SyscallsSMCTracking: Workaround assert in ELF mapping

The ELF tracking thing has an expectation that only portions of ELF
files that are described in the program headers will be mapped
executable. This doesn't hold true as programs will remap random
portions of ELF files as executable. In the case that this occurs, don't
assert out and instead print a warning.

This was discovered as Node.js remaps a portion of itself executable
that isn't described as such in the program headers. I also have a local
unittest that exposes the same problem. I had discovered same problem in
some other program with #5038.

Also fixes a bug where sometimes completely anonymously mapped
executable sneak in and cause a crash, which is kind of silly.

Author: Sonicadvance1

Source/Tools/LinuxEmulation/LinuxSyscalls/SyscallsSMCTracking.cpp

@@ -479,22 +479,30 @@ std::optional<SyscallHandler::LateApplyExtendedVolatileMetadata> SyscallHandler:
             (ProtMapping.Executable ? PF_X : 0) | (ProtMapping.Writable ? PF_W : 0) | (ProtMapping.Readable ? PF_R : 0));
           return std::ranges::find(ExpectedBases, Resource.FirstVMA->Base) != ExpectedBases.end();
         });
-        LOGMAN_THROW_A_FMT(ResourceIt != ResourceEnd, "ERROR: Could not find base for file mapping at {:#x} (offset {:#x})", addr, offset);
-        Resource = &ResourceIt->second;
+        if (ResourceIt == ResourceEnd) {
+          // This isn't necessarily a fatal exception. It just means the ELF section isn't a part of the ELF Program headers.
+          // Node.js hits this as it maps a section of itself that isn't a part of the program headers.
+          LogMan::Msg::IFmt("Warning: Could not find base for file mapping at {:#x} (offset {:#x}): {}", addr, offset,
+                            std::string_view(Tmp, PathLength));
+        } else {
+          Resource = &ResourceIt->second;
+        }
       }
 
-      const fextl::string Filename = FHU::Filesystem::GetFilename(Resource->MappedFile->Filename);
+      if (Resource->MappedFile) {
+        const fextl::string Filename = FHU::Filesystem::GetFilename(Resource->MappedFile->Filename);
 
-      // We now have the filename and the offset in the filename getting mapped.
-      // Check for extended volatile metadata.
-      auto it = ExtendedMetaData.find(Filename);
-      if (it != ExtendedMetaData.end()) {
-        SyscallHandler::LateApplyExtendedVolatileMetadata LateMetadata;
-        FEX::VolatileMetadata::ApplyFEXExtendedVolatileMetadata(
-          it->second, LateMetadata.VolatileInstructions, LateMetadata.VolatileValidRanges, addr, addr + length, offset, offset + length);
+        // We now have the filename and the offset in the filename getting mapped.
+        // Check for extended volatile metadata.
+        auto it = ExtendedMetaData.find(Filename);
+        if (it != ExtendedMetaData.end()) {
+          SyscallHandler::LateApplyExtendedVolatileMetadata LateMetadata;
+          FEX::VolatileMetadata::ApplyFEXExtendedVolatileMetadata(
+            it->second, LateMetadata.VolatileInstructions, LateMetadata.VolatileValidRanges, addr, addr + length, offset, offset + length);
 
-        if (!LateMetadata.VolatileInstructions.empty() || !LateMetadata.VolatileValidRanges.Empty()) {
-          VolatileMetadata.emplace(std::move(LateMetadata));
+          if (!LateMetadata.VolatileInstructions.empty() || !LateMetadata.VolatileValidRanges.Empty()) {
+            VolatileMetadata.emplace(std::move(LateMetadata));
+          }
         }
       }
     }