From 84745e1eb25c369611aaab9d9041e76b9e1613c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 13 Oct 2026 20:45:29 +0200
Subject: [PATCH] std.c: fix mremap() signature for serenity

---
 lib/std/c.zig          | 6 +++++-
 lib/std/c/serenity.zig | 5 +++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/std/c.zig b/lib/std/c.zig
index 556d2124168b81b44436530988bf49f99c683679..7a9b706d0a06ab0fd51a40634ed3fbf92a36d28b 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -10905,7 +10905,10 @@ pub extern "c" fn write(fd: fd_t, buf: [*]const u8, nbyte: usize) isize;
 pub extern "c" fn pwrite(fd: fd_t, buf: [*]const u8, nbyte: usize, offset: off_t) isize;
 pub extern "c" fn mmap(addr: ?*align(page_size) anyopaque, len: usize, prot: PROT, flags: MAP, fd: fd_t, offset: off_t) *anyopaque;
 pub extern "c" fn munmap(addr: *align(page_size) const anyopaque, len: usize) c_int;
-pub extern "c" fn mremap(addr: ?*align(page_size) const anyopaque, old_len: usize, new_len: usize, flags: MREMAP, ...) *anyopaque;
+pub const mremap = switch (native_os) {
+    .serenity => serenity.mremap,
+    else => private.mremap,
+};
 pub extern "c" fn mprotect(addr: *align(page_size) anyopaque, len: usize, prot: PROT) c_int;
 pub extern "c" fn link(oldpath: [*:0]const u8, newpath: [*:0]const u8) c_int;
 pub extern "c" fn linkat(oldfd: fd_t, oldpath: [*:0]const u8, newfd: fd_t, newpath: [*:0]const u8, flags: c_uint) c_int;
@@ -11849,6 +11852,7 @@ const private = struct {
     extern "c" fn gettimeofday(noalias tv: ?*timeval, noalias tz: ?*timezone) c_int;
     extern "c" fn ioctl(fd: fd_t, request: c_int, ...) c_int;
     extern "c" fn msync(addr: *align(page_size) const anyopaque, len: usize, flags: c_int) c_int;
+    extern "c" fn mremap(addr: ?*align(page_size) const anyopaque, old_len: usize, new_len: usize, flags: MREMAP, ...) *anyopaque;
     extern "c" fn nanosleep(rqtp: *const timespec, rmtp: ?*timespec) c_int;
     extern "c" fn pipe2(fds: *[2]fd_t, flags: O) c_int;
     extern "c" fn readdir(dir: *DIR) ?*dirent;
diff --git a/lib/std/c/serenity.zig b/lib/std/c/serenity.zig
index d391f9d82ce080b9b9e602e8bf75865290e47ae4..eb416e7f18a7756725d3e1b10da028045da99fe8 100644
--- a/lib/std/c/serenity.zig
+++ b/lib/std/c/serenity.zig
@@ -1,10 +1,12 @@
 const std = @import("../std.zig");
 const assert = std.debug.assert;
 const builtin = @import("builtin");
+const MAP = std.c.MAP;
 const O = std.c.O;
 const clockid_t = std.c.clockid_t;
 const pid_t = std.c.pid_t;
 const timespec = std.c.timespec;
+const page_size = std.heap.page_size_min;
 
 comptime {
     assert(builtin.os.tag == .serenity); // Prevent access of std.c symbols on wrong OS.
@@ -68,6 +70,9 @@ pub extern "c" fn anon_create(size: usize, options: O) c_int;
 pub extern "c" fn getkeymap(name_buffer: [*]u8, name_buffer_size: usize, map: [*]u32, shift_map: [*]u32, alt_map: [*]u32, altgr_map: [*]u32, shift_altgr_map: [*]u32) c_int;
 pub extern "c" fn setkeymap(name: [*]const u8, map: [*]const u32, shift_map: [*]const u32, alt_map: [*]const u32, altgr_map: [*]const u32, shift_altgr_map: [*]const u32) c_int;
 
+// https://github.com/SerenityOS/serenity/blob/fe4f3879551f2fdd8a24de06b88f4450e2f3b93d/Userland/Libraries/LibC/sys/mman.h#L17
+pub extern "c" fn mremap(old_address: ?*align(page_size) anyopaque, old_size: usize, new_size: usize, flags: MAP) *anyopaque;
+
 // https://github.com/SerenityOS/serenity/blob/5bd8af99be0bc4b2e14f361fd7d7590e6bcfa4d6/Kernel/API/POSIX/netinet/in.h#L29
 pub const IP = struct {
     pub const TOS = 1;
-- 
2.54.0