1*71db0c75SAndroid Build Coastguard Worker //===-- Linux implementation of sigaltstack -------------------------------===// 2*71db0c75SAndroid Build Coastguard Worker // 3*71db0c75SAndroid Build Coastguard Worker // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*71db0c75SAndroid Build Coastguard Worker // See https://llvm.org/LICENSE.txt for license information. 5*71db0c75SAndroid Build Coastguard Worker // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*71db0c75SAndroid Build Coastguard Worker // 7*71db0c75SAndroid Build Coastguard Worker //===----------------------------------------------------------------------===// 8*71db0c75SAndroid Build Coastguard Worker 9*71db0c75SAndroid Build Coastguard Worker #include "src/signal/sigaltstack.h" 10*71db0c75SAndroid Build Coastguard Worker #include "hdr/types/stack_t.h" 11*71db0c75SAndroid Build Coastguard Worker #include "src/__support/macros/config.h" 12*71db0c75SAndroid Build Coastguard Worker #include "src/errno/libc_errno.h" 13*71db0c75SAndroid Build Coastguard Worker #include "src/signal/linux/signal_utils.h" 14*71db0c75SAndroid Build Coastguard Worker 15*71db0c75SAndroid Build Coastguard Worker #include "src/__support/common.h" 16*71db0c75SAndroid Build Coastguard Worker 17*71db0c75SAndroid Build Coastguard Worker #include <sys/syscall.h> 18*71db0c75SAndroid Build Coastguard Worker 19*71db0c75SAndroid Build Coastguard Worker namespace LIBC_NAMESPACE_DECL { 20*71db0c75SAndroid Build Coastguard Worker 21*71db0c75SAndroid Build Coastguard Worker LLVM_LIBC_FUNCTION(int, sigaltstack, 22*71db0c75SAndroid Build Coastguard Worker (const stack_t *__restrict ss, stack_t *__restrict oss)) { 23*71db0c75SAndroid Build Coastguard Worker if (ss != nullptr) { 24*71db0c75SAndroid Build Coastguard Worker unsigned not_ss_disable = ~unsigned(SS_DISABLE); 25*71db0c75SAndroid Build Coastguard Worker if ((unsigned(ss->ss_flags) & not_ss_disable) != 0) { 26*71db0c75SAndroid Build Coastguard Worker // Flags cannot have anything other than SS_DISABLE set. 27*71db0c75SAndroid Build Coastguard Worker // We do the type-casting to unsigned because the |ss_flags| 28*71db0c75SAndroid Build Coastguard Worker // field of stack_t is of type "int". 29*71db0c75SAndroid Build Coastguard Worker libc_errno = EINVAL; 30*71db0c75SAndroid Build Coastguard Worker return -1; 31*71db0c75SAndroid Build Coastguard Worker } 32*71db0c75SAndroid Build Coastguard Worker if (ss->ss_size < MINSIGSTKSZ) { 33*71db0c75SAndroid Build Coastguard Worker libc_errno = ENOMEM; 34*71db0c75SAndroid Build Coastguard Worker return -1; 35*71db0c75SAndroid Build Coastguard Worker } 36*71db0c75SAndroid Build Coastguard Worker } 37*71db0c75SAndroid Build Coastguard Worker 38*71db0c75SAndroid Build Coastguard Worker int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sigaltstack, ss, oss); 39*71db0c75SAndroid Build Coastguard Worker if (ret < 0) { 40*71db0c75SAndroid Build Coastguard Worker libc_errno = -ret; 41*71db0c75SAndroid Build Coastguard Worker return -1; 42*71db0c75SAndroid Build Coastguard Worker } 43*71db0c75SAndroid Build Coastguard Worker return 0; 44*71db0c75SAndroid Build Coastguard Worker } 45*71db0c75SAndroid Build Coastguard Worker 46*71db0c75SAndroid Build Coastguard Worker } // namespace LIBC_NAMESPACE_DECL 47