Consolidate relibc overlay patch chain

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

local/patches/relibc/P3-eventfd.patch

@@ -1,115 +0,0 @@
-diff -ruN a/src/header/mod.rs b/src/header/mod.rs
---- a/src/header/mod.rs	2026-04-15 09:40:30.417847129 +0100
-+++ b/src/header/mod.rs	2026-04-15 09:46:42.009254774 +0100
-@@ -89,6 +89,7 @@
- // TODO: stropts.h (deprecated)
- pub mod sys_auxv;
- pub mod sys_epoll;
-+pub mod sys_eventfd;
- pub mod sys_file;
- pub mod sys_ioctl;
- // TODO: sys/ipc.h
-diff -ruN a/src/header/sys_eventfd/cbindgen.toml b/src/header/sys_eventfd/cbindgen.toml
---- a/src/header/sys_eventfd/cbindgen.toml	1970-01-01 00:00:00.000000000 +0000
-+++ b/src/header/sys_eventfd/cbindgen.toml	2026-04-15 09:46:42.009280833 +0100
-@@ -0,0 +1,9 @@
-+sys_includes = ["stdint.h"]
-+include_guard = "_SYS_EVENTFD_H"
-+language = "C"
-+style = "Tag"
-+no_includes = true
-+cpp_compat = true
-+
-+[enum]
-+prefix_with_name = true
-diff -ruN a/src/header/sys_eventfd/mod.rs b/src/header/sys_eventfd/mod.rs
---- a/src/header/sys_eventfd/mod.rs	1970-01-01 00:00:00.000000000 +0000
-+++ b/src/header/sys_eventfd/mod.rs	2026-04-15 09:46:42.009305629 +0100
-@@ -0,0 +1,87 @@
-+//! `sys/eventfd.h` implementation.
-+//!
-+//! Non-POSIX, see <https://man7.org/linux/man-pages/man2/eventfd.2.html>.
-+
-+use core::{mem, slice};
-+
-+use crate::{
-+    c_str::{CStr, CString},
-+    error::{Errno, ResultExt},
-+    header::{
-+        errno::{EFAULT, EINVAL, EIO},
-+        fcntl::{O_CLOEXEC, O_NONBLOCK, O_RDWR},
-+    },
-+    platform::{
-+        ERRNO, Pal, Sys,
-+        types::{c_int, c_uint},
-+    },
-+};
-+
-+pub const EFD_CLOEXEC: c_int = 0x80000;
-+pub const EFD_NONBLOCK: c_int = 0x800;
-+pub const EFD_SEMAPHORE: c_int = 0x1;
-+pub type eventfd_t = u64;
-+
-+fn read_exact(fd: c_int, buf: &mut [u8]) -> Result<(), Errno> {
-+    match Sys::read(fd, buf)? {
-+        n if n == buf.len() => Ok(()),
-+        _ => Err(Errno(EIO)),
-+    }
-+}
-+
-+fn write_exact(fd: c_int, buf: &[u8]) -> Result<(), Errno> {
-+    match Sys::write(fd, buf)? {
-+        n if n == buf.len() => Ok(()),
-+        _ => Err(Errno(EIO)),
-+    }
-+}
-+
-+fn eventfd2_inner(initval: c_uint, flags: c_int) -> Result<c_int, Errno> {
-+    let supported = EFD_CLOEXEC | EFD_NONBLOCK | EFD_SEMAPHORE;
-+    if flags & !supported != 0 {
-+        return Err(Errno(EINVAL));
-+    }
-+
-+    let mut oflag = O_RDWR;
-+    if flags & EFD_CLOEXEC == EFD_CLOEXEC {
-+        oflag |= O_CLOEXEC;
-+    }
-+    if flags & EFD_NONBLOCK == EFD_NONBLOCK {
-+        oflag |= O_NONBLOCK;
-+    }
-+
-+    let path = CString::new(format!(
-+        "/scheme/event/eventfd/{}/{}",
-+        initval,
-+        if flags & EFD_SEMAPHORE == EFD_SEMAPHORE { 1 } else { 0 }
-+    ))
-+    .map_err(|_| Errno(EINVAL))?;
-+
-+    Sys::open(CStr::borrow(&path), oflag, 0)
-+}
-+
-+#[unsafe(no_mangle)]
-+pub extern "C" fn eventfd2(initval: c_uint, flags: c_int) -> c_int {
-+    eventfd2_inner(initval, flags).or_minus_one_errno()
-+}
-+
-+#[unsafe(no_mangle)]
-+pub extern "C" fn eventfd(initval: c_uint, flags: c_int) -> c_int {
-+    eventfd2(initval, flags)
-+}
-+
-+#[unsafe(no_mangle)]
-+pub unsafe extern "C" fn eventfd_read(fd: c_int, value: *mut eventfd_t) -> c_int {
-+    if value.is_null() {
-+        ERRNO.set(EFAULT);
-+        return -1;
-+    }
-+    let buf = unsafe { slice::from_raw_parts_mut(value.cast::<u8>(), mem::size_of::<eventfd_t>()) };
-+    read_exact(fd, buf).map(|()| 0).or_minus_one_errno()
-+}
-+
-+#[unsafe(no_mangle)]
-+pub unsafe extern "C" fn eventfd_write(fd: c_int, value: eventfd_t) -> c_int {
-+    let buf = unsafe { slice::from_raw_parts((&raw const value).cast::<u8>(), mem::size_of::<eventfd_t>()) };
-+    write_exact(fd, buf).map(|()| 0).or_minus_one_errno()
-+}

local/patches/relibc/P3-fcntl-dupfd-cloexec.patch

@@ -1,25 +1,29 @@
 diff --git a/src/header/fcntl/mod.rs b/src/header/fcntl/mod.rs
 --- a/src/header/fcntl/mod.rs
 +++ b/src/header/fcntl/mod.rs
-@@ -8,7 +8,8 @@
+@@ -8,6 +8,7 @@ use crate::{
      c_str::CStr,
-     error::ResultExt,
-+    header::unistd::{close, dup},
+     error::{Errno, ResultExt},
+     header::errno::ENAMETOOLONG,
++    header::unistd::close,
      platform::{
          Pal, Sys,
-         types::{c_char, c_int, c_short, c_ulonglong, mode_t, off_t, pid_t},
-     },
- };
-@@ -74,5 +75,17 @@
+         types::{
+@@ -78,6 +79,23 @@ pub unsafe extern "C" fn fcntl(fildes: c_int, cmd: c_int, mut __valist: ...) ->
          _ => 0,
      };
  
 +    if cmd == F_DUPFD_CLOEXEC {
-+        let new_fd = dup(fildes);
++        let new_fd = Sys::fcntl(fildes, F_DUPFD_CLOEXEC, arg).or_minus_one_errno();
++        if new_fd >= 0 {
++            return new_fd;
++        }
++
++        let new_fd = Sys::fcntl(fildes, F_DUPFD, arg).or_minus_one_errno();
 +        if new_fd < 0 {
 +            return -1;
 +        }
-+        if unsafe { fcntl(new_fd, F_SETFD, FD_CLOEXEC as c_ulonglong) } < 0 {
++        if Sys::fcntl(new_fd, F_SETFD, FD_CLOEXEC as c_ulonglong).or_minus_one_errno() < 0 {
 +            let _ = close(new_fd);
 +            return -1;
 +        }

local/patches/relibc/P3-fd-event-tests.patch

@@ -1,114 +1,3 @@
-diff --git a/tests/sys_eventfd/eventfd.c b/tests/sys_eventfd/eventfd.c
-new file mode 100644
---- /dev/null
-+++ b/tests/sys_eventfd/eventfd.c
-@@ -0,0 +1,27 @@
-+#include <assert.h>
-+#include <stdint.h>
-+#include <stdio.h>
-+#include <sys/eventfd.h>
-+#include <unistd.h>
-+
-+int main(void) {
-+    int fd = eventfd(2, 0);
-+    assert(fd >= 0);
-+    eventfd_t value = 0;
-+    assert(eventfd_read(fd, &value) == 0);
-+    assert(value == 2);
-+    assert(eventfd_write(fd, 5) == 0);
-+    assert(eventfd_read(fd, &value) == 0);
-+    assert(value == 5);
-+    assert(close(fd) == 0);
-+
-+    int semfd = eventfd(2, EFD_SEMAPHORE);
-+    assert(semfd >= 0);
-+    assert(eventfd_read(semfd, &value) == 0);
-+    assert(value == 1);
-+    assert(eventfd_read(semfd, &value) == 0);
-+    assert(value == 1);
-+    assert(close(semfd) == 0);
-+    puts("eventfd ok");
-+    return 0;
-+}
-diff --git a/tests/sys_signalfd/signalfd.c b/tests/sys_signalfd/signalfd.c
-new file mode 100644
---- /dev/null
-+++ b/tests/sys_signalfd/signalfd.c
-@@ -0,0 +1,23 @@
-+#include <assert.h>
-+#include <signal.h>
-+#include <stdio.h>
-+#include <stdint.h>
-+#include <sys/signalfd.h>
-+#include <unistd.h>
-+
-+int main(void) {
-+    sigset_t mask;
-+    assert(sigemptyset(&mask) == 0);
-+    assert(sigaddset(&mask, SIGUSR1) == 0);
-+    assert(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
-+    int fd = signalfd(-1, &mask, sizeof(mask));
-+    assert(fd >= 0);
-+    assert(kill(getpid(), SIGUSR1) == 0);
-+    struct signalfd_siginfo info;
-+    assert(read(fd, &info, sizeof(info)) == (ssize_t)sizeof(info));
-+    assert(info.ssi_signo == SIGUSR1);
-+    assert(info.ssi_pid == (uint32_t)getpid());
-+    assert(close(fd) == 0);
-+    puts("signalfd ok");
-+    return 0;
-+}
-diff --git a/tests/sys_signalfd/header_only.c b/tests/sys_signalfd/header_only.c
-new file mode 100644
---- /dev/null
-+++ b/tests/sys_signalfd/header_only.c
-@@ -0,0 +1,12 @@
-+#include <stdint.h>
-+#include <sys/signalfd.h>
-+
-+int main(void) {
-+    struct signalfd_siginfo info = {0};
-+    int (*fn1)(int, const sigset_t *, size_t) = signalfd;
-+    int (*fn2)(int, const sigset_t *, size_t, int) = signalfd4;
-+
-+    return (int)sizeof(info)
-+        + (fn1 == 0)
-+        + (fn2 == 0);
-+}
-diff --git a/tests/sys_timerfd/timerfd.c b/tests/sys_timerfd/timerfd.c
-new file mode 100644
---- /dev/null
-+++ b/tests/sys_timerfd/timerfd.c
-@@ -0,0 +1,29 @@
-+#include <assert.h>
-+#include <stdint.h>
-+#include <stdio.h>
-+#include <string.h>
-+#include <sys/timerfd.h>
-+#include <unistd.h>
-+
-+int main(void) {
-+    int fd = timerfd_create(CLOCK_REALTIME, 0);
-+    assert(fd >= 0);
-+    struct itimerspec spec;
-+    memset(&spec, 0, sizeof(spec));
-+    spec.it_value.tv_nsec = 1000000;
-+    assert(timerfd_settime(fd, 0, &spec, NULL) == 0);
-+
-+    uint64_t expirations = 0;
-+    assert(read(fd, &expirations, sizeof(expirations)) == (ssize_t)sizeof(expirations));
-+    assert(expirations >= 1);
-+
-+    struct itimerspec cur;
-+    assert(timerfd_gettime(fd, &cur) == 0);
-+
-+    memset(&spec, 0, sizeof(spec));
-+    spec.it_value.tv_sec = 1;
-+    assert(timerfd_settime(fd, TFD_TIMER_ABSTIME, &spec, NULL) == 0);
-+    assert(close(fd) == 0);
-+    puts("timerfd ok");
-+    return 0;
-+}
 diff --git a/tests/Makefile.tests.mk b/tests/Makefile.tests.mk
 --- a/tests/Makefile.tests.mk
 +++ b/tests/Makefile.tests.mk

local/patches/relibc/redox.patch

@@ -17,18 +17,18 @@ index 62e98108..a9c72392 100644
      return (double)(*val);
  }
 diff --git a/src/header/fcntl/mod.rs b/src/header/fcntl/mod.rs
-index 6a4db2fa..82484375 100644
+index ec37906c..95604e06 100644
 --- a/src/header/fcntl/mod.rs
 +++ b/src/header/fcntl/mod.rs
-@@ -7,6 +7,7 @@ use core::num::NonZeroU64;
- use crate::{
+@@ -8,6 +8,7 @@ use crate::{
      c_str::CStr,
-     error::ResultExt,
+     error::{Errno, ResultExt},
+     header::errno::ENAMETOOLONG,
 +    header::unistd::close,
      platform::{
          Pal, Sys,
-         types::{c_char, c_int, c_short, c_ulonglong, mode_t, off_t, pid_t},
-@@ -74,5 +75,22 @@ pub unsafe extern "C" fn fcntl(fildes: c_int, cmd: c_int, mut __valist: ...) ->
+         types::{
+@@ -78,6 +79,23 @@ pub unsafe extern "C" fn fcntl(fildes: c_int, cmd: c_int, mut __valist: ...) ->
          _ => 0,
      };
  
@@ -51,17 +51,3 @@ index 6a4db2fa..82484375 100644
 +
      Sys::fcntl(fildes, cmd, arg).or_minus_one_errno()
  }
-diff --git a/src/header/fcntl/linux.rs b/src/header/fcntl/linux.rs
-index 9a3978dc..906ad525 100644
---- a/src/header/fcntl/linux.rs
-+++ b/src/header/fcntl/linux.rs
-@@ -15,7 +15,7 @@ pub const O_DIRECTORY: c_int = 0x1_0000;
- pub const O_NOFOLLOW: c_int = 0x2_0000;
- pub const O_CLOEXEC: c_int = 0x8_0000;
- pub const O_PATH: c_int = 0x20_0000;
- 
--pub const FD_CLOEXEC: c_int = 0x8_0000;
-+pub const FD_CLOEXEC: c_int = 1;
- 
- // Defined for compatibility
- pub const O_NDELAY: c_int = O_NONBLOCK;

recipes/core/relibc/recipe.toml

@@ -3,7 +3,6 @@ git = "https://gitlab.redox-os.org/redox-os/relibc.git"
 patches = [
     "../../../local/patches/relibc/redox.patch",
     "../../../local/patches/relibc/P0-strtold-cpp-linkage-and-compat.patch",
-    "../../../local/patches/relibc/P3-eventfd.patch",
     "../../../local/patches/relibc/P3-signalfd.patch",
     "../../../local/patches/relibc/P3-signalfd-header.patch",
     "../../../local/patches/relibc/P3-timerfd.patch",