lldb/source/Host/linux/LibcGlue.cpp

   1 //===-- LibcGlue.cpp ------------------------------------------------------===//
   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 // This file adds functions missing from libc on older versions of linux
  10
  11 #include <cerrno>
  12 #include <lldb/Host/linux/Uio.h>
  13 #include <sys/syscall.h>
  14 #include <unistd.h>
  15
  16 #if !HAVE_PROCESS_VM_READV
  17 // If the syscall wrapper is not available, provide one.
  18 ssize_t process_vm_readv(::pid_t pid, const struct iovec *local_iov,
  19                          unsigned long liovcnt, const struct iovec *remote_iov,
  20                          unsigned long riovcnt, unsigned long flags) {
  21 #if HAVE_NR_PROCESS_VM_READV
  22   // If we have the syscall number, we can issue the syscall ourselves.
  23   return syscall(__NR_process_vm_readv, pid, local_iov, liovcnt, remote_iov,
  24                  riovcnt, flags);
  25 #else // If not, let's pretend the syscall is not present.
  26   errno = ENOSYS;
  27   return -1;
  28 #endif
  29 }
  30 #endif