| 1 | //===-- Linux implementation of read --------------------------------------===// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "src/unistd/read.h" |
| 10 | |
| 11 | #include "src/__support/OSUtil/syscall.h" // For internal syscall function. |
| 12 | #include "src/__support/common.h" |
| 13 | #include "src/__support/macros/sanitizer.h" // for MSAN_UNPOISON |
| 14 | #include "src/errno/libc_errno.h" |
| 15 | #include <sys/syscall.h> // For syscall numbers. |
| 16 | |
| 17 | namespace LIBC_NAMESPACE { |
| 18 | |
| 19 | LLVM_LIBC_FUNCTION(ssize_t, read, (int fd, void *buf, size_t count)) { |
| 20 | ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_read, ts: fd, ts: buf, ts: count); |
| 21 | if (ret < 0) { |
| 22 | libc_errno = static_cast<int>(-ret); |
| 23 | return -1; |
| 24 | } |
| 25 | // The cast is important since there is a check that dereferences the pointer |
| 26 | // which fails on void*. |
| 27 | MSAN_UNPOISON(reinterpret_cast<char *>(buf), count); |
| 28 | return ret; |
| 29 | } |
| 30 | |
| 31 | } // namespace LIBC_NAMESPACE |
| 32 |