Do not silently truncate offsets for read_at/write_at on emscripten

Generate an IO error if the offset is out of bounds for the system call.
This commit is contained in:
Tobias Bucher 2018-05-12 02:31:38 +02:00
parent 9e3caa23f9
commit 4ce24269bb

View File

@ -75,8 +75,15 @@ impl FileDesc {
unsafe fn cvt_pread64(fd: c_int, buf: *mut c_void, count: usize, offset: i64)
-> io::Result<isize>
{
use convert::TryInto;
use libc::pread64;
cvt(pread64(fd, buf, count, offset as i32))
// pread64 on emscripten actually takes a 32 bit offset
if let Ok(o) = offset.try_into() {
cvt(pread64(fd, buf, count, o))
} else {
Err(io::Error::new(io::ErrorKind::InvalidInput,
"cannot pread >2GB"))
}
}
#[cfg(not(any(target_os = "android", target_os = "emscripten")))]
@ -116,8 +123,15 @@ impl FileDesc {
unsafe fn cvt_pwrite64(fd: c_int, buf: *const c_void, count: usize, offset: i64)
-> io::Result<isize>
{
use convert::TryInto;
use libc::pwrite64;
cvt(pwrite64(fd, buf, count, offset as i32))
// pwrite64 on emscripten actually takes a 32 bit offset
if let Ok(o) = offset.try_into() {
cvt(pwrite64(fd, buf, count, o))
} else {
Err(io::Error::new(io::ErrorKind::InvalidInput,
"cannot pwrite >2GB"))
}
}
#[cfg(not(any(target_os = "android", target_os = "emscripten")))]