47 lines · cpp
1//===-- Linux implementation of sigaltstack -------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/signal/sigaltstack.h"10#include "hdr/types/stack_t.h"11#include "src/__support/libc_errno.h"12#include "src/__support/macros/config.h"13#include "src/signal/linux/signal_utils.h"14 15#include "src/__support/common.h"16 17#include <sys/syscall.h>18 19namespace LIBC_NAMESPACE_DECL {20 21LLVM_LIBC_FUNCTION(int, sigaltstack,22 (const stack_t *__restrict ss, stack_t *__restrict oss)) {23 if (ss != nullptr) {24 unsigned not_ss_disable = ~unsigned(SS_DISABLE);25 if ((unsigned(ss->ss_flags) & not_ss_disable) != 0) {26 // Flags cannot have anything other than SS_DISABLE set.27 // We do the type-casting to unsigned because the |ss_flags|28 // field of stack_t is of type "int".29 libc_errno = EINVAL;30 return -1;31 }32 if (ss->ss_size < MINSIGSTKSZ) {33 libc_errno = ENOMEM;34 return -1;35 }36 }37 38 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sigaltstack, ss, oss);39 if (ret < 0) {40 libc_errno = -ret;41 return -1;42 }43 return 0;44}45 46} // namespace LIBC_NAMESPACE_DECL47