Implement read_buf and vectored read/write for SGX stdio

Author: thaliaarchi

library/std/src/sys/pal/sgx/abi/usercalls/mod.rs

@@ -1,5 +1,7 @@
 usecrate::cmp;
-usecrate::io::{ErrorasIoError,ErrorKind,IoSlice,IoSliceMut,ResultasIoResult};
+usecrate::io::{
+BorrowedCursor,ErrorasIoError,ErrorKind,IoSlice,IoSliceMut,ResultasIoResult,
+};
 usecrate::random::{DefaultRandomSource,Random};
 usecrate::time::{Duration,Instant};
 
@@ -36,6 +38,19 @@ pub fn read(fd: Fd, bufs: &mut [IoSliceMut<'_>]) -> IoResult<usize> {
 }
 }
 
+/// Usercall `read` with an uninitialized buffer. See the ABI documentation for
+/// more information.
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pubfnread_buf(fd:Fd,mutbuf:BorrowedCursor<'_>) -> IoResult<()>{
+unsafe{
+letmut userbuf = alloc::User::<[u8]>::uninitialized(buf.capacity());
+let len = raw::read(fd, userbuf.as_mut_ptr().cast(), userbuf.len()).from_sgx_result()?;
+ userbuf[..len].copy_to_enclave(&mut buf.as_mut()[..len]);
+ buf.advance_unchecked(len);
+Ok(())
+}
+}
+
 /// Usercall `read_alloc`. See the ABI documentation for more information.
 #[unstable(feature = "sgx_platform", issue = "56975")]
 pubfnread_alloc(fd:Fd) -> IoResult<Vec<u8>>{

library/std/src/sys/pal/sgx/fd.rs

@@ -29,7 +29,7 @@ impl FileDesc {
 }
 
 pubfnread_buf(&self,buf:BorrowedCursor<'_>) -> io::Result<()>{
-crate::io::default_read_buf(|b| self.read(b), buf)
+usercalls::read_buf(self.fd, buf)
 }
 
 pubfnread_vectored(&self,bufs:&mut[IoSliceMut<'_>]) -> io::Result<usize>{

library/std/src/sys/stdio/sgx.rs

@@ -1,6 +1,6 @@
 use fortanix_sgx_abi as abi;
 
-usecrate::io;
+usecrate::io::{self,BorrowedCursor,IoSlice,IoSliceMut};
 usecrate::sys::fd::FileDesc;
 
 pubstructStdin(());
@@ -24,6 +24,19 @@ impl io::Read for Stdin {
 fnread(&mutself,buf:&mut[u8]) -> io::Result<usize>{
 with_std_fd(abi::FD_STDIN, |fd| fd.read(buf))
 }
+
+fnread_buf(&mutself,buf:BorrowedCursor<'_>) -> io::Result<()>{
+with_std_fd(abi::FD_STDIN, |fd| fd.read_buf(buf))
+}
+
+fnread_vectored(&mutself,bufs:&mut[IoSliceMut<'_>]) -> io::Result<usize>{
+with_std_fd(abi::FD_STDIN, |fd| fd.read_vectored(bufs))
+}
+
+#[inline]
+fnis_read_vectored(&self) -> bool{
+true
+}
 }
 
 implStdout{
@@ -40,6 +53,15 @@ impl io::Write for Stdout {
 fnflush(&mutself) -> io::Result<()>{
 with_std_fd(abi::FD_STDOUT, |fd| fd.flush())
 }
+
+fnwrite_vectored(&mutself,bufs:&[IoSlice<'_>]) -> io::Result<usize>{
+with_std_fd(abi::FD_STDOUT, |fd| fd.write_vectored(bufs))
+}
+
+#[inline]
+fnis_write_vectored(&self) -> bool{
+true
+}
 }
 
 implStderr{
@@ -56,6 +78,15 @@ impl io::Write for Stderr {
 fnflush(&mutself) -> io::Result<()>{
 with_std_fd(abi::FD_STDERR, |fd| fd.flush())
 }
+
+fnwrite_vectored(&mutself,bufs:&[IoSlice<'_>]) -> io::Result<usize>{
+with_std_fd(abi::FD_STDERR, |fd| fd.write_vectored(bufs))
+}
+
+#[inline]
+fnis_write_vectored(&self) -> bool{
+true
+}
 }
 
 pubconstSTDIN_BUF_SIZE:usize = crate::sys::io::DEFAULT_BUF_SIZE;