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[lldb/gdb-remote] Remove ancient debugserver workaround

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This workaround is the source of an awkwared Process->Platform
dependency. While this could be solved in various ways (the only thing
we really use is the plugin name), it may be better to just remove it --
the workaround was added 10 years ago (43c555dfc), and the affected
debugservers were "old" even then, so hopefully they are not in use
anymore.

Differential Revision: https://reviews.llvm.org/D121305
This commit is contained in:
Pavel Labath 2022-03-09 18:19:58 +01:00
parent 72276bdaff
commit ed1a83befe
3 changed files with 1 additions and 107 deletions
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1
lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
View file

@ -8,7 +8,6 @@ lldb_tablegen(ProcessGDBRemotePropertiesEnum.inc -gen-lldb-property-enum-defs
set(LLDB_PLUGINS
lldbPluginProcessUtility
lldbPluginPlatformMacOSX
)
if(HAVE_LIBCOMPRESSION)

106
lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
View file

@ -74,7 +74,6 @@
#include "GDBRemoteRegisterContext.h"
#include "GDBRemoteRegisterFallback.h"
#include "Plugins/Platform/MacOSX/PlatformRemoteiOS.h"
#include "Plugins/Process/Utility/GDBRemoteSignals.h"
#include "Plugins/Process/Utility/InferiorCallPOSIX.h"
#include "Plugins/Process/Utility/StopInfoMachException.h"
@ -253,7 +252,7 @@ ProcessGDBRemote::ProcessGDBRemote(lldb::TargetSP target_sp,
m_continue_C_tids(), m_continue_s_tids(), m_continue_S_tids(),
m_max_memory_size(0), m_remote_stub_max_memory_size(0),
m_addr_to_mmap_size(), m_thread_create_bp_sp(),
m_waiting_for_attach(false), m_destroy_tried_resuming(false),
m_waiting_for_attach(false),
m_command_sp(), m_breakpoint_pc_offset(0),
m_initial_tid(LLDB_INVALID_THREAD_ID), m_allow_flash_writes(false),
m_erased_flash_ranges(), m_vfork_in_progress(false) {
@ -2380,109 +2379,6 @@ Status ProcessGDBRemote::DoDestroy() {
Log *log = GetLog(GDBRLog::Process);
LLDB_LOGF(log, "ProcessGDBRemote::DoDestroy()");
// There is a bug in older iOS debugservers where they don't shut down the
// process they are debugging properly. If the process is sitting at a
// breakpoint or an exception, this can cause problems with restarting. So
// we check to see if any of our threads are stopped at a breakpoint, and if
// so we remove all the breakpoints, resume the process, and THEN destroy it
// again.
//
// Note, we don't have a good way to test the version of debugserver, but I
// happen to know that the set of all the iOS debugservers which don't
// support GetThreadSuffixSupported() and that of the debugservers with this
// bug are equal. There really should be a better way to test this!
//
// We also use m_destroy_tried_resuming to make sure we only do this once, if
// we resume and then halt and get called here to destroy again and we're
// still at a breakpoint or exception, then we should just do the straight-
// forward kill.
//
// And of course, if we weren't able to stop the process by the time we get
// here, it isn't necessary (or helpful) to do any of this.
if (!m_gdb_comm.GetThreadSuffixSupported() &&
m_public_state.GetValue() != eStateRunning) {
PlatformSP platform_sp = GetTarget().GetPlatform();
if (platform_sp && platform_sp->GetPluginName() ==
PlatformRemoteiOS::GetPluginNameStatic()) {
if (m_destroy_tried_resuming) {
if (log)
log->PutCString("ProcessGDBRemote::DoDestroy() - Tried resuming to "
"destroy once already, not doing it again.");
} else {
// At present, the plans are discarded and the breakpoints disabled
// Process::Destroy, but we really need it to happen here and it
// doesn't matter if we do it twice.
m_thread_list.DiscardThreadPlans();
DisableAllBreakpointSites();
bool stop_looks_like_crash = false;
ThreadList &threads = GetThreadList();
{
std::lock_guard<std::recursive_mutex> guard(threads.GetMutex());
size_t num_threads = threads.GetSize();
for (size_t i = 0; i < num_threads; i++) {
ThreadSP thread_sp = threads.GetThreadAtIndex(i);
StopInfoSP stop_info_sp = thread_sp->GetPrivateStopInfo();
StopReason reason = eStopReasonInvalid;
if (stop_info_sp)
reason = stop_info_sp->GetStopReason();
if (reason == eStopReasonBreakpoint ||
reason == eStopReasonException) {
LLDB_LOGF(log,
"ProcessGDBRemote::DoDestroy() - thread: 0x%4.4" PRIx64
" stopped with reason: %s.",
thread_sp->GetProtocolID(),
stop_info_sp->GetDescription());
stop_looks_like_crash = true;
break;
}
}
}
if (stop_looks_like_crash) {
if (log)
log->PutCString("ProcessGDBRemote::DoDestroy() - Stopped at a "
"breakpoint, continue and then kill.");
m_destroy_tried_resuming = true;
// If we are going to run again before killing, it would be good to
// suspend all the threads before resuming so they won't get into
// more trouble. Sadly, for the threads stopped with the breakpoint
// or exception, the exception doesn't get cleared if it is
// suspended, so we do have to run the risk of letting those threads
// proceed a bit.
{
std::lock_guard<std::recursive_mutex> guard(threads.GetMutex());
size_t num_threads = threads.GetSize();
for (size_t i = 0; i < num_threads; i++) {
ThreadSP thread_sp = threads.GetThreadAtIndex(i);
StopInfoSP stop_info_sp = thread_sp->GetPrivateStopInfo();
StopReason reason = eStopReasonInvalid;
if (stop_info_sp)
reason = stop_info_sp->GetStopReason();
if (reason != eStopReasonBreakpoint &&
reason != eStopReasonException) {
LLDB_LOGF(log,
"ProcessGDBRemote::DoDestroy() - Suspending "
"thread: 0x%4.4" PRIx64 " before running.",
thread_sp->GetProtocolID());
thread_sp->SetResumeState(eStateSuspended);
}
}
}
Resume();
return Destroy(false);
}
}
}
}
// Interrupt if our inferior is running...
int exit_status = SIGABRT;
std::string exit_string;

1
lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
View file

@ -281,7 +281,6 @@ protected:
MMapMap m_addr_to_mmap_size;
lldb::BreakpointSP m_thread_create_bp_sp;
bool m_waiting_for_attach;
bool m_destroy_tried_resuming;
lldb::CommandObjectSP m_command_sp;
int64_t m_breakpoint_pc_offset;
lldb::tid_t m_initial_tid; // The initial thread ID, given by stub on attach