1//===-- Linux implementation of sigaction ---------------------------------===//
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/signal/sigaction.h"
10
11#include "hdr/types/sigset_t.h"
12#include "src/__support/common.h"
13#include "src/__support/libc_errno.h"
14#include "src/__support/macros/config.h"
15#include "src/signal/linux/signal_utils.h"
16
17namespace LIBC_NAMESPACE_DECL {
18
19// TOOD: Some architectures will have their signal trampoline functions in the
20// vdso, use those when available.
21
22extern "C" void __restore_rt();
23
24LLVM_LIBC_FUNCTION(int, sigaction,
25 (int signal, const struct sigaction *__restrict libc_new,
26 struct sigaction *__restrict libc_old)) {
27 KernelSigaction kernel_new;
28 if (libc_new) {
29 kernel_new = *libc_new;
30 if (!(kernel_new.sa_flags & SA_RESTORER)) {
31 kernel_new.sa_flags |= SA_RESTORER;
32 kernel_new.sa_restorer = __restore_rt;
33 }
34 }
35
36 KernelSigaction kernel_old;
37 int ret = LIBC_NAMESPACE::syscall_impl<int>(
38 SYS_rt_sigaction, signal, libc_new ? &kernel_new : nullptr,
39 libc_old ? &kernel_old : nullptr, sizeof(sigset_t));
40 if (ret) {
41 libc_errno = -ret;
42 return -1;
43 }
44
45 if (libc_old)
46 *libc_old = kernel_old;
47 return 0;
48}
49
50} // namespace LIBC_NAMESPACE_DECL
51

source code of libc/src/signal/linux/sigaction.cpp