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/macros/config.h" 14 #include "src/errno/libc_errno.h" 15 #include "src/signal/linux/signal_utils.h" 16 17 namespace LIBC_NAMESPACE_DECL { 18 19 // TOOD: Some architectures will have their signal trampoline functions in the 20 // vdso, use those when available. 21 22 extern "C" void __restore_rt(); 23 24 LLVM_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