feat(starry-kernel): support futex WAKE_OP

os/StarryOS/kernel/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- support `FUTEX_WAKE_OP` in Starry futex syscall handling.
 - *(prctl)* implement `PR_SET_CHILD_SUBREAPER` and `PR_GET_CHILD_SUBREAPER` with orphan reparenting tests.
 
 ## [0.5.12](https://github.com/rcore-os/tgoskits/compare/starry-kernel-v0.5.11...starry-kernel-v0.5.12) - 2026-05-22

os/StarryOS/kernel/src/syscall/fs/io.rs

@@ -672,12 +672,12 @@ fn do_send(mut src: SendFile, mut dst: SendFile, len: usize) -> AxResult<usize>
             *pos += bytes_written as u64;
             user.vm_write(*pos)?;
         }
+        total_written += bytes_written;
+        remaining -= bytes_written;
+
         if bytes_written < bytes_read {
             break;
         }
-
-        total_written += bytes_written;
-        remaining -= bytes_written;
     }
 
     Ok(total_written)

os/StarryOS/kernel/src/syscall/sync/futex.rs

@@ -4,8 +4,10 @@ use ax_errno::{AxError, AxResult};
 use ax_runtime::hal::time::{TimeValue, monotonic_time, wall_time};
 use ax_task::current;
 use linux_raw_sys::general::{
-    FUTEX_CLOCK_REALTIME, FUTEX_CMP_REQUEUE, FUTEX_REQUEUE, FUTEX_WAIT, FUTEX_WAIT_BITSET,
-    FUTEX_WAKE, FUTEX_WAKE_BITSET, robust_list_head, timespec,
+    FUTEX_CLOCK_REALTIME, FUTEX_CMP_REQUEUE, FUTEX_OP_ADD, FUTEX_OP_ANDN, FUTEX_OP_CMP_EQ,
+    FUTEX_OP_CMP_GE, FUTEX_OP_CMP_GT, FUTEX_OP_CMP_LE, FUTEX_OP_CMP_LT, FUTEX_OP_CMP_NE,
+    FUTEX_OP_OPARG_SHIFT, FUTEX_OP_OR, FUTEX_OP_SET, FUTEX_OP_XOR, FUTEX_REQUEUE, FUTEX_WAIT,
+    FUTEX_WAIT_BITSET, FUTEX_WAKE, FUTEX_WAKE_BITSET, FUTEX_WAKE_OP, robust_list_head, timespec,
 };
 use starry_vm::{VmMutPtr, VmPtr};
 
@@ -26,6 +28,7 @@ enum FutexCommand {
     WakeBitset,
     Requeue,
     CmpRequeue,
+    WakeOp,
 }
 
 struct ParsedFutexOp {
@@ -50,6 +53,61 @@ fn validate_futex_word(uaddr: *const u32) -> AxResult<()> {
     Ok(())
 }
 
+fn sign_extend_12(value: u32) -> i32 {
+    ((value << 20) as i32) >> 20
+}
+
+fn futex_wake_op_arg(raw_op: u32, encoded_op: u32) -> i32 {
+    let mut oparg = sign_extend_12((encoded_op >> 12) & 0xfff);
+    if raw_op & FUTEX_OP_OPARG_SHIFT != 0 {
+        oparg = (1u32 << ((oparg & 31) as u32)) as i32;
+    }
+    oparg
+}
+
+fn apply_futex_wake_op(old_value: u32, raw_op: u32, oparg: i32) -> AxResult<u32> {
+    let op = raw_op & !FUTEX_OP_OPARG_SHIFT;
+    let new_value = match op {
+        FUTEX_OP_SET => oparg as u32,
+        FUTEX_OP_ADD => (old_value as i32).wrapping_add(oparg) as u32,
+        FUTEX_OP_OR => old_value | oparg as u32,
+        FUTEX_OP_ANDN => old_value & !(oparg as u32),
+        FUTEX_OP_XOR => old_value ^ oparg as u32,
+        _ => return Err(AxError::Unsupported),
+    };
+    Ok(new_value)
+}
+
+fn compare_futex_wake_op(old_value: u32, raw_cmp: u32, cmparg: i32) -> AxResult<bool> {
+    let old_value = old_value as i32;
+    let matched = match raw_cmp {
+        FUTEX_OP_CMP_EQ => old_value == cmparg,
+        FUTEX_OP_CMP_NE => old_value != cmparg,
+        FUTEX_OP_CMP_LT => old_value < cmparg,
+        FUTEX_OP_CMP_LE => old_value <= cmparg,
+        FUTEX_OP_CMP_GT => old_value > cmparg,
+        FUTEX_OP_CMP_GE => old_value >= cmparg,
+        _ => return Err(AxError::Unsupported),
+    };
+    Ok(matched)
+}
+
+fn futex_atomic_op_in_user(uaddr: *mut u32, encoded_op: u32) -> AxResult<bool> {
+    if !uaddr.addr().is_multiple_of(align_of::<u32>()) {
+        return Err(AxError::InvalidInput);
+    }
+
+    let raw_op = (encoded_op >> 28) & 0xf;
+    let raw_cmp = (encoded_op >> 24) & 0xf;
+    let oparg = futex_wake_op_arg(raw_op, encoded_op);
+    let cmparg = sign_extend_12(encoded_op & 0xfff);
+
+    let old_value = uaddr.vm_read()?;
+    let new_value = apply_futex_wake_op(old_value, raw_op, oparg)?;
+    uaddr.vm_write(new_value)?;
+    compare_futex_wake_op(old_value, raw_cmp, cmparg)
+}
+
 fn parse_futex_op(futex_op: u32) -> AxResult<ParsedFutexOp> {
     let flags = futex_op & !FUTEX_COMMAND_MASK;
     if flags & !SUPPORTED_FLAGS != 0 {
@@ -63,10 +121,14 @@ fn parse_futex_op(futex_op: u32) -> AxResult<ParsedFutexOp> {
         FUTEX_WAKE_BITSET => FutexCommand::WakeBitset,
         FUTEX_REQUEUE => FutexCommand::Requeue,
         FUTEX_CMP_REQUEUE => FutexCommand::CmpRequeue,
+        FUTEX_WAKE_OP => FutexCommand::WakeOp,
         _ => return Err(AxError::Unsupported),
     };
 
     let clock_realtime = flags & FUTEX_CLOCK_REALTIME != 0;
+    if clock_realtime && command == FutexCommand::WakeOp {
+        return Err(AxError::Unsupported);
+    }
     if clock_realtime && !matches!(command, FutexCommand::Wait | FutexCommand::WaitBitset) {
         return Err(AxError::InvalidInput);
     }
@@ -219,6 +281,28 @@ pub fn sys_futex(
                 return Err(AxError::WouldBlock);
             };
 
+            if count > 0 {
+                ax_task::yield_now();
+            }
+            Ok(count as _)
+        }
+        FutexCommand::WakeOp => {
+            let wake_count = value as usize;
+            let wake2_count = timeout.addr();
+            validate_futex_word(uaddr)?;
+
+            let key2 = FutexKey::new_current(uaddr2.addr(), op.key_mode);
+            let table2 = futex_table_for(&key2);
+            let wake_second = futex_atomic_op_in_user(uaddr2, value3)?;
+
+            let mut count = 0;
+            if let Some(futex) = futex_table.get(&key) {
+                count += futex.wq.wake(wake_count, u32::MAX);
+            }
+            if wake_second && let Some(futex) = table2.get(&key2) {
+                count += futex.wq.wake(wake2_count, u32::MAX);
+            }
+
             if count > 0 {
                 ax_task::yield_now();
             }

test-suit/starryos/normal/qemu-smp1/syscall/test-futex-wake-op/c/CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.20)
+project(test-futex-wake-op C)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+set(CMAKE_C_EXTENSIONS OFF)
+
+add_executable(test-futex-wake-op src/main.c)
+target_include_directories(
+    test-futex-wake-op
+    PRIVATE
+    src
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../common
+)
+target_compile_options(test-futex-wake-op PRIVATE -Wall -Wextra -Werror)
+target_link_libraries(test-futex-wake-op PRIVATE pthread)
+
+install(TARGETS test-futex-wake-op RUNTIME DESTINATION usr/bin/starry-test-suit)