Accessing a directory on my custom distributed filesystem results in a kernel panic. According to the backtrace, the last function called before the panic is triggered is mac_label_verify(). See the backtrace file attached. mac_label_verify-panic.txt The panic manifests itself given the following conditions: Machine-a: make a directory in Finder. Machine-b: remove the directory created on machine-a in Finder. Machine-a: access the directory removed on machine-b in Finder. Kernel panic ensues. The panic is reproducible on both Apple Silicon and x86-64. The backtrace is for x86-64 as I wasn't able to symbolicate it on Apple Silicon. Not sure how to tackle this one. Any pointers would be much appreciated.

In some recent releases of macos (14.x and 15.x), we have noticed what seems to be a slower dlopen() implementation. I don't have any numbers to support this theory. I happened to notice this "slowness" when investigating something unrelated. In one part of the code we have a call of the form: const char * fooBarLib = ....; dlopen(fooBarLib, RTLD_NOW + RTLD_GLOBAL); It so happened that due to some timing related issues, the process was crashing. A slow execution of code in this part of the code would trigger an issue in some other part of the code that would then lead to a process crash. The crash itself isn't a concern, because it's an internal issue that will addressed in the application code. What was interesting is that the slowness appears to be contributed by the call to dlopen(). Specifically, whenever a slowness was observed, the crash reports showed stack frames of the form: Thread 1: 0 dyld 0x18f08b5b4 _kernelrpc_mach_vm_protect_trap + 8 1 dyld 0x18f08f540 vm_protect + 52 2 dyld 0x18f0b87e0 lsl::MemoryManager::writeProtect(bool) + 204 3 dyld 0x18f0a7fe4 invocation function for block in dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 932 4 dyld 0x18f0e629c invocation function for block in dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 172 5 dyld 0x18f0d9c38 invocation function for block in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const + 496 6 dyld 0x18f08c2dc dyld3::MachOFile::forEachLoadCommand(Diagnostics&, void (load_command const*, bool&) block_pointer) const + 300 7 dyld 0x18f0d8bcc dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const + 192 8 dyld 0x18f0db5a0 dyld3::MachOFile::forEachInitializerPointerSection(Diagnostics&, void (unsigned int, unsigned int, bool&) block_pointer) const + 160 9 dyld 0x18f0e5f90 dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 432 10 dyld 0x18f0a7bb4 dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 176 11 dyld 0x18f0af190 dyld4::JustInTimeLoader::runInitializers(dyld4::RuntimeState&) const + 36 12 dyld 0x18f0a8270 dyld4::Loader::runInitializersBottomUp(dyld4::RuntimeState&, dyld3::Array<dyld4::Loader const*>&, dyld3::Array<dyld4::Loader const*>&) const + 312 13 dyld 0x18f0ac560 dyld4::Loader::runInitializersBottomUpPlusUpwardLinks(dyld4::RuntimeState&) const::$_0::operator()() const + 180 14 dyld 0x18f0a8460 dyld4::Loader::runInitializersBottomUpPlusUpwardLinks(dyld4::RuntimeState&) const + 412 15 dyld 0x18f0c089c dyld4::APIs::dlopen_from(char const*, int, void*) + 2432 16 libjli.dylib 0x1025515b4 DoFooBar + 56 17 libjli.dylib 0x10254d2c0 Hello_World_Launch + 1160 18 helloworld 0x10250bbb4 main + 404 19 libjli.dylib 0x102552148 apple_main + 88 20 libsystem_pthread.dylib 0x18f4132e4 _pthread_start + 136 21 libsystem_pthread.dylib 0x18f40e0fc thread_start + 8 So, out of curiosity, have there been any known changes in the implementation of dlopen() which might explain the slowness? Like I noted, I don't have concrete numbers, but to quantify the slowness I don't think it's slower by a noticeable amount - maybe a few milli seconds. I guess what I am trying to understand is, whether there's anything that needs attention here.

https://github.com/apple-oss-distributions/lsof/blob/c48c28f51e82a5d682a4459bdbdc42face73468f/lsof/dialects/darwin/libproc/dproc.c#L753 proc_pidinfo(pid, PROC_PIDLISTFILEPORTS, 0, NULL, 0)) the retval of proc_pidinfo is always zero how lsof works?