diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig index 719e541846..79f9ba9c95 100644 --- a/lib/std/os/linux.zig +++ b/lib/std/os/linux.zig @@ -350,7 +350,13 @@ pub fn pread(fd: i32, buf: [*]u8, count: usize, offset: u64) usize { ); } } else { - return syscall4(SYS_pread, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count, offset); + return syscall4( + SYS_pread, + @bitCast(usize, @as(isize, fd)), + @ptrToInt(buf), + count, + offset, + ); } } @@ -385,7 +391,36 @@ pub fn write(fd: i32, buf: [*]const u8, count: usize) usize { } pub fn pwrite(fd: i32, buf: [*]const u8, count: usize, offset: usize) usize { - return syscall4(SYS_pwrite, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count, offset); + if (@hasDecl(@This(), "SYS_pwrite64")) { + if (require_aligned_register_pair) { + return syscall6( + SYS_pwrite64, + @bitCast(usize, @as(isize, fd)), + @ptrToInt(buf), + count, + 0, + @truncate(usize, offset), + @truncate(usize, offset >> 32), + ); + } else { + return syscall5( + SYS_pwrite64, + @bitCast(usize, @as(isize, fd)), + @ptrToInt(buf), + count, + @truncate(usize, offset), + @truncate(usize, offset >> 32), + ); + } + } else { + return syscall4( + SYS_pwrite, + @bitCast(usize, @as(isize, fd)), + @ptrToInt(buf), + count, + offset, + ); + } } pub fn rename(old: [*:0]const u8, new: [*:0]const u8) usize {