken,
-) -> SmallVec<[WeakContextRef; 16]> {
     // TODO: Optimise this somehow
     let mut wakeups = SmallVec::new();
     let current_context = context::current();
@@ -687,6 +706,9 @@ pub struct ContextSwitchPercpu {
     /// The idle process.
     idle_ctxt: RefCell<Option<Arc<ContextLock>>>,
     pub(crate) being_sigkilled: Cell<bool>,
+
+    // wakeups
+    pub(crate) wakeup_list: RefCell<Vec<WeakContextRef>>,
 }
 
 impl ContextSwitchPercpu {
@@ -698,6 +720,7 @@ impl ContextSwitchPercpu {
             current_ctxt: RefCell::new(None),
             idle_ctxt: RefCell::new(None),
             being_sigkilled: Cell::new(false),
+            wakeup_list: RefCell::new(Vec::new()),
 
             #[cfg(feature = "profiling")]
             current_dbg_id: core::sync::atomic::AtomicU32::new(!0),

src/dtb/mod.rs

@@ -102,53 +102,145 @@ pub fn register_dev_memory_ranges(dt: &Fdt) {
         }
     }
 
-    let Some(soc_node) = dt.find_node("/soc") else {
+    if let Some(soc_node) = dt.find_node("/soc") {
-        warn!("failed to find /soc in devicetree");
+        if let Some(reg) = soc_node.ranges() {
-        return;
+            for chunk in reg {
-    };
+                debug!(
-    let Some(reg) = soc_node.ranges() else {
+                    "dev mem 0x{:08x} 0x{:08x} 0x{:08x} 0x{:08x}",
-        warn!("devicetree /soc has no ranges");
+                    chunk.child_bus_address_hi,
-        return;
+                    chunk.child_bus_address,
-    };
+                    chunk.parent_bus_address,
-    for chunk in reg {
+                    chunk.size
-        debug!(
+                );
-            "dev mem 0x{:08x} 0x{:08x} 0x{:08x} 0x{:08x}",
-            chunk.child_bus_address_hi,
-            chunk.child_bus_address,
-            chunk.parent_bus_address,
-            chunk.size
-        );
 
-        /*TODO: soc memory may contain all free memory!
+                /*TODO: soc memory may contain all free memory!
-        register_memory_region(
+                register_memory_region(
-            chunk.parent_bus_address,
+                    chunk.parent_bus_address,
-            chunk.size,
+                    chunk.size,
-            BootloaderMemoryKind::Device,
+                    BootloaderMemoryKind::Device,
-        );*/
+                );*/
-    }
+            }
+        } else {
+            warn!("devicetree /soc has no ranges");
+        }
 
-    // also add all soc-internal devices because they might not be shown in ranges
+        // also add direct /soc children because they might not be shown in
-    // (identity-mapped soc bus may have empty ranges)
+        // ranges (an identity-mapped bus may have empty ranges)
-    for device in soc_node.children() {
+        for device in soc_node.children() {
-        if let Some(reg) = device.reg() {
+            if let Some(reg) = device.reg() {
-            for entry in reg {
+                for entry in reg {
-                if let Some(size) = entry.size {
+                    if let Some(size) = entry.size {
-                    let addr = entry.starting_address as usize;
+                        let addr = entry.starting_address as usize;
-                    if let Some(mapped_addr) = get_mmio_address(dt, &device, &entry) {
+                        if let Some(mapped_addr) = get_mmio_address(dt, &device, &entry) {
-                        debug!(
+                            debug!(
-                            "soc device {} 0x{:08x} -> 0x{:08x} size 0x{:08x}",
+                                "soc device {} 0x{:08x} -> 0x{:08x} size 0x{:08x}",
-                            device.name, addr, mapped_addr, size
+                                device.name, addr, mapped_addr, size
-                        );
+                            );
-                        register_memory_region(mapped_addr, size, BootloaderMemoryKind::Device);
+                            register_memory_region(mapped_addr, size, BootloaderMemoryKind::Device);
+                        }
                     }
                 }
             }
         }
+    } else {
+        warn!("failed to find /soc in devicetree");
+    }
+
+    // The selected console may be below a nested bus whose own `reg` range
+    // does not cover all children. Register the exact translated range so it
+    // remains mapped after the boot-time identity map is replaced.
+    if let Some((address, size, _, _, _)) = diag_uart_range(dt) {
+        debug!(
+            "diagnostic UART 0x{:08x} size 0x{:08x}",
+            address.data(),
+            size
+        );
+        register_memory_region(address.data(), size, BootloaderMemoryKind::Device);
+    }
+
+    // Interrupt controllers are not required to live below /soc. Some
+    // devicetrees place the primary GIC directly below the root node, so its
+    // register ranges would otherwise be absent from the kernel physmap.
+    if let Some(root) = dt.find_node("/") {
+        for controller in root
+            .children()
+            .filter(|node| node.property("interrupt-controller").is_some())
+        {
+            let Some(regions) = controller.reg() else {
+                continue;
+            };
+            for region in regions {
+                let Some(size) = region.size else {
+                    continue;
+                };
+                let Some(address) = translate_mmio_address(dt, &controller, &region) else {
+                    continue;
+                };
+                debug!(
+                    "root interrupt controller {} 0x{:08x} size 0x{:08x}",
+                    controller.name, address, size
+                );
+                register_memory_region(address, size, BootloaderMemoryKind::Device);
+            }
+        }
     }
 }
 
-// FIXME return PhysicalAddress
+fn same_node(left: FdtNode<'_, '_>, right: FdtNode<'_, '_>) -> bool {
-pub fn get_mmio_address(fdt: &Fdt, _device: &FdtNode, region: &MemoryRegion) -> Option<usize> {
+    if left.name != right.name {
+        return false;
+    }
+    // FdtNode is reconstructed while walking the tree and has no identity
+    // operation. A property's value is a slice into the original DTB, so equal
+    // `reg` slice pointers identify the same node occurrence without relying
+    // on names that may repeat below different buses.
+    match (left.property("reg"), right.property("reg")) {
+        (Some(left_reg), Some(right_reg)) => core::ptr::eq(left_reg.value, right_reg.value),
+        _ => false,
+    }
+}
+
+fn translate_bus_address(bus: FdtNode<'_, '_>, address: usize, size: usize) -> Option<usize> {
+    let ranges_property = bus.property("ranges")?;
+    if ranges_property.value.is_empty() {
+        return Some(address);
+    }
+
+    let last_offset = size.saturating_sub(1);
+    let ranges = bus.ranges()?;
+    for range in ranges {
+        let Some(offset) = address.checked_sub(range.child_bus_address) else {
+            continue;
+        };
+        if offset < range.size && last_offset < range.size - offset {
+            return range.parent_bus_address.checked_add(offset);
+        }
+    }
+    None
+}
+
+fn translate_from_subtree(
+    bus_or_device: FdtNode<'_, '_>,
+    target: FdtNode<'_, '_>,
+    address: usize,
+    size: usize,
+) -> Option<usize> {
+    if same_node(bus_or_device, target) {
+        return Some(address);
+    }
+
+    for child in bus_or_device.children() {
+        if let Some(child_address) = translate_from_subtree(child, target, address, size) {
+            // `bus_or_device` is the bus parent of the subtree that matched.
+            return translate_bus_address(bus_or_device, child_address, size);
+        }
+    }
+    None
+}
+
+/// Translate a device's bus-relative `reg` address through every ancestor's
+/// `ranges` property until it reaches the CPU physical address space.
+pub fn translate_mmio_address(fdt: &Fdt, device: &FdtNode, region: &MemoryRegion) -> Option<usize> {
     /* DT spec 2.3.8 "ranges":
      * The ranges property provides a means of defining a mapping or translation between
      * the address space of the bus (the child address space) and the address space of the bus
@@ -159,15 +251,32 @@ pub fn get_mmio_address(fdt: &Fdt, _device: &FdtNode, region: &MemoryRegion) ->
      * children of the node and the parent address space.
      */
 
-    // FIXME assumes all the devices are connected to CPUs via the /soc bus
+    let address = region.starting_address as usize;
+    let size = region.size.unwrap_or(1);
+    let root = fdt.find_node("/")?;
+
+    // The root is already the CPU address space, so only its children perform
+    // translations. This also supports devices that are not under `/soc`.
+    for child in root.children() {
+        if let Some(translated) = translate_from_subtree(child, *device, address, size) {
+            translated.checked_add(size.saturating_sub(1))?;
+            return Some(translated);
+        }
+    }
+    None
+}
+
+// FIXME return PhysicalAddress
+pub fn get_mmio_address(fdt: &Fdt, _device: &FdtNode, region: &MemoryRegion) -> Option<usize> {
     let mut mapped_addr = region.starting_address as usize;
     let size = region.size.unwrap_or(0).saturating_sub(1);
     let last_address = mapped_addr.saturating_add(size);
     if let Some(parent) = fdt.find_node("/soc") {
-        let mut ranges = parent.ranges().map(|f| f.peekable())?;
+        let mut ranges = parent.ranges().map(|ranges| ranges.peekable())?;
         if ranges.peek().is_some() {
-            let parent_range = ranges.find(|x| {
+            let parent_range = ranges.find(|range| {
-                x.child_bus_address <= mapped_addr && last_address - x.child_bus_address <= x.size
+                range.child_bus_address <= mapped_addr
+                    && last_address - range.child_bus_address <= range.size
             })?;
             mapped_addr = parent_range
                 .parent_bus_address
@@ -219,7 +328,7 @@ pub fn diag_uart_range<'a>(dtb: &'a Fdt) -> Option<(PhysicalAddress, usize, bool
 
     let mut reg = uart_node.reg()?;
     let memory = reg.next()?;
-    let address = get_mmio_address(dtb, &uart_node, &memory)?;
+    let address = translate_mmio_address(dtb, &uart_node, &memory)?;
 
     Some((
         PhysicalAddress::new(address),
@@ -244,3 +353,38 @@ pub fn fill_env_data(dt: &Fdt, env_base: usize) -> usize {
         0
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::translate_mmio_address;
+    use fdt::Fdt;
+
+    static MMIO_DTB: &[u8] = include_bytes!("testdata/mmio.dtb");
+
+    fn translated(path: &str) -> Option<usize> {
+        let fdt = Fdt::new(MMIO_DTB).unwrap();
+        let node = fdt.find_node(path).unwrap();
+        let region = node.reg().unwrap().next().unwrap();
+        translate_mmio_address(&fdt, &node, &region)
+    }
+
+    #[test]
+    fn translates_uart_through_nested_and_empty_ranges() {
+        assert_eq!(translated("/soc/bus@1000/serial@200"), Some(0x1200));
+    }
+
+    #[test]
+    fn accepts_region_ending_exactly_at_range_boundary() {
+        assert_eq!(translated("/soc/bus@1000/device@ff0"), Some(0x1ff0));
+    }
+
+    #[test]
+    fn rejects_region_crossing_range_boundary() {
+        assert_eq!(translated("/soc/bus@1000/device@ff1"), None);
+    }
+
+    #[test]
+    fn empty_ranges_is_identity_mapping() {
+        assert_eq!(translated("/identity-bus/device@3000"), Some(0x3000));
+    }
+}

src/dtb/testdata/mmio.dts

@@ -0,0 +1,48 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	chosen {
+		stdout-path = "/soc/bus@1000/serial@200:115200n8";
+	};
+
+	soc {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		bus@1000 {
+			compatible = "simple-bus";
+			#address-cells = <1>;
+			#size-cells = <1>;
+			reg = <0x0 0x1000 0x0 0x1000>;
+			ranges = <0x0 0x0 0x1000 0x1000>;
+
+			serial@200 {
+				reg = <0x200 0x18>;
+			};
+
+			device@ff0 {
+				reg = <0xff0 0x10>;
+			};
+
+			device@ff1 {
+				reg = <0xff1 0x10>;
+			};
+		};
+	};
+
+	identity-bus {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		device@3000 {
+			reg = <0x0 0x3000 0x0 0x20>;
+		};
+	};
+};

src/event.rs

@@ -2,7 +2,7 @@ use alloc::sync::Arc;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use hashbrown::{hash_map::DefaultHashBuilder, HashMap};
 use smallvec::SmallVec;
-use syscall::data::GlobalSchemes;
+use syscall::{data::GlobalSchemes, EAGAIN, EINTR};
 
 use crate::{
     context,
@@ -29,6 +29,9 @@ pub struct EventQueue {
     /// handle to the SAME queue; the queue must survive until the last fd
     /// closes. Starts at 1 for the fd created by `open`.
     refs: AtomicUsize,
+    /// Pending EVENT_TIMEOUT_ID timeout recorded by `write()` and consumed
+    /// by `read_with_timeout()` (upstream event-timeout support).
+    timeout_opt: Mutex<L1, Option<usize>>,
 }
 
 const EVENTFD_COUNTER_MAX: u64 = u64::MAX - 1;
@@ -48,6 +51,7 @@ impl EventQueue {
             id,
             queue: WaitQueue::new(),
             refs: AtomicUsize::new(1),
+            timeout_opt: Mutex::new(None),
         }
     }
 
@@ -71,8 +75,61 @@ impl EventQueue {
             .receive_into_user(buf, block, "EventQueue::read", token)
     }
 
+    pub fn read_with_timeout(
+        &self,
+        buf: UserSliceWo,
+        timeout: usize,
+        token: &mut CleanLockToken,
+    ) -> Result<usize> {
+        // if zero, instant timeout
+        let block = timeout > 0;
+        if block {
+            let mut time = crate::time::monotonic(token);
+            time += timeout as u128 * 1_000_000;
+            context::current().write(token.token()).wake = Some(time);
+        }
+        let r = self
+            .queue
+            .receive_into_user(buf, block, "EventQueue::read_with_timeout", token);
+        match (r, block) {
+            (Ok(r), _) => return Ok(r),
+            (err @ Err(Error { errno: EINTR }), true) => {
+                let old_wake = context::current().write(token.token()).wake.take();
+                // The scheduler clears `wake` on timeout
+                if !old_wake.is_none() {
+                    return err;
+                }
+                // proceed writing timeout
+            }
+            (Err(Error { errno: EAGAIN }), false) => {
+                // proceed writing timeout
+            }
+            (err, _) => return err,
+        };
+
+        // TODO: let the scheduler write this for us?
+        let event = Event {
+            id: syscall::EVENT_TIMEOUT_ID,
+            // TODO: it's undefined when flags is written to EVENT_TIMEOUT_ID
+            flags: EventFlags::EVENT_READ,
+            data: timeout,
+        };
+
+        let bytes_copied = buf.copy_common_bytes_from_slice(&event)?;
+        return Ok(bytes_copied);
+    }
+
     pub fn write(&self, events: &[Event], token: &mut CleanLockToken) -> Result<usize> {
         for event in events {
+            if event.id == syscall::EVENT_TIMEOUT_ID {
+                if event.flags.is_empty() {
+                    self.timeout_opt.lock(token.token()).take();
+                } else {
+                    *self.timeout_opt.lock(token.token()) = Some(event.data);
+                }
+
+                continue;
+            }
             let file = {
                 let context_ref = context::current();
                 let mut context = context_ref.read(token.token());

src/memory/mod.rs

@@ -74,30 +74,36 @@ pub fn total_frames() -> usize {
 
 /// Allocate a range of frames
 pub fn allocate_p2frame(order: u32) -> Option<Frame> {
-    let initial_index = get_round_robin_index();
+    static RR_INDEX: Mutex<u8> = Mutex::new(0);
-    let mut index = initial_index;
+    let len = FREE_LISTS.get().unwrap().len();
 
-    loop {
+    if len == 1 {
-        if let Some(frame) = allocate_p2frame_complex(order, (), None, order, index).map(|(f, _)| f)
+        return allocate_p2frame_complex(order, (), None, order, 0).map(|e| e.0);
-        {
+    }
-            return Some(frame);
+
-        }
+    let index = {
-        index = get_round_robin_index();
+        let mut lock = RR_INDEX.lock();
-        if index == initial_index {
+        let index =
-            return None;
+            usize::try_from(*lock).expect("Maximum number of memory regions supported is 128");
+        *lock = u8::try_from((index + 1) % len).expect("Maximum number of memory regions is 128");
+        index
+    };
+    for i in index..len {
+        if let Some(frame) = allocate_p2frame_complex(order, (), None, order, i) {
+            return Some(frame.0);
         }
     }
+    for i in 0..index {
+        if let Some(frame) = allocate_p2frame_complex(order, (), None, order, i) {
+            return Some(frame.0);
+        }
+    }
+    None
 }
 pub fn allocate_frame() -> Option<Frame> {
     allocate_p2frame(0)
 }
 
-fn get_round_robin_index() -> usize {
-    static CURRENT_INDEX: AtomicUsize = AtomicUsize::new(0);
-    let len = FREE_LISTS.get().unwrap().len();
-    CURRENT_INDEX.fetch_add(1, Ordering::Relaxed) % len
-}
-
 // TODO: Flags, strategy
 pub fn allocate_p2frame_complex(
     _req_order: u32,
@@ -543,7 +549,7 @@ const _: () = {
 };
 
 #[cold]
-fn init_sections(mut allocator: BumpAllocator<RmmA>) {
+fn init_sections(mut allocator: &mut BumpAllocator<RmmA>) {
     let number_of_memory_regions = numa::number_of_memory_regions();
 
     let (free_areas, offset_into_first_free_area) = allocator.free_areas();
@@ -952,7 +958,7 @@ fn init_sections(mut allocator: BumpAllocator<RmmA>) {
 }
 
 #[cold]
-pub fn init_mm(allocator: BumpAllocator<RmmA>) {
+pub fn init_mm(allocator: &mut BumpAllocator<RmmA>) {
     init_sections(allocator);
 
     unsafe {

src/scheme/proc.rs

@@ -3,8 +3,8 @@ use crate::{
         self,
         context::{HardBlockedReason, LockedFdTbl, SignalState},
         file::InternalFlags,
-        memory::{handle_notify_files, AddrSpace, AddrSpaceWrapper, Grant, PageSpan},
+        memory::{handle_notify_files, AddrSpace, AddrSpaceWrapper, Grant, PageSpan, UnmapVec},
-        Context, ContextLock, Status,
+        unblock_context, wakeup_context, Context, ContextLock, Status,
     },
     memory::{Page, VirtualAddress, PAGE_SIZE},
     ptrace,
@@ -1580,6 +1580,7 @@ impl ContextHandle {
                         reason: HardBlockedReason::NotYetStarted,
                     } => {
                         *status = Status::Runnable;
+                        wakeup_context(&context);
                         Ok(buf.len())
                     }
                     _ => Err(Error::new(EINVAL)),
@@ -1747,12 +1748,12 @@ impl ContextHandle {
                         } = guard.status
                         {
                             guard.status = Status::Runnable;
+                            wakeup_context(&context);
                         }
                         Ok(size_of::<usize>())
                     }
                     ContextVerb::Interrupt => {
-                        let mut guard = context.write(token.token());
+                        unblock_context(&context, &mut token.token().downgrade());
-                        guard.unblock();
                         Ok(size_of::<usize>())
                     }
                     ContextVerb::ForceKill => {
@@ -1783,13 +1784,16 @@ impl ContextHandle {
                             }
                             crate::syscall::exit_this_context(None, token);
                         } else {
-                            let mut ctxt = context.write(token.token());
+                            {
-                            //trace!("FORCEKILL NONSELF={} {}, SELF={}", ctxt.debug_id, ctxt.pid, context::current().read().debug_id);
+                                let mut ctxt = context.write(token.token());
-                            if let context::Status::Dead { .. } = ctxt.status {
+                                //trace!("FORCEKILL NONSELF={} {}, SELF={}", ctxt.debug_id, ctxt.pid, context::current().read().debug_id);
-                                return Ok(size_of::<usize>());
+                                if ctxt.status.is_dead() {
+                                    return Ok(size_of::<usize>());
+                                }
+                                ctxt.status = context::Status::Runnable;
+                                ctxt.being_sigkilled = true;
                             }
-                            ctxt.status = context::Status::Runnable;
+                            wakeup_context(&context);
-                            ctxt.being_sigkilled = true;
                             Ok(size_of::<usize>())
                         }
                     }

src/scheme/user.rs

@@ -22,10 +22,12 @@ use crate::{
             AddrSpace, AddrSpaceWrapper, BorrowedFmapSource, Grant, GrantFileRef, MmapMode,
             PageSpan, DANGLING,
         },
-        BorrowedHtBuf, ContextLock, PreemptGuard, PreemptGuardL1, Status,
+        unblock_context, wakeup_context, BorrowedHtBuf, ContextLock, PreemptGuard, PreemptGuardL1,
+        Status, WeakContextRef,
     },
     event,
     memory::{Frame, Page, VirtualAddress, PAGE_SIZE},
+    percpu::PercpuBlock,
     scheme::SchemeId,
     sync::{CleanLockToken, LockToken, Mutex, RwLock, WaitQueue, L1},
     syscall::{
@@ -894,7 +896,7 @@ impl UserInner {
                     }
                 };
 
-                let context = context.upgrade().ok_or(Error::new(ESRCH))?;
+                let context_lock = context.upgrade().ok_or(Error::new(ESRCH))?;
 
                 let mut lock_token = token.token();
                 let (frame, _) = AddrSpace::current()?
@@ -905,12 +907,13 @@ impl UserInner {
                     .ok_or(Error::new(EFAULT))?;
 
                 {
-                    let mut context = context.write(token.token());
+                    let mut context = context_lock.write(token.token());
                     if let Status::HardBlocked {
                         reason: HardBlockedReason::AwaitingMmap { .. },
                     } = context.status
                     {
-                        context.status = Status::Runnable
+                        context.status = Status::Runnable;
+                        wakeup_context(&context_lock);
                     }
                     context.fmap_ret = Some(Frame::containing(frame));
                 }
@@ -982,7 +985,7 @@ impl UserInner {
                         match context.upgrade() {
                             Some(context) => {
                                 *o = State::Responded(response);
-                                context.write(lock_token.token()).unblock();
+                                unblock_context(&context, &mut lock_token.token().downgrade());
                             }
                             _ => {
                                 states.remove(tag as usize);

src/startup/mod.rs

@@ -7,7 +7,7 @@ use core::{
 
 use crate::{
     arch::interrupt,
-    context::{self, switch::SwitchResult},
+    context::{self, switch::SwitchResult, wakeup_context, Status},
     memory::{PhysicalAddress, RmmA, RmmArch},
     profiling, scheme,
     sync::CleanLockToken,
@@ -175,13 +175,15 @@ pub(crate) fn kmain(bootstrap: Bootstrap) -> ! {
     match context::spawn(true, owner, userspace_init, &mut token) {
         Ok(context_lock) => {
             let mut context = context_lock.write(token.token());
-            context.status = context::Status::Runnable;
+            context.status = Status::Runnable;
             context.name.clear();
             context.name.push_str("[bootstrap]");
 
             // TODO: Remove these from kernel
             context.euid = 0;
             context.egid = 0;
+
+            wakeup_context(&context_lock);
         }
         Err(err) => {
             panic!("failed to spawn userspace_init: {:?}", err);

src/sync/wait_condition.rs

@@ -6,7 +6,7 @@ use alloc::{
 };
 
 use crate::{
-    context::{self, ContextLock, PreemptGuardL2},
+    context::{self, unblock_context, ContextLock, PreemptGuardL2},
     sync::{CleanLockToken, LockToken, Mutex, L1, L2, L3},
 };
 
@@ -33,7 +33,7 @@ impl WaitCondition {
         let len = contexts.len();
         while let Some(context_weak) = contexts.pop() {
             if let Some(context_ref) = context_weak.upgrade() {
-                context_ref.write(token.token()).unblock();
+                unblock_context(&context_ref, &mut token.token());
             }
         }
         len
@@ -46,7 +46,7 @@ impl WaitCondition {
         let len = contexts.len();
         for context_weak in contexts.iter() {
             if let Some(context_ref) = context_weak.upgrade() {
-                context_ref.write(token.token()).unblock();
+                unblock_context(&context_ref, &mut token.token());
             }
         }
         len

src/syscall/fs.rs

@@ -311,43 +311,36 @@ pub fn dup2(
     buf: UserSliceRo,
     token: &mut CleanLockToken,
 ) -> Result<FileHandle> {
-    if fd == new_fd {
+    if fd == new_fd && buf.is_empty() {
-        // Self-dup: a no-op if no buffer is supplied. But a self-dup2 WITH a
+        return Ok(new_fd);
-        // buffer is a meaningful in-place operation — e.g. relibc issues
+    }
-        // dup2(ft, ft, "refresh") to re-materialize the inherited filetable, so
-        // it must NOT short-circuit. Duplicate first (fd is still valid), then
-        // replace the descriptor in place. Only this self-dup path is new; the
-        // normal path below is unchanged so ordinary dup2 (process-spawn stdio)
-        // keeps its exact original behavior.
-        if buf.is_empty() {
-            return Ok(new_fd);
-        }
-        let new_file = duplicate_file(fd, buf, false, token)?;
-        let old_file = {
-            let current_lock = context::current();
-            let mut current = current_lock.read(token.token());
-            let (context, mut token) = current.token_split();
-            let old_file = context.remove_file(new_fd, &mut token);
-            context
-                .insert_file(new_fd, new_file, &mut token)
-                .ok_or(Error::new(EMFILE))?;
-            old_file
-        };
-        if let Some(old) = old_file {
-            let _ = old.close(token);
-        }
-        Ok(new_fd)
-    } else {
-        let _ = close(new_fd, token);
-        let new_file = duplicate_file(fd, buf, false, token)?;
 
+    let new_file = duplicate_file(fd, buf, false, token)?;
+
+    let old_file = {
         let current_lock = context::current();
         let mut current = current_lock.read(token.token());
         let (context, mut token) = current.token_split();
-        context
+
+        let old_file = context.remove_file(new_fd, &mut token);
+
+        if context
             .insert_file(new_fd, new_file, &mut token)
-            .ok_or(Error::new(EMFILE))
+            .is_none()
+        {
+            if let Some(old) = old_file {
+                context.insert_file(new_fd, old, &mut token);
+            }
+            return Err(Error::new(EMFILE));
+        }
+        old_file
+    };
+
+    if let Some(old) = old_file {
+        let _ = old.close(token);
     }
+
+    Ok(new_fd)
 }
 pub fn call(
     fd: FileHandle,

src/syscall/futex.rs

@@ -15,11 +15,10 @@ use crate::{
     context::{
         self,
         memory::{AddrSpace, AddrSpaceWrapper},
-        ContextLock,
+        unblock_context, ContextLock,
     },
     memory::{Page, PhysicalAddress, VirtualAddress},
     sync::{CleanLockToken, Mutex, L1},
-    time,
 };
 
 use crate::syscall::{
@@ -39,9 +38,11 @@ pub struct FutexEntry {
     // CoW.
     target_virtaddr: VirtualAddress,
     // Context to wake up, and compare address spaces.
-    context_lock: Arc<ContextLock>,
+    context_lock: Weak<ContextLock>,
     // address space to check against if virt matches but not phys
     addr_space: Weak<AddrSpaceWrapper>,
+    // FUTEX_WAIT_MULTIPLE: which array index this waiter corresponds to,
+    // reported back through Context::futex_wake_index on wake.
     waitv_index: Option<usize>,
 }
 
@@ -52,6 +53,17 @@ pub struct FutexEntry {
 static FUTEXES: Mutex<L1, FutexList> =
     Mutex::new(FutexList::with_hasher(DefaultHashBuilder::new()));
 
+pub fn get_futex_stat(token: &mut CleanLockToken) -> (usize, usize) {
+    let mut regc = 0;
+    let mut regl = 0;
+    let registry = FUTEXES.lock(token.token());
+    for (_, v) in registry.iter() {
+        regl += v.len();
+        regc += 1;
+    }
+    (regc, regl)
+}
+
 fn validate_and_translate_virt(space: &AddrSpace, addr: VirtualAddress) -> Option<PhysicalAddress> {
     // TODO: Move this elsewhere!
     if addr.data().saturating_add(size_of::<usize>()) >= crate::USER_END_OFFSET {
@@ -142,9 +154,7 @@ pub fn futex(
                 {
                     let mut context = context_lock.write(token.token());
 
-                    context.wake = timeout_opt.map(|TimeSpec { tv_sec, tv_nsec }| {
+                    context.wake = timeout_opt.map(|time| time.to_nanos());
-                        tv_sec as u128 * time::NANOS_PER_SEC + tv_nsec as u128
-                    });
                     if let Some((tctl, pctl, _)) = context.sigcontrol()
                         && tctl.currently_pending_unblocked(pctl) != 0
                     {
@@ -159,7 +169,7 @@ pub fn futex(
                     .or_insert_with(Vec::new)
                     .push(FutexEntry {
                         target_virtaddr,
-                        context_lock: context_lock.clone(),
+                        context_lock: Arc::downgrade(&context_lock),
                         addr_space: Arc::downgrade(&current_addrsp),
                         waitv_index: None,
                     });
@@ -198,25 +208,28 @@ pub fn futex(
                         if futex.target_virtaddr != target_virtaddr
                             || !current_addrsp_weak.ptr_eq(&futex.addr_space)
                         {
-                            i += 1;
+                            if futex.addr_space.strong_count() == 0 {
+                                futexes.swap_remove(i);
+                            } else {
+                                i += 1;
+                            }
                             continue;
                         }
-                        let should_wake = {
+                        if let Some(ctx) = futex.context_lock.upgrade() {
-                            let mut context = futex.context_lock.write(token.token());
+                            // FUTEX_WAIT_MULTIPLE wake-index bookkeeping:
+                            // record which array index woke the waiter (the
+                            // first wake wins) before unblocking.
                             if let Some(index) = futex.waitv_index {
+                                let mut context = ctx.write(token.token());
                                 if context.futex_wake_index.is_none() {
                                     context.futex_wake_index = Some(index);
                                 }
+                                drop(context);
                             }
-                            context.unblock();
+                            unblock_context(&ctx, &mut token.token().downgrade());
-                            true
-                        };
-                        if should_wake {
-                            futexes.swap_remove(i);
-                            woken += 1;
-                        } else {
-                            i += 1;
                         }
+                        futexes.swap_remove(i);
+                        woken += 1;
                     }
 
                     futexes.is_empty()
@@ -260,7 +273,9 @@ pub fn futex(
                             continue;
                         }
                         if woken < val {
-                            futex.context_lock.write(token.token()).unblock();
+                            if let Some(ctx) = futex.context_lock.upgrade() {
+                                unblock_context(&ctx, &mut token.token().downgrade());
+                            }
                             futexes.remove(i);
                             woken += 1;
                         } else if requeued < val2 {
@@ -288,9 +303,10 @@ pub fn futex(
             Ok(woken + requeued)
         }
         FUTEX_WAIT_MULTIPLE => {
-            // Wait on multiple futexes atomically; return the index of the first
+            // Wait on multiple futexes atomically; return the index of the
-            // one that is woken. Semantics: val = number of FutexWaitv entries,
+            // first one that is woken. Semantics: val = number of FutexWaitv
-            // addr2 = pointer to the array, val2 = optional TimeSpec timeout.
+            // entries, addr2 = pointer to the array, val2 = optional TimeSpec
+            // timeout. Linux 7.1 kernel/futex/waitv.c futex_waitv().
             let count = val;
             if count == 0 || count > 128 {
                 return Err(Error::new(EINVAL));
@@ -344,9 +360,7 @@ pub fn futex(
 
                 {
                     let mut context = context_lock.write(token.token());
-                    context.wake = timeout_opt.map(|TimeSpec { tv_sec, tv_nsec }| {
+                    context.wake = timeout_opt.map(|ts| ts.to_nanos());
-                        tv_sec as u128 * time::NANOS_PER_SEC + tv_nsec as u128
-                    });
                     context.futex_wake_index = None;
                     if let Some((tctl, pctl, _)) = context.sigcontrol()
                         && tctl.currently_pending_unblocked(pctl) != 0
@@ -362,7 +376,7 @@ pub fn futex(
                         .or_insert_with(Vec::new)
                         .push(FutexEntry {
                             target_virtaddr: virt,
-                            context_lock: context_lock.clone(),
+                            context_lock: Arc::downgrade(&context_lock),
                             addr_space: Arc::downgrade(&current_addrsp),
                             waitv_index: Some(i),
                         });