xref: /aosp_15_r20/external/llvm-libc/src/sys/epoll/linux/epoll_pwait.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===---------- Linux implementation of the epoll_pwait function ----------===//
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/sys/epoll/epoll_pwait.h"
10 
11 #include "hdr/signal_macros.h" // for NSIG
12 #include "hdr/types/sigset_t.h"
13 #include "hdr/types/struct_epoll_event.h"
14 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
15 #include "src/__support/common.h"
16 #include "src/__support/macros/config.h"
17 #include "src/__support/macros/sanitizer.h"
18 #include "src/errno/libc_errno.h"
19 
20 #include <sys/syscall.h> // For syscall numbers.
21 
22 namespace LIBC_NAMESPACE_DECL {
23 
24 LLVM_LIBC_FUNCTION(int, epoll_pwait,
25                    (int epfd, struct epoll_event *events, int maxevents,
26                     int timeout, const sigset_t *sigmask)) {
27   int ret = LIBC_NAMESPACE::syscall_impl<int>(
28       SYS_epoll_pwait, epfd, reinterpret_cast<long>(events), maxevents, timeout,
29       reinterpret_cast<long>(sigmask), NSIG / 8);
30 
31   // A negative return value indicates an error with the magnitude of the
32   // value being the error code.
33   if (ret < 0) {
34     libc_errno = -ret;
35     return -1;
36   }
37 
38   MSAN_UNPOISON(events, ret * sizeof(struct epoll_event));
39 
40   return ret;
41 }
42 
43 } // namespace LIBC_NAMESPACE_DECL
44