Merge pull request #1142 from Sonicadvance1/implement_base_signalfd

Linux: Implements a base implementation of signalfd{4,}

Source/Tests/LinuxSyscalls/SignalDelegator.cpp

@@ -19,6 +19,7 @@ desc: Handles host -> host and host -> guest signal routing, emulates procmask &
 #include <bits/types/stack_t.h>
 #include <sys/mman.h>
 #include <sys/syscall.h>
+#include <sys/signalfd.h>
 #include <unistd.h>
 
 namespace FEX::HLE {
@@ -688,4 +689,32 @@ namespace FEX::HLE {
 
     return Result == -1 ? -errno : Result;
   }
+
+  uint64_t SignalDelegator::GuestSignalFD(int fd, const uint64_t *set, size_t sigsetsize, int flags) {
+    if (sigsetsize > sizeof(uint64_t)) {
+      return -EINVAL;
+    }
+
+    sigset_t HostSet{};
+    sigemptyset(&HostSet);
+
+    for (size_t i = 0; i < MAX_SIGNALS; ++i) {
+      if (HostHandlers[i + 1].Required) {
+        // For now skip our internal signals
+        continue;
+      }
+
+      if (ThreadData.CurrentSignalMask.Val & (1ULL << i)) {
+        sigaddset(&HostSet, i + 1);
+      }
+    }
+
+    // XXX: This is a barebones implementation just to get applications that listen for SIGCHLD to work
+    // In the future we need our own listern thread that forwards the result
+    // Thread is necessary to prevent deadlocks for a thread that has signaled on the same thread listening to the FD and blocking is enabled
+    uint64_t Result = signalfd(fd, &HostSet, flags);
+
+    return Result == -1 ? -errno : Result;
+  }
+
 }

Source/Tests/LinuxSyscalls/SignalDelegator.h

@@ -83,6 +83,7 @@ namespace FEX::HLE {
     uint64_t GuestSigPending(uint64_t *set, size_t sigsetsize);
     uint64_t GuestSigSuspend(uint64_t *set, size_t sigsetsize);
     uint64_t GuestSigTimedWait(uint64_t *set, siginfo_t *info, const struct timespec *timeout, size_t sigsetsize);
+    uint64_t GuestSignalFD(int fd, const uint64_t *set, size_t sigsetsize , int flags);
 
     // Called from the thunk handler to handle the signal
     void HandleSignal(int Signal, void *Info, void *UContext);

Source/Tests/LinuxSyscalls/Syscalls/Signals.cpp

@@ -42,6 +42,14 @@ namespace FEX::HLE {
       SYSCALL_ERRNO();
     });
 
+    REGISTER_SYSCALL_IMPL(signalfd, [](FEXCore::Core::CpuStateFrame *Frame, int fd, const uint64_t *mask, size_t sigsetsize) -> uint64_t {
+      return FEX::HLE::_SyscallHandler->GetSignalDelegator()->GuestSignalFD(fd, mask, sigsetsize, 0);
+    });
+
+    REGISTER_SYSCALL_IMPL(signalfd4, [](FEXCore::Core::CpuStateFrame *Frame, int fd, const uint64_t *mask, size_t sigsetsize, int flags) -> uint64_t {
+      return FEX::HLE::_SyscallHandler->GetSignalDelegator()->GuestSignalFD(fd, mask, sigsetsize, flags);
+    });
+
     if (Handler->IsHostKernelVersionAtLeast(5, 1, 0)) {
       REGISTER_SYSCALL_IMPL(pidfd_send_signal, [](FEXCore::Core::CpuStateFrame *Frame, int pidfd, int sig, siginfo_t *info, unsigned int flags) -> uint64_t {
         uint64_t Result = ::syscall(SYS_pidfd_send_signal, pidfd, sig, info, flags);

Source/Tests/LinuxSyscalls/Syscalls/Stubs.cpp

@@ -52,14 +52,6 @@ namespace FEX::HLE {
       SYSCALL_STUB(restart_syscall);
     });
 
-    REGISTER_SYSCALL_IMPL(signalfd, [](FEXCore::Core::CpuStateFrame *Frame, int fd, const sigset_t *mask, size_t sizemask) -> uint64_t {
-      SYSCALL_STUB(signalfd);
-    });
-
-    REGISTER_SYSCALL_IMPL(signalfd4, [](FEXCore::Core::CpuStateFrame *Frame, int fd, const sigset_t *mask, size_t sizemask, int flags) -> uint64_t {
-      SYSCALL_STUB(signalfd4);
-    });
-
     REGISTER_SYSCALL_IMPL(rt_tgsigqueueinfo, [](FEXCore::Core::CpuStateFrame *Frame, pid_t tgid, pid_t tid, int sig, siginfo_t *info) -> uint64_t {
       SYSCALL_STUB(rt_tgsigqueueinfo);
     });

unittests/gvisor-tests/Known_Failures

@@ -72,7 +72,6 @@ epoll_test
 exceptions_test
 exec_binary_test
 exec_test
-fallocate_test
 fcntl_test
 flock_test
 fork_test