Linux: Disable EFAULT handler until we find something that uses it.

FEX-Emu · Jan 18, 2024 · cd9a1a3 · cd9a1a3
1 parent 92ef9e7
commit cd9a1a3
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Showing 3 changed files with 13 additions and 4 deletions.
diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/SignalDelegator.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/SignalDelegator.cpp
@@ -1471,9 +1471,16 @@ namespace FEX::HLE {
       else if (Signal == SIGSEGV &&
                (reinterpret_cast<void*>(ArchHelpers::Context::GetPc(UContext)) == FaultSafeMemcpy::CopyFromUser_FaultLocation ||
                reinterpret_cast<void*>(ArchHelpers::Context::GetPc(UContext)) == FaultSafeMemcpy::CopyToUser_FaultLocation)) {
-        // Jump to the copy fault handler return trampoline to safely return EFAULT.
-        ArchHelpers::Context::SetPc(UContext, reinterpret_cast<uint64_t>(&FaultSafeMemcpy::CopyFaultTrampoline));
-        return;
+        // If you want to emulate EFAULT behaviour then enable this if-statement.
+        // Do this once we find an application that depends on this.
+        if constexpr (false) {
+          // Jump to the copy fault handler return trampoline to safely return EFAULT.
+          ArchHelpers::Context::SetPc(UContext, reinterpret_cast<uint64_t>(&FaultSafeMemcpy::CopyFaultTrampoline));
+          return;
+        }
+        else {
+          LogMan::Msg::AFmt("Received invalid data to syscall. Crashing now!");
+        }
       }
       else {
         if (IsAsyncSignal(&SigInfo, Signal) && MustDeferSignal) {

diff --git a/unittests/FEXLinuxTests/Known_Failures b/unittests/FEXLinuxTests/Known_Failures
@@ -19,3 +19,5 @@ sigtest_samask.32
 sigtest_samask.64
 sigtest_sigmask.32
 sigtest_sigmask.64
+
+syscalls_efault.32
diff --git a/unittests/FEXLinuxTests/tests/syscalls/syscalls_efault.cpp b/unittests/FEXLinuxTests/tests/syscalls/syscalls_efault.cpp
@@ -15,7 +15,7 @@ TEST_CASE("poll") {
   CHECK(errno == EFAULT);
 }
 
-TEST_CASE("ppoll") {
+TEST_CASE("ppoll", "[!mayfail]") {
   // ppoll can return EFAULT for arguements 1, 3, 4
   struct pollfd *invalid_fds = reinterpret_cast<struct pollfd *>(mmap(nullptr, sysconf(_SC_PAGESIZE), PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
   struct timespec *invalid_timespec = reinterpret_cast<struct timespec*>(mmap(nullptr, sysconf(_SC_PAGESIZE), PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));