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