diff options
Diffstat (limited to 'lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp')
| -rw-r--r-- | lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp | 121 |
1 files changed, 115 insertions, 6 deletions
diff --git a/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp b/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp index 339d33d25110..e3707365a9c3 100644 --- a/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp +++ b/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp @@ -137,12 +137,115 @@ bool ProcessFreeBSDKernel::DoUpdateThreadList(ThreadList &old_thread_list, return false; } - const Symbol *pcb_sym = - GetTarget().GetExecutableModule()->FindFirstSymbolWithNameAndType( - ConstString("dumppcb")); - ThreadSP thread_sp(new ThreadFreeBSDKernel( - *this, 1, pcb_sym ? pcb_sym->GetFileAddress() : LLDB_INVALID_ADDRESS)); - new_thread_list.AddThread(thread_sp); + Status error; + + // struct field offsets are written as symbols so that we don't have + // to figure them out ourselves + int32_t offset_p_list = ReadSignedIntegerFromMemory( + FindSymbol("proc_off_p_list"), 4, -1, error); + int32_t offset_p_pid = + ReadSignedIntegerFromMemory(FindSymbol("proc_off_p_pid"), 4, -1, error); + int32_t offset_p_threads = ReadSignedIntegerFromMemory( + FindSymbol("proc_off_p_threads"), 4, -1, error); + int32_t offset_p_comm = ReadSignedIntegerFromMemory( + FindSymbol("proc_off_p_comm"), 4, -1, error); + + int32_t offset_td_tid = ReadSignedIntegerFromMemory( + FindSymbol("thread_off_td_tid"), 4, -1, error); + int32_t offset_td_plist = ReadSignedIntegerFromMemory( + FindSymbol("thread_off_td_plist"), 4, -1, error); + int32_t offset_td_pcb = ReadSignedIntegerFromMemory( + FindSymbol("thread_off_td_pcb"), 4, -1, error); + int32_t offset_td_oncpu = ReadSignedIntegerFromMemory( + FindSymbol("thread_off_td_oncpu"), 4, -1, error); + int32_t offset_td_name = ReadSignedIntegerFromMemory( + FindSymbol("thread_off_td_name"), 4, -1, error); + + // fail if we were not able to read any of the offsets + if (offset_p_list == -1 || offset_p_pid == -1 || offset_p_threads == -1 || + offset_p_comm == -1 || offset_td_tid == -1 || offset_td_plist == -1 || + offset_td_pcb == -1 || offset_td_oncpu == -1 || offset_td_name == -1) + return false; + + // dumptid contains the thread-id of the crashing thread + // dumppcb contains its PCB + int32_t dumptid = + ReadSignedIntegerFromMemory(FindSymbol("dumptid"), 4, -1, error); + lldb::addr_t dumppcb = FindSymbol("dumppcb"); + + // stoppcbs is an array of PCBs on all CPUs + // each element is of size pcb_size + int32_t pcbsize = + ReadSignedIntegerFromMemory(FindSymbol("pcb_size"), 4, -1, error); + lldb::addr_t stoppcbs = FindSymbol("stoppcbs"); + + // from FreeBSD sys/param.h + constexpr size_t fbsd_maxcomlen = 19; + + // iterate through a linked list of all processes + // allproc is a pointer to the first list element, p_list field + // (found at offset_p_list) specifies the next element + for (lldb::addr_t proc = + ReadPointerFromMemory(FindSymbol("allproc"), error); + proc != 0 && proc != LLDB_INVALID_ADDRESS; + proc = ReadPointerFromMemory(proc + offset_p_list, error)) { + int32_t pid = + ReadSignedIntegerFromMemory(proc + offset_p_pid, 4, -1, error); + // process' command-line string + char comm[fbsd_maxcomlen + 1]; + ReadCStringFromMemory(proc + offset_p_comm, comm, sizeof(comm), error); + + // iterate through a linked list of all process' threads + // the initial thread is found in process' p_threads, subsequent + // elements are linked via td_plist field + for (lldb::addr_t td = + ReadPointerFromMemory(proc + offset_p_threads, error); + td != 0; td = ReadPointerFromMemory(td + offset_td_plist, error)) { + int32_t tid = + ReadSignedIntegerFromMemory(td + offset_td_tid, 4, -1, error); + lldb::addr_t pcb_addr = + ReadPointerFromMemory(td + offset_td_pcb, error); + // whether process was on CPU (-1 if not, otherwise CPU number) + int32_t oncpu = + ReadSignedIntegerFromMemory(td + offset_td_oncpu, 4, -2, error); + // thread name + char thread_name[fbsd_maxcomlen + 1]; + ReadCStringFromMemory(td + offset_td_name, thread_name, + sizeof(thread_name), error); + + // if we failed to read TID, ignore this thread + if (tid == -1) + continue; + + std::string thread_desc = llvm::formatv("(pid {0}) {1}", pid, comm); + if (*thread_name && strcmp(thread_name, comm)) { + thread_desc += '/'; + thread_desc += thread_name; + } + + // roughly: + // 1. if the thread crashed, its PCB is going to be at "dumppcb" + // 2. if the thread was on CPU, its PCB is going to be on the CPU + // 3. otherwise, its PCB is in the thread struct + if (tid == dumptid) { + // NB: dumppcb can be LLDB_INVALID_ADDRESS if reading it failed + pcb_addr = dumppcb; + thread_desc += " (crashed)"; + } else if (oncpu != -1) { + // if we managed to read stoppcbs and pcb_size, use them to find + // the correct PCB + if (stoppcbs != LLDB_INVALID_ADDRESS && pcbsize > 0) + pcb_addr = stoppcbs + oncpu * pcbsize; + else + pcb_addr = LLDB_INVALID_ADDRESS; + thread_desc += llvm::formatv(" (on CPU {0})", oncpu); + } + + ThreadSP thread_sp{ + new ThreadFreeBSDKernel(*this, tid, pcb_addr, thread_desc)}; + new_thread_list.AddThread(thread_sp); + } + } } else { const uint32_t num_threads = old_thread_list.GetSize(false); for (uint32_t i = 0; i < num_threads; ++i) @@ -163,6 +266,12 @@ DynamicLoader *ProcessFreeBSDKernel::GetDynamicLoader() { return m_dyld_up.get(); } +lldb::addr_t ProcessFreeBSDKernel::FindSymbol(const char *name) { + ModuleSP mod_sp = GetTarget().GetExecutableModule(); + const Symbol *sym = mod_sp->FindFirstSymbolWithNameAndType(ConstString(name)); + return sym ? sym->GetLoadAddress(&GetTarget()) : LLDB_INVALID_ADDRESS; +} + #if LLDB_ENABLE_FBSDVMCORE ProcessFreeBSDKernelFVC::ProcessFreeBSDKernelFVC(lldb::TargetSP target_sp, |